Merge pull request #516 from sigp/interop

Interop

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "tests/ef_tests/eth2.0-spec-tests"]
-	path = tests/ef_tests/eth2.0-spec-tests
-	url = https://github.com/ethereum/eth2.0-spec-tests

Cargo.toml

@@ -12,6 +12,7 @@ members = [
 	"eth2/utils/logging",
 	"eth2/utils/eth2_hashing",
 	"eth2/utils/lighthouse_metrics",
+	"eth2/utils/lighthouse_bootstrap",
 	"eth2/utils/merkle_proof",
 	"eth2/utils/int_to_bytes",
 	"eth2/utils/serde_hex",
@@ -32,8 +33,9 @@ members = [
     "beacon_node/rpc",
 	"beacon_node/version",
 	"beacon_node/beacon_chain",
+	"beacon_node/websocket_server",
 	"tests/ef_tests",
-	"tests/cli_util",
+	"lcli",
 	"protos",
 	"validator_client",
 	"account_manager",

Makefile

@@ -0,0 +1,31 @@
+TESTS_TAG := v0.8.3
+TESTS = general minimal mainnet
+
+TESTS_BASE_DIR := ./tests/ef_tests
+REPO_NAME := eth2.0-spec-tests
+OUTPUT_DIR := $(TESTS_BASE_DIR)/$(REPO_NAME)
+
+BASE_URL := https://github.com/ethereum/$(REPO_NAME)/releases/download/$(SPEC_VERSION)
+
+release:
+	cargo build --all --release
+
+clean_ef_tests:
+	rm -r $(OUTPUT_DIR)
+
+ef_tests: download_tests extract_tests
+	mkdir $(OUTPUT_DIR)
+	for test in $(TESTS); do \
+		tar -C $(OUTPUT_DIR) -xvf $(TESTS_BASE_DIR)/$$test.tar ;\
+		rm $(TESTS_BASE_DIR)/$$test.tar ;\
+	done
+
+extract_tests:
+	for test in $(TESTS); do \
+		gzip -df $(TESTS_BASE_DIR)/$$test.tar.gz ;\
+	done
+
+download_tests:
+	for test in $(TESTS); do \
+		wget -P $(TESTS_BASE_DIR) $(BASE_URL)/$$test.tar.gz; \
+	done

account_manager/src/main.rs

@@ -125,9 +125,13 @@ fn main() {
                 }
             }
         }
-        _ => panic!(
-            "The account manager must be run with a subcommand. See help for more information."
-        ),
+        _ => {
+            crit!(
+                log,
+                "The account manager must be run with a subcommand. See help for more information."
+            );
+            return;
+        }
     }
 }
 

beacon_node/Cargo.toml

@@ -6,11 +6,14 @@ edition = "2018"
 
 [dependencies]
 eth2_config = { path = "../eth2/utils/eth2_config" }
+lighthouse_bootstrap = { path = "../eth2/utils/lighthouse_bootstrap" }
+beacon_chain = { path = "beacon_chain" }
 types = { path = "../eth2/types" }
 store = { path = "./store" }
 client = { path = "client" }
 version = { path = "version" }
 clap = "2.32.0"
+rand = "0.7"
 slog = { version = "^2.2.3" , features = ["max_level_trace", "release_max_level_trace"] }
 slog-term = "^2.4.0"
 slog-async = "^2.3.0"

beacon_node/beacon_chain/Cargo.toml

@@ -4,19 +4,29 @@ version = "0.1.0"
 authors = ["Paul Hauner <paul@paulhauner.com>", "Age Manning <Age@AgeManning.com>"]
 edition = "2018"
 
+[features]
+
+write_ssz_files = []  # Writes debugging .ssz files to /tmp during block processing.
+
 [dependencies]
+eth2_config = { path = "../../eth2/utils/eth2_config" }
+merkle_proof = { path = "../../eth2/utils/merkle_proof" }
 store = { path = "../store" }
 parking_lot = "0.7"
 lazy_static = "1.3.0"
 lighthouse_metrics = { path = "../../eth2/utils/lighthouse_metrics" }
+lighthouse_bootstrap = { path = "../../eth2/utils/lighthouse_bootstrap" }
 log = "0.4"
 operation_pool = { path = "../../eth2/operation_pool" }
 rayon = "1.0"
 serde = "1.0"
 serde_derive = "1.0"
+serde_yaml = "0.8"
+serde_json = "^1.0"
 slog = { version = "^2.2.3" , features = ["max_level_trace"] }
 sloggers = { version = "^0.3" }
 slot_clock = { path = "../../eth2/utils/slot_clock" }
+eth2_hashing = { path = "../../eth2/utils/eth2_hashing" }
 eth2_ssz = "0.1"
 eth2_ssz_derive = "0.1"
 state_processing = { path = "../../eth2/state_processing" }

beacon_node/beacon_chain/src/beacon_chain_builder.rs

@@ -0,0 +1,334 @@
+use crate::{BeaconChain, BeaconChainTypes};
+use eth2_hashing::hash;
+use lighthouse_bootstrap::Bootstrapper;
+use merkle_proof::MerkleTree;
+use rayon::prelude::*;
+use slog::Logger;
+use ssz::{Decode, Encode};
+use state_processing::initialize_beacon_state_from_eth1;
+use std::fs::File;
+use std::io::prelude::*;
+use std::path::PathBuf;
+use std::sync::Arc;
+use std::time::SystemTime;
+use tree_hash::{SignedRoot, TreeHash};
+use types::{
+    BeaconBlock, BeaconState, ChainSpec, Deposit, DepositData, Domain, EthSpec, Fork, Hash256,
+    Keypair, PublicKey, Signature,
+};
+
+enum BuildStrategy<T: BeaconChainTypes> {
+    FromGenesis {
+        genesis_state: Box<BeaconState<T::EthSpec>>,
+        genesis_block: Box<BeaconBlock<T::EthSpec>>,
+    },
+    LoadFromStore,
+}
+
+pub struct BeaconChainBuilder<T: BeaconChainTypes> {
+    build_strategy: BuildStrategy<T>,
+    spec: ChainSpec,
+    log: Logger,
+}
+
+impl<T: BeaconChainTypes> BeaconChainBuilder<T> {
+    pub fn recent_genesis(
+        keypairs: &[Keypair],
+        minutes: u64,
+        spec: ChainSpec,
+        log: Logger,
+    ) -> Result<Self, String> {
+        Self::quick_start(recent_genesis_time(minutes), keypairs, spec, log)
+    }
+
+    pub fn quick_start(
+        genesis_time: u64,
+        keypairs: &[Keypair],
+        spec: ChainSpec,
+        log: Logger,
+    ) -> Result<Self, String> {
+        let genesis_state = interop_genesis_state(keypairs, genesis_time, &spec)?;
+
+        Ok(Self::from_genesis_state(genesis_state, spec, log))
+    }
+
+    pub fn yaml_state(file: &PathBuf, spec: ChainSpec, log: Logger) -> Result<Self, String> {
+        let file = File::open(file.clone())
+            .map_err(|e| format!("Unable to open YAML genesis state file {:?}: {:?}", file, e))?;
+
+        let genesis_state = serde_yaml::from_reader(file)
+            .map_err(|e| format!("Unable to parse YAML genesis state file: {:?}", e))?;
+
+        Ok(Self::from_genesis_state(genesis_state, spec, log))
+    }
+
+    pub fn ssz_state(file: &PathBuf, spec: ChainSpec, log: Logger) -> Result<Self, String> {
+        let mut file = File::open(file.clone())
+            .map_err(|e| format!("Unable to open SSZ genesis state file {:?}: {:?}", file, e))?;
+
+        let mut bytes = vec![];
+        file.read_to_end(&mut bytes)
+            .map_err(|e| format!("Failed to read SSZ file: {:?}", e))?;
+
+        let genesis_state = BeaconState::from_ssz_bytes(&bytes)
+            .map_err(|e| format!("Unable to parse SSZ genesis state file: {:?}", e))?;
+
+        Ok(Self::from_genesis_state(genesis_state, spec, log))
+    }
+
+    pub fn json_state(file: &PathBuf, spec: ChainSpec, log: Logger) -> Result<Self, String> {
+        let file = File::open(file.clone())
+            .map_err(|e| format!("Unable to open JSON genesis state file {:?}: {:?}", file, e))?;
+
+        let genesis_state = serde_json::from_reader(file)
+            .map_err(|e| format!("Unable to parse JSON genesis state file: {:?}", e))?;
+
+        Ok(Self::from_genesis_state(genesis_state, spec, log))
+    }
+
+    pub fn http_bootstrap(server: &str, spec: ChainSpec, log: Logger) -> Result<Self, String> {
+        let bootstrapper = Bootstrapper::connect(server.to_string(), &log)
+            .map_err(|e| format!("Failed to initialize bootstrap client: {}", e))?;
+
+        let (genesis_state, genesis_block) = bootstrapper
+            .genesis()
+            .map_err(|e| format!("Failed to bootstrap genesis state: {}", e))?;
+
+        Ok(Self {
+            build_strategy: BuildStrategy::FromGenesis {
+                genesis_block: Box::new(genesis_block),
+                genesis_state: Box::new(genesis_state),
+            },
+            spec,
+            log,
+        })
+    }
+
+    fn from_genesis_state(
+        genesis_state: BeaconState<T::EthSpec>,
+        spec: ChainSpec,
+        log: Logger,
+    ) -> Self {
+        Self {
+            build_strategy: BuildStrategy::FromGenesis {
+                genesis_block: Box::new(genesis_block(&genesis_state, &spec)),
+                genesis_state: Box::new(genesis_state),
+            },
+            spec,
+            log,
+        }
+    }
+
+    pub fn from_store(spec: ChainSpec, log: Logger) -> Self {
+        Self {
+            build_strategy: BuildStrategy::LoadFromStore,
+            spec,
+            log,
+        }
+    }
+
+    pub fn build(
+        self,
+        store: Arc<T::Store>,
+        eth1_backend: T::Eth1Chain,
+        event_handler: T::EventHandler,
+    ) -> Result<BeaconChain<T>, String> {
+        Ok(match self.build_strategy {
+            BuildStrategy::LoadFromStore => {
+                BeaconChain::from_store(store, eth1_backend, event_handler, self.spec, self.log)
+                    .map_err(|e| format!("Error loading BeaconChain from database: {:?}", e))?
+                    .ok_or_else(|| format!("Unable to find exising BeaconChain in database."))?
+            }
+            BuildStrategy::FromGenesis {
+                genesis_block,
+                genesis_state,
+            } => BeaconChain::from_genesis(
+                store,
+                eth1_backend,
+                event_handler,
+                genesis_state.as_ref().clone(),
+                genesis_block.as_ref().clone(),
+                self.spec,
+                self.log,
+            )
+            .map_err(|e| format!("Failed to initialize new beacon chain: {:?}", e))?,
+        })
+    }
+}
+
+fn genesis_block<T: EthSpec>(genesis_state: &BeaconState<T>, spec: &ChainSpec) -> BeaconBlock<T> {
+    let mut genesis_block = BeaconBlock::empty(&spec);
+
+    genesis_block.state_root = genesis_state.canonical_root();
+
+    genesis_block
+}
+
+/// Builds a genesis state as defined by the Eth2 interop procedure (see below).
+///
+/// Reference:
+/// https://github.com/ethereum/eth2.0-pm/tree/6e41fcf383ebeb5125938850d8e9b4e9888389b4/interop/mocked_start
+fn interop_genesis_state<T: EthSpec>(
+    keypairs: &[Keypair],
+    genesis_time: u64,
+    spec: &ChainSpec,
+) -> Result<BeaconState<T>, String> {
+    let eth1_block_hash = Hash256::from_slice(&[0x42; 32]);
+    let eth1_timestamp = 2_u64.pow(40);
+    let amount = spec.max_effective_balance;
+
+    let withdrawal_credentials = |pubkey: &PublicKey| {
+        let mut credentials = hash(&pubkey.as_ssz_bytes());
+        credentials[0] = spec.bls_withdrawal_prefix_byte;
+        Hash256::from_slice(&credentials)
+    };
+
+    let datas = keypairs
+        .into_par_iter()
+        .map(|keypair| {
+            let mut data = DepositData {
+                withdrawal_credentials: withdrawal_credentials(&keypair.pk),
+                pubkey: keypair.pk.clone().into(),
+                amount,
+                signature: Signature::empty_signature().into(),
+            };
+
+            let domain = spec.get_domain(
+                spec.genesis_slot.epoch(T::slots_per_epoch()),
+                Domain::Deposit,
+                &Fork::default(),
+            );
+            data.signature = Signature::new(&data.signed_root()[..], domain, &keypair.sk).into();
+
+            data
+        })
+        .collect::<Vec<_>>();
+
+    let deposit_root_leaves = datas
+        .par_iter()
+        .map(|data| Hash256::from_slice(&data.tree_hash_root()))
+        .collect::<Vec<_>>();
+
+    let mut proofs = vec![];
+    for i in 1..=deposit_root_leaves.len() {
+        // Note: this implementation is not so efficient.
+        //
+        // If `MerkleTree` had a push method, we could just build one tree and sample it instead of
+        // rebuilding the tree for each deposit.
+        let tree = MerkleTree::create(
+            &deposit_root_leaves[0..i],
+            spec.deposit_contract_tree_depth as usize,
+        );
+
+        let (_, mut proof) = tree.generate_proof(i - 1, spec.deposit_contract_tree_depth as usize);
+        proof.push(Hash256::from_slice(&int_to_bytes32(i)));
+
+        assert_eq!(
+            proof.len(),
+            spec.deposit_contract_tree_depth as usize + 1,
+            "Deposit proof should be correct len"
+        );
+
+        proofs.push(proof);
+    }
+
+    let deposits = datas
+        .into_par_iter()
+        .zip(proofs.into_par_iter())
+        .map(|(data, proof)| (data, proof.into()))
+        .map(|(data, proof)| Deposit { proof, data })
+        .collect::<Vec<_>>();
+
+    let mut state =
+        initialize_beacon_state_from_eth1(eth1_block_hash, eth1_timestamp, deposits, spec)
+            .map_err(|e| format!("Unable to initialize genesis state: {:?}", e))?;
+
+    state.genesis_time = genesis_time;
+
+    // Invalid all the caches after all the manual state surgery.
+    state.drop_all_caches();
+
+    Ok(state)
+}
+
+/// Returns `int` as little-endian bytes with a length of 32.
+fn int_to_bytes32(int: usize) -> Vec<u8> {
+    let mut vec = int.to_le_bytes().to_vec();
+    vec.resize(32, 0);
+    vec
+}
+
+/// Returns the system time, mod 30 minutes.
+///
+/// Used for easily creating testnets.
+fn recent_genesis_time(minutes: u64) -> u64 {
+    let now = SystemTime::now()
+        .duration_since(SystemTime::UNIX_EPOCH)
+        .unwrap()
+        .as_secs();
+    let secs_after_last_period = now.checked_rem(minutes * 60).unwrap_or(0);
+    now - secs_after_last_period
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use types::{test_utils::generate_deterministic_keypairs, EthSpec, MinimalEthSpec};
+
+    type TestEthSpec = MinimalEthSpec;
+
+    #[test]
+    fn interop_state() {
+        let validator_count = 16;
+        let genesis_time = 42;
+        let spec = &TestEthSpec::default_spec();
+
+        let keypairs = generate_deterministic_keypairs(validator_count);
+
+        let state = interop_genesis_state::<TestEthSpec>(&keypairs, genesis_time, spec)
+            .expect("should build state");
+
+        assert_eq!(
+            state.eth1_data.block_hash,
+            Hash256::from_slice(&[0x42; 32]),
+            "eth1 block hash should be co-ordinated junk"
+        );
+
+        assert_eq!(
+            state.genesis_time, genesis_time,
+            "genesis time should be as specified"
+        );
+
+        for b in &state.balances {
+            assert_eq!(
+                *b, spec.max_effective_balance,
+                "validator balances should be max effective balance"
+            );
+        }
+
+        for v in &state.validators {
+            let creds = v.withdrawal_credentials.as_bytes();
+            assert_eq!(
+                creds[0], spec.bls_withdrawal_prefix_byte,
+                "first byte of withdrawal creds should be bls prefix"
+            );
+            assert_eq!(
+                &creds[1..],
+                &hash(&v.pubkey.as_ssz_bytes())[1..],
+                "rest of withdrawal creds should be pubkey hash"
+            )
+        }
+
+        assert_eq!(
+            state.balances.len(),
+            validator_count,
+            "validator balances len should be correct"
+        );
+
+        assert_eq!(
+            state.validators.len(),
+            validator_count,
+            "validator count should be correct"
+        );
+    }
+}

beacon_node/beacon_chain/src/errors.rs

@@ -1,3 +1,4 @@
+use crate::eth1_chain::Error as Eth1ChainError;
 use crate::fork_choice::Error as ForkChoiceError;
 use state_processing::per_block_processing::errors::AttestationValidationError;
 use state_processing::BlockProcessingError;
@@ -23,6 +24,8 @@ pub enum BeaconChainError {
         previous_epoch: Epoch,
         new_epoch: Epoch,
     },
+    SlotClockDidNotStart,
+    NoStateForSlot(Slot),
     UnableToFindTargetRoot(Slot),
     BeaconStateError(BeaconStateError),
     DBInconsistent(String),
@@ -31,24 +34,30 @@ pub enum BeaconChainError {
     MissingBeaconBlock(Hash256),
     MissingBeaconState(Hash256),
     SlotProcessingError(SlotProcessingError),
+    UnableToAdvanceState(String),
     NoStateForAttestation {
         beacon_block_root: Hash256,
     },
     AttestationValidationError(AttestationValidationError),
+    /// Returned when an internal check fails, indicating corrupt data.
+    InvariantViolated(String),
 }
 
 easy_from_to!(SlotProcessingError, BeaconChainError);
+easy_from_to!(AttestationValidationError, BeaconChainError);
 
 #[derive(Debug, PartialEq)]
 pub enum BlockProductionError {
     UnableToGetBlockRootFromState,
     UnableToReadSlot,
+    UnableToProduceAtSlot(Slot),
     SlotProcessingError(SlotProcessingError),
     BlockProcessingError(BlockProcessingError),
+    Eth1ChainError(Eth1ChainError),
     BeaconStateError(BeaconStateError),
 }
 
 easy_from_to!(BlockProcessingError, BlockProductionError);
 easy_from_to!(BeaconStateError, BlockProductionError);
 easy_from_to!(SlotProcessingError, BlockProductionError);
-easy_from_to!(AttestationValidationError, BeaconChainError);
+easy_from_to!(Eth1ChainError, BlockProductionError);

beacon_node/beacon_chain/src/eth1_chain.rs

@@ -0,0 +1,110 @@
+use crate::BeaconChainTypes;
+use eth2_hashing::hash;
+use std::marker::PhantomData;
+use types::{BeaconState, Deposit, Eth1Data, EthSpec, Hash256};
+
+type Result<T> = std::result::Result<T, Error>;
+
+/// Holds an `Eth1ChainBackend` and serves requests from the `BeaconChain`.
+pub struct Eth1Chain<T: BeaconChainTypes> {
+    backend: T::Eth1Chain,
+}
+
+impl<T: BeaconChainTypes> Eth1Chain<T> {
+    pub fn new(backend: T::Eth1Chain) -> Self {
+        Self { backend }
+    }
+
+    /// Returns the `Eth1Data` that should be included in a block being produced for the given
+    /// `state`.
+    pub fn eth1_data_for_block_production(
+        &self,
+        state: &BeaconState<T::EthSpec>,
+    ) -> Result<Eth1Data> {
+        self.backend.eth1_data(state)
+    }
+
+    /// Returns a list of `Deposits` that may be included in a block.
+    ///
+    /// Including all of the returned `Deposits` in a block should _not_ cause it to become
+    /// invalid.
+    pub fn deposits_for_block_inclusion(
+        &self,
+        state: &BeaconState<T::EthSpec>,
+    ) -> Result<Vec<Deposit>> {
+        let deposits = self.backend.queued_deposits(state)?;
+
+        // TODO: truncate deposits if required.
+
+        Ok(deposits)
+    }
+}
+
+#[derive(Debug, PartialEq)]
+pub enum Error {
+    /// Unable to return an Eth1Data for the given epoch.
+    EpochUnavailable,
+    /// An error from the backend service (e.g., the web3 data fetcher).
+    BackendError(String),
+}
+
+pub trait Eth1ChainBackend<T: EthSpec>: Sized + Send + Sync {
+    fn new(server: String) -> Result<Self>;
+
+    /// Returns the `Eth1Data` that should be included in a block being produced for the given
+    /// `state`.
+    fn eth1_data(&self, beacon_state: &BeaconState<T>) -> Result<Eth1Data>;
+
+    /// Returns all `Deposits` between `state.eth1_deposit_index` and
+    /// `state.eth1_data.deposit_count`.
+    ///
+    /// # Note:
+    ///
+    /// It is possible that not all returned `Deposits` can be included in a block. E.g., there may
+    /// be more than `MAX_DEPOSIT_COUNT` or the churn may be too high.
+    fn queued_deposits(&self, beacon_state: &BeaconState<T>) -> Result<Vec<Deposit>>;
+}
+
+pub struct InteropEth1ChainBackend<T: EthSpec> {
+    _phantom: PhantomData<T>,
+}
+
+impl<T: EthSpec> Eth1ChainBackend<T> for InteropEth1ChainBackend<T> {
+    fn new(_server: String) -> Result<Self> {
+        Ok(Self::default())
+    }
+
+    fn eth1_data(&self, state: &BeaconState<T>) -> Result<Eth1Data> {
+        let current_epoch = state.current_epoch();
+        let slots_per_voting_period = T::slots_per_eth1_voting_period() as u64;
+        let current_voting_period: u64 = current_epoch.as_u64() / slots_per_voting_period;
+
+        let deposit_root = hash(&int_to_bytes32(current_voting_period));
+        let block_hash = hash(&deposit_root);
+
+        Ok(Eth1Data {
+            deposit_root: Hash256::from_slice(&deposit_root),
+            deposit_count: state.eth1_deposit_index,
+            block_hash: Hash256::from_slice(&block_hash),
+        })
+    }
+
+    fn queued_deposits(&self, _: &BeaconState<T>) -> Result<Vec<Deposit>> {
+        Ok(vec![])
+    }
+}
+
+impl<T: EthSpec> Default for InteropEth1ChainBackend<T> {
+    fn default() -> Self {
+        Self {
+            _phantom: PhantomData,
+        }
+    }
+}
+
+/// Returns `int` as little-endian bytes with a length of 32.
+fn int_to_bytes32(int: u64) -> Vec<u8> {
+    let mut vec = int.to_le_bytes().to_vec();
+    vec.resize(32, 0);
+    vec
+}

beacon_node/beacon_chain/src/events.rs

@@ -0,0 +1,55 @@
+use serde_derive::{Deserialize, Serialize};
+use std::marker::PhantomData;
+use types::{Attestation, BeaconBlock, Epoch, EthSpec, Hash256};
+
+pub trait EventHandler<T: EthSpec>: Sized + Send + Sync {
+    fn register(&self, kind: EventKind<T>) -> Result<(), String>;
+}
+
+pub struct NullEventHandler<T: EthSpec>(PhantomData<T>);
+
+impl<T: EthSpec> EventHandler<T> for NullEventHandler<T> {
+    fn register(&self, _kind: EventKind<T>) -> Result<(), String> {
+        Ok(())
+    }
+}
+
+impl<T: EthSpec> Default for NullEventHandler<T> {
+    fn default() -> Self {
+        NullEventHandler(PhantomData)
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(
+    bound = "T: EthSpec",
+    rename_all = "snake_case",
+    tag = "event",
+    content = "data"
+)]
+pub enum EventKind<T: EthSpec> {
+    BeaconHeadChanged {
+        reorg: bool,
+        current_head_beacon_block_root: Hash256,
+        previous_head_beacon_block_root: Hash256,
+    },
+    BeaconFinalization {
+        epoch: Epoch,
+        root: Hash256,
+    },
+    BeaconBlockImported {
+        block_root: Hash256,
+        block: Box<BeaconBlock<T>>,
+    },
+    BeaconBlockRejected {
+        reason: String,
+        block: Box<BeaconBlock<T>>,
+    },
+    BeaconAttestationImported {
+        attestation: Box<Attestation<T>>,
+    },
+    BeaconAttestationRejected {
+        reason: String,
+        attestation: Box<Attestation<T>>,
+    },
+}

beacon_node/beacon_chain/src/fork_choice.rs

@@ -199,6 +199,14 @@ impl<T: BeaconChainTypes> ForkChoice<T> {
         self.backend.latest_message(validator_index)
     }
 
+    /// Runs an integrity verification function on the underlying fork choice algorithm.
+    ///
+    /// Returns `Ok(())` if the underlying fork choice has maintained it's integrity,
+    /// `Err(description)` otherwise.
+    pub fn verify_integrity(&self) -> core::result::Result<(), String> {
+        self.backend.verify_integrity()
+    }
+
     /// Inform the fork choice that the given block (and corresponding root) have been finalized so
     /// it may prune it's storage.
     ///

beacon_node/beacon_chain/src/lib.rs

@@ -3,8 +3,11 @@
 extern crate lazy_static;
 
 mod beacon_chain;
+mod beacon_chain_builder;
 mod checkpoint;
 mod errors;
+mod eth1_chain;
+pub mod events;
 mod fork_choice;
 mod iter;
 mod metrics;
@@ -16,6 +19,8 @@ pub use self::beacon_chain::{
 };
 pub use self::checkpoint::CheckPoint;
 pub use self::errors::{BeaconChainError, BlockProductionError};
+pub use beacon_chain_builder::BeaconChainBuilder;
+pub use eth1_chain::{Eth1ChainBackend, InteropEth1ChainBackend};
 pub use lmd_ghost;
 pub use metrics::scrape_for_metrics;
 pub use parking_lot;

beacon_node/beacon_chain/src/persisted_beacon_chain.rs

@@ -3,7 +3,7 @@ use operation_pool::PersistedOperationPool;
 use ssz::{Decode, Encode};
 use ssz_derive::{Decode, Encode};
 use store::{DBColumn, Error as StoreError, StoreItem};
-use types::{BeaconState, Hash256};
+use types::Hash256;
 
 /// 32-byte key for accessing the `PersistedBeaconChain`.
 pub const BEACON_CHAIN_DB_KEY: &str = "PERSISTEDBEACONCHAINPERSISTEDBEA";
@@ -13,7 +13,6 @@ pub struct PersistedBeaconChain<T: BeaconChainTypes> {
     pub canonical_head: CheckPoint<T::EthSpec>,
     pub op_pool: PersistedOperationPool<T::EthSpec>,
     pub genesis_block_root: Hash256,
-    pub state: BeaconState<T::EthSpec>,
 }
 
 impl<T: BeaconChainTypes> StoreItem for PersistedBeaconChain<T> {

beacon_node/beacon_chain/src/test_utils.rs

@@ -1,23 +1,28 @@
-use crate::{BeaconChain, BeaconChainTypes, BlockProcessingOutcome};
+use crate::{
+    events::NullEventHandler, AttestationProcessingOutcome, BeaconChain, BeaconChainBuilder,
+    BeaconChainTypes, BlockProcessingOutcome, InteropEth1ChainBackend,
+};
 use lmd_ghost::LmdGhost;
 use rayon::prelude::*;
-use sloggers::{null::NullLoggerBuilder, Build};
-use slot_clock::SlotClock;
+use sloggers::{terminal::TerminalLoggerBuilder, types::Severity, Build};
 use slot_clock::TestingSlotClock;
 use state_processing::per_slot_processing;
 use std::marker::PhantomData;
 use std::sync::Arc;
 use store::MemoryStore;
-use store::Store;
 use tree_hash::{SignedRoot, TreeHash};
 use types::{
-    test_utils::TestingBeaconStateBuilder, AggregateSignature, Attestation,
-    AttestationDataAndCustodyBit, BeaconBlock, BeaconState, BitList, ChainSpec, Domain, EthSpec,
-    Hash256, Keypair, RelativeEpoch, SecretKey, Signature, Slot,
+    AggregateSignature, Attestation, AttestationDataAndCustodyBit, BeaconBlock, BeaconState,
+    BitList, ChainSpec, Domain, EthSpec, Hash256, Keypair, RelativeEpoch, SecretKey, Signature,
+    Slot,
 };
 
+pub use types::test_utils::generate_deterministic_keypairs;
+
 pub use crate::persisted_beacon_chain::{PersistedBeaconChain, BEACON_CHAIN_DB_KEY};
 
+pub const HARNESS_GENESIS_TIME: u64 = 1567552690; // 4th September 2019
+
 /// Indicates how the `BeaconChainHarness` should produce blocks.
 #[derive(Clone, Copy, Debug)]
 pub enum BlockStrategy {
@@ -61,7 +66,9 @@ where
     type Store = MemoryStore;
     type SlotClock = TestingSlotClock;
     type LmdGhost = L;
+    type Eth1Chain = InteropEth1ChainBackend<E>;
     type EthSpec = E;
+    type EventHandler = NullEventHandler<E>;
 }
 
 /// A testing harness which can instantiate a `BeaconChain` and populate it with blocks and
@@ -84,53 +91,25 @@ where
     E: EthSpec,
 {
     /// Instantiate a new harness with `validator_count` initial validators.
-    pub fn new(validator_count: usize) -> Self {
-        let state_builder = TestingBeaconStateBuilder::from_default_keypairs_file_if_exists(
-            validator_count,
-            &E::default_spec(),
-        );
-        let (genesis_state, keypairs) = state_builder.build();
-
-        Self::from_state_and_keypairs(genesis_state, keypairs)
-    }
-
-    /// Instantiate a new harness with an initial validator for each key supplied.
-    pub fn from_keypairs(keypairs: Vec<Keypair>) -> Self {
-        let state_builder = TestingBeaconStateBuilder::from_keypairs(keypairs, &E::default_spec());
-        let (genesis_state, keypairs) = state_builder.build();
-
-        Self::from_state_and_keypairs(genesis_state, keypairs)
-    }
-
-    /// Instantiate a new harness with the given genesis state and a keypair for each of the
-    /// initial validators in the given state.
-    pub fn from_state_and_keypairs(genesis_state: BeaconState<E>, keypairs: Vec<Keypair>) -> Self {
+    pub fn new(keypairs: Vec<Keypair>) -> Self {
         let spec = E::default_spec();
 
+        let log = TerminalLoggerBuilder::new()
+            .level(Severity::Warning)
+            .build()
+            .expect("logger should build");
+
         let store = Arc::new(MemoryStore::open());
 
-        let mut genesis_block = BeaconBlock::empty(&spec);
-        genesis_block.state_root = Hash256::from_slice(&genesis_state.tree_hash_root());
-
-        let builder = NullLoggerBuilder;
-        let log = builder.build().expect("logger should build");
-
-        // Slot clock
-        let slot_clock = TestingSlotClock::new(
-            spec.genesis_slot,
-            genesis_state.genesis_time,
-            spec.seconds_per_slot,
-        );
-
-        let chain = BeaconChain::from_genesis(
-            store,
-            slot_clock,
-            genesis_state,
-            genesis_block,
-            spec.clone(),
-            log,
-        )
-        .expect("Terminate if beacon chain generation fails");
+        let chain =
+            BeaconChainBuilder::quick_start(HARNESS_GENESIS_TIME, &keypairs, spec.clone(), log)
+                .unwrap_or_else(|e| panic!("Failed to create beacon chain builder: {}", e))
+                .build(
+                    store.clone(),
+                    InteropEth1ChainBackend::default(),
+                    NullEventHandler::default(),
+                )
+                .unwrap_or_else(|e| panic!("Failed to build beacon chain: {}", e));
 
         Self {
             chain,
@@ -144,7 +123,6 @@ where
     /// Does not produce blocks or attestations.
     pub fn advance_slot(&self) {
         self.chain.slot_clock.advance_slot();
-        self.chain.catchup_state().expect("should catchup state");
     }
 
     /// Extend the `BeaconChain` with some blocks and attestations. Returns the root of the
@@ -166,26 +144,27 @@ where
             // Determine the slot for the first block (or skipped block).
             let state_slot = match block_strategy {
                 BlockStrategy::OnCanonicalHead => {
-                    self.chain.read_slot_clock().expect("should know slot") - 1
+                    self.chain.slot().expect("should have a slot") - 1
                 }
                 BlockStrategy::ForkCanonicalChainAt { previous_slot, .. } => previous_slot,
             };
 
-            self.get_state_at_slot(state_slot)
+            self.chain
+                .state_at_slot(state_slot)
+                .expect("should find state for slot")
+                .clone()
         };
 
         // Determine the first slot where a block should be built.
         let mut slot = match block_strategy {
-            BlockStrategy::OnCanonicalHead => {
-                self.chain.read_slot_clock().expect("should know slot")
-            }
+            BlockStrategy::OnCanonicalHead => self.chain.slot().expect("should have a slot"),
             BlockStrategy::ForkCanonicalChainAt { first_slot, .. } => first_slot,
         };
 
         let mut head_block_root = None;
 
         for _ in 0..num_blocks {
-            while self.chain.read_slot_clock().expect("should have a slot") < slot {
+            while self.chain.slot().expect("should have a slot") < slot {
                 self.advance_slot();
             }
 
@@ -211,21 +190,6 @@ where
         head_block_root.expect("did not produce any blocks")
     }
 
-    fn get_state_at_slot(&self, state_slot: Slot) -> BeaconState<E> {
-        let state_root = self
-            .chain
-            .rev_iter_state_roots()
-            .find(|(_hash, slot)| *slot == state_slot)
-            .map(|(hash, _slot)| hash)
-            .expect("could not find state root");
-
-        self.chain
-            .store
-            .get(&state_root)
-            .expect("should read db")
-            .expect("should find state root")
-    }
-
     /// Returns a newly created block, signed by the proposer for the given slot.
     fn build_block(
         &self,
@@ -299,9 +263,14 @@ where
         )
         .into_iter()
         .for_each(|attestation| {
-            self.chain
+            match self
+                .chain
                 .process_attestation(attestation)
-                .expect("should process attestation");
+                .expect("should not error during attestation processing")
+            {
+                AttestationProcessingOutcome::Processed => (),
+                other => panic!("did not successfully process attestation: {:?}", other),
+            }
         });
     }
 

beacon_node/beacon_chain/tests/tests.rs

@@ -3,11 +3,14 @@
 #[macro_use]
 extern crate lazy_static;
 
-use beacon_chain::test_utils::{
-    AttestationStrategy, BeaconChainHarness, BlockStrategy, CommonTypes, PersistedBeaconChain,
-    BEACON_CHAIN_DB_KEY,
-};
 use beacon_chain::AttestationProcessingOutcome;
+use beacon_chain::{
+    test_utils::{
+        AttestationStrategy, BeaconChainHarness, BlockStrategy, CommonTypes, PersistedBeaconChain,
+        BEACON_CHAIN_DB_KEY,
+    },
+    BlockProcessingOutcome,
+};
 use lmd_ghost::ThreadSafeReducedTree;
 use rand::Rng;
 use store::{MemoryStore, Store};
@@ -25,7 +28,7 @@ lazy_static! {
 type TestForkChoice = ThreadSafeReducedTree<MemoryStore, MinimalEthSpec>;
 
 fn get_harness(validator_count: usize) -> BeaconChainHarness<TestForkChoice, MinimalEthSpec> {
-    let harness = BeaconChainHarness::from_keypairs(KEYPAIRS[0..validator_count].to_vec());
+    let harness = BeaconChainHarness::new(KEYPAIRS[0..validator_count].to_vec());
 
     harness.advance_slot();
 
@@ -322,7 +325,9 @@ fn roundtrip_operation_pool() {
     let p: PersistedBeaconChain<CommonTypes<TestForkChoice, MinimalEthSpec>> =
         harness.chain.store.get(&key).unwrap().unwrap();
 
-    let restored_op_pool = p.op_pool.into_operation_pool(&p.state, &harness.spec);
+    let restored_op_pool = p
+        .op_pool
+        .into_operation_pool(&p.canonical_head.beacon_state, &harness.spec);
 
     assert_eq!(harness.chain.op_pool, restored_op_pool);
 }
@@ -459,3 +464,48 @@ fn free_attestations_added_to_fork_choice_all_updated() {
         }
     }
 }
+
+fn run_skip_slot_test(skip_slots: u64) {
+    let num_validators = 8;
+    let harness_a = get_harness(num_validators);
+    let harness_b = get_harness(num_validators);
+
+    for _ in 0..skip_slots {
+        harness_a.advance_slot();
+        harness_b.advance_slot();
+    }
+
+    harness_a.extend_chain(
+        1,
+        BlockStrategy::OnCanonicalHead,
+        // No attestation required for test.
+        AttestationStrategy::SomeValidators(vec![]),
+    );
+
+    assert_eq!(
+        harness_a.chain.head().beacon_block.slot,
+        Slot::new(skip_slots + 1)
+    );
+    assert_eq!(harness_b.chain.head().beacon_block.slot, Slot::new(0));
+
+    assert_eq!(
+        harness_b
+            .chain
+            .process_block(harness_a.chain.head().beacon_block.clone()),
+        Ok(BlockProcessingOutcome::Processed {
+            block_root: harness_a.chain.head().beacon_block_root
+        })
+    );
+
+    assert_eq!(
+        harness_b.chain.head().beacon_block.slot,
+        Slot::new(skip_slots + 1)
+    );
+}
+
+#[test]
+fn produces_and_processes_with_genesis_skip_slots() {
+    for i in 0..MinimalEthSpec::slots_per_epoch() * 4 {
+        run_skip_slot_test(i)
+    }
+}

beacon_node/client/Cargo.toml

@@ -6,10 +6,12 @@ edition = "2018"
 
 [dependencies]
 beacon_chain = { path = "../beacon_chain" }
+store = { path = "../store" }
 network = { path = "../network" }
 eth2-libp2p = { path = "../eth2-libp2p" }
 rpc = { path = "../rpc" }
 rest_api = { path = "../rest_api" }
+websocket_server = { path = "../websocket_server" }
 prometheus = "^0.6"
 types = { path = "../../eth2/types" }
 tree_hash = "0.1"

beacon_node/client/src/beacon_chain_types.rs

@@ -1,169 +0,0 @@
-use crate::bootstrapper::Bootstrapper;
-use crate::error::Result;
-use crate::{config::GenesisState, ClientConfig};
-use beacon_chain::{
-    lmd_ghost::{LmdGhost, ThreadSafeReducedTree},
-    slot_clock::SystemTimeSlotClock,
-    store::Store,
-    BeaconChain, BeaconChainTypes,
-};
-use slog::{crit, info, Logger};
-use slot_clock::SlotClock;
-use std::fs::File;
-use std::marker::PhantomData;
-use std::sync::Arc;
-use std::time::SystemTime;
-use tree_hash::TreeHash;
-use types::{
-    test_utils::TestingBeaconStateBuilder, BeaconBlock, BeaconState, ChainSpec, EthSpec, Hash256,
-};
-
-/// Provides a new, initialized `BeaconChain`
-pub trait InitialiseBeaconChain<T: BeaconChainTypes> {
-    fn initialise_beacon_chain(
-        store: Arc<T::Store>,
-        config: &ClientConfig,
-        spec: ChainSpec,
-        log: Logger,
-    ) -> Result<BeaconChain<T>> {
-        maybe_load_from_store_for_testnet::<_, T::Store, T::EthSpec>(store, config, spec, log)
-    }
-}
-
-#[derive(Clone)]
-pub struct ClientType<S: Store, E: EthSpec> {
-    _phantom_t: PhantomData<S>,
-    _phantom_u: PhantomData<E>,
-}
-
-impl<S, E> BeaconChainTypes for ClientType<S, E>
-where
-    S: Store + 'static,
-    E: EthSpec,
-{
-    type Store = S;
-    type SlotClock = SystemTimeSlotClock;
-    type LmdGhost = ThreadSafeReducedTree<S, E>;
-    type EthSpec = E;
-}
-impl<T: Store, E: EthSpec, X: BeaconChainTypes> InitialiseBeaconChain<X> for ClientType<T, E> {}
-
-/// Loads a `BeaconChain` from `store`, if it exists. Otherwise, create a new chain from genesis.
-fn maybe_load_from_store_for_testnet<T, U: Store, V: EthSpec>(
-    store: Arc<U>,
-    config: &ClientConfig,
-    spec: ChainSpec,
-    log: Logger,
-) -> Result<BeaconChain<T>>
-where
-    T: BeaconChainTypes<Store = U, EthSpec = V>,
-    T::LmdGhost: LmdGhost<U, V>,
-{
-    let genesis_state = match &config.genesis_state {
-        GenesisState::Mainnet => {
-            crit!(log, "This release does not support mainnet genesis state.");
-            return Err("Mainnet is unsupported".into());
-        }
-        GenesisState::RecentGenesis { validator_count } => {
-            generate_testnet_genesis_state(*validator_count, recent_genesis_time(), &spec)
-        }
-        GenesisState::Generated {
-            validator_count,
-            genesis_time,
-        } => generate_testnet_genesis_state(*validator_count, *genesis_time, &spec),
-        GenesisState::Yaml { file } => {
-            let file = File::open(file).map_err(|e| {
-                format!("Unable to open YAML genesis state file {:?}: {:?}", file, e)
-            })?;
-
-            serde_yaml::from_reader(file)
-                .map_err(|e| format!("Unable to parse YAML genesis state file: {:?}", e))?
-        }
-        GenesisState::HttpBootstrap { server } => {
-            let bootstrapper = Bootstrapper::from_server_string(server.to_string())
-                .map_err(|e| format!("Failed to initialize bootstrap client: {}", e))?;
-
-            let (state, _block) = bootstrapper
-                .genesis()
-                .map_err(|e| format!("Failed to bootstrap genesis state: {}", e))?;
-
-            state
-        }
-    };
-
-    let mut genesis_block = BeaconBlock::empty(&spec);
-    genesis_block.state_root = Hash256::from_slice(&genesis_state.tree_hash_root());
-    let genesis_block_root = genesis_block.canonical_root();
-
-    // Slot clock
-    let slot_clock = T::SlotClock::new(
-        spec.genesis_slot,
-        genesis_state.genesis_time,
-        spec.seconds_per_slot,
-    );
-
-    // Try load an existing `BeaconChain` from the store. If unable, create a new one.
-    if let Ok(Some(beacon_chain)) =
-        BeaconChain::from_store(store.clone(), spec.clone(), log.clone())
-    {
-        // Here we check to ensure that the `BeaconChain` loaded from store has the expected
-        // genesis block.
-        //
-        // Without this check, it's possible that there will be an existing DB with a `BeaconChain`
-        // that has different parameters than provided to this executable.
-        if beacon_chain.genesis_block_root == genesis_block_root {
-            info!(
-                log,
-                "Loaded BeaconChain from store";
-                "slot" => beacon_chain.head().beacon_state.slot,
-                "best_slot" => beacon_chain.best_slot(),
-            );
-
-            Ok(beacon_chain)
-        } else {
-            crit!(
-                log,
-                "The BeaconChain loaded from disk has an incorrect genesis root. \
-                 This may be caused by an old database in located in datadir."
-            );
-            Err("Incorrect genesis root".into())
-        }
-    } else {
-        BeaconChain::from_genesis(
-            store,
-            slot_clock,
-            genesis_state,
-            genesis_block,
-            spec,
-            log.clone(),
-        )
-        .map_err(|e| format!("Failed to initialize new beacon chain: {:?}", e).into())
-    }
-}
-
-fn generate_testnet_genesis_state<E: EthSpec>(
-    validator_count: usize,
-    genesis_time: u64,
-    spec: &ChainSpec,
-) -> BeaconState<E> {
-    let (mut genesis_state, _keypairs) =
-        TestingBeaconStateBuilder::from_default_keypairs_file_if_exists(validator_count, spec)
-            .build();
-
-    genesis_state.genesis_time = genesis_time;
-
-    genesis_state
-}
-
-/// Returns the system time, mod 30 minutes.
-///
-/// Used for easily creating testnets.
-fn recent_genesis_time() -> u64 {
-    let now = SystemTime::now()
-        .duration_since(SystemTime::UNIX_EPOCH)
-        .unwrap()
-        .as_secs();
-    let secs_after_last_period = now.checked_rem(30 * 60).unwrap_or(0);
-    // genesis is now the last 30 minute block.
-    now - secs_after_last_period
-}

beacon_node/client/src/config.rs

@@ -1,15 +1,11 @@
-use crate::{Bootstrapper, Eth2Config};
 use clap::ArgMatches;
 use network::NetworkConfig;
 use serde_derive::{Deserialize, Serialize};
-use slog::{info, o, warn, Drain};
+use slog::{info, o, Drain};
 use std::fs::{self, OpenOptions};
 use std::path::PathBuf;
 use std::sync::Mutex;
 
-/// The number initial validators when starting the `Minimal`.
-const TESTNET_VALIDATOR_COUNT: usize = 16;
-
 /// The number initial validators when starting the `Minimal`.
 const TESTNET_SPEC_CONSTANTS: &str = "minimal";
 
@@ -21,33 +17,74 @@ pub struct Config {
     db_name: String,
     pub log_file: PathBuf,
     pub spec_constants: String,
-    pub genesis_state: GenesisState,
+    /// Defines how we should initialize a BeaconChain instances.
+    ///
+    /// This field is not serialized, there for it will not be written to (or loaded from) config
+    /// files. It can only be configured via the CLI.
+    #[serde(skip)]
+    pub beacon_chain_start_method: BeaconChainStartMethod,
+    pub eth1_backend_method: Eth1BackendMethod,
     pub network: network::NetworkConfig,
     pub rpc: rpc::RPCConfig,
     pub rest_api: rest_api::ApiConfig,
+    pub websocket_server: websocket_server::Config,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
-#[serde(tag = "type")]
-pub enum GenesisState {
-    /// Use the mainnet genesis state.
-    ///
-    /// Mainnet genesis state is not presently known, so this is a place-holder.
+/// Defines how the client should initialize a BeaconChain.
+///
+/// In general, there are two methods:
+///  - resuming a new chain, or
+///  - initializing a new one.
+#[derive(Debug, Clone)]
+pub enum BeaconChainStartMethod {
+    /// Resume from an existing BeaconChain, loaded from the existing local database.
+    Resume,
+    /// Resume from an existing BeaconChain, loaded from the existing local database.
     Mainnet,
-    /// Generate a state with `validator_count` validators, all with well-known secret keys.
+    /// Create a new beacon chain that can connect to mainnet.
     ///
     /// Set the genesis time to be the start of the previous 30-minute window.
-    RecentGenesis { validator_count: usize },
-    /// Generate a state with `genesis_time` and `validator_count` validators, all with well-known
+    RecentGenesis {
+        validator_count: usize,
+        minutes: u64,
+    },
+    /// Create a new beacon chain with `genesis_time` and `validator_count` validators, all with well-known
     /// secret keys.
     Generated {
         validator_count: usize,
         genesis_time: u64,
     },
-    /// Load a YAML-encoded genesis state from a file.
+    /// Create a new beacon chain by loading a YAML-encoded genesis state from a file.
     Yaml { file: PathBuf },
-    /// Use a HTTP server (running our REST-API) to load genesis and finalized states and blocks.
-    HttpBootstrap { server: String },
+    /// Create a new beacon chain by loading a SSZ-encoded genesis state from a file.
+    Ssz { file: PathBuf },
+    /// Create a new beacon chain by loading a JSON-encoded genesis state from a file.
+    Json { file: PathBuf },
+    /// Create a new beacon chain by using a HTTP server (running our REST-API) to load genesis and
+    /// finalized states and blocks.
+    HttpBootstrap { server: String, port: Option<u16> },
+}
+
+impl Default for BeaconChainStartMethod {
+    fn default() -> Self {
+        BeaconChainStartMethod::Resume
+    }
+}
+
+/// Defines which Eth1 backend the client should use.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "type")]
+pub enum Eth1BackendMethod {
+    /// Use the mocked eth1 backend used in interop testing
+    Interop,
+    /// Use a web3 connection to a running Eth1 node.
+    Web3 { server: String },
+}
+
+impl Default for Eth1BackendMethod {
+    fn default() -> Self {
+        Eth1BackendMethod::Interop
+    }
 }
 
 impl Default for Config {
@@ -58,12 +95,12 @@ impl Default for Config {
             db_type: "disk".to_string(),
             db_name: "chain_db".to_string(),
             network: NetworkConfig::new(),
-            rpc: rpc::RPCConfig::default(),
-            rest_api: rest_api::ApiConfig::default(),
+            rpc: <_>::default(),
+            rest_api: <_>::default(),
+            websocket_server: <_>::default(),
             spec_constants: TESTNET_SPEC_CONSTANTS.into(),
-            genesis_state: GenesisState::RecentGenesis {
-                validator_count: TESTNET_VALIDATOR_COUNT,
-            },
+            beacon_chain_start_method: <_>::default(),
+            eth1_backend_method: <_>::default(),
         }
     }
 }
@@ -76,6 +113,8 @@ impl Config {
     }
 
     /// Returns the core path for the client.
+    ///
+    /// Creates the directory if it does not exist.
     pub fn data_dir(&self) -> Option<PathBuf> {
         let path = dirs::home_dir()?.join(&self.data_dir);
         fs::create_dir_all(&path).ok()?;
@@ -127,15 +166,6 @@ impl Config {
             self.data_dir = PathBuf::from(dir);
         };
 
-        if let Some(default_spec) = args.value_of("default-spec") {
-            match default_spec {
-                "mainnet" => self.spec_constants = Eth2Config::mainnet().spec_constants,
-                "minimal" => self.spec_constants = Eth2Config::minimal().spec_constants,
-                "interop" => self.spec_constants = Eth2Config::interop().spec_constants,
-                _ => {} // not supported
-            }
-        }
-
         if let Some(dir) = args.value_of("db") {
             self.db_type = dir.to_string();
         };
@@ -143,46 +173,13 @@ impl Config {
         self.network.apply_cli_args(args)?;
         self.rpc.apply_cli_args(args)?;
         self.rest_api.apply_cli_args(args)?;
+        self.websocket_server.apply_cli_args(args)?;
 
         if let Some(log_file) = args.value_of("logfile") {
             self.log_file = PathBuf::from(log_file);
             self.update_logger(log)?;
         };
 
-        // If the `--bootstrap` flag is provided, overwrite the default configuration.
-        if let Some(server) = args.value_of("bootstrap") {
-            do_bootstrapping(self, server.to_string(), &log)?;
-        }
-
         Ok(())
     }
 }
-
-/// Perform the HTTP bootstrapping procedure, reading an ENR and multiaddr from the HTTP server and
-/// adding them to the `config`.
-fn do_bootstrapping(config: &mut Config, server: String, log: &slog::Logger) -> Result<(), String> {
-    // Set the genesis state source.
-    config.genesis_state = GenesisState::HttpBootstrap {
-        server: server.to_string(),
-    };
-
-    let bootstrapper = Bootstrapper::from_server_string(server.to_string())?;
-
-    config.network.boot_nodes.push(bootstrapper.enr()?);
-
-    if let Some(server_multiaddr) = bootstrapper.best_effort_multiaddr() {
-        info!(
-            log,
-            "Estimated bootstrapper libp2p address";
-            "multiaddr" => format!("{:?}", server_multiaddr)
-        );
-        config.network.libp2p_nodes.push(server_multiaddr);
-    } else {
-        warn!(
-            log,
-            "Unable to estimate a bootstrapper libp2p address, this node may not find any peers."
-        );
-    }
-
-    Ok(())
-}

beacon_node/client/src/lib.rs

@@ -1,97 +1,216 @@
 extern crate slog;
 
-mod beacon_chain_types;
-mod bootstrapper;
 mod config;
 
 pub mod error;
 pub mod notifier;
 
-use beacon_chain::BeaconChain;
+use beacon_chain::{
+    lmd_ghost::ThreadSafeReducedTree, slot_clock::SystemTimeSlotClock, store::Store,
+    test_utils::generate_deterministic_keypairs, BeaconChain, BeaconChainBuilder,
+};
 use exit_future::Signal;
 use futures::{future::Future, Stream};
 use network::Service as NetworkService;
-use slog::{error, info, o};
+use slog::{crit, error, info, o};
 use slot_clock::SlotClock;
 use std::marker::PhantomData;
 use std::sync::Arc;
-use std::time::{Duration, Instant};
+use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
 use tokio::runtime::TaskExecutor;
 use tokio::timer::Interval;
+use types::EthSpec;
+use websocket_server::WebSocketSender;
 
-pub use beacon_chain::BeaconChainTypes;
-pub use beacon_chain_types::ClientType;
-pub use beacon_chain_types::InitialiseBeaconChain;
-pub use bootstrapper::Bootstrapper;
-pub use config::{Config as ClientConfig, GenesisState};
+pub use beacon_chain::{BeaconChainTypes, Eth1ChainBackend, InteropEth1ChainBackend};
+pub use config::{BeaconChainStartMethod, Config as ClientConfig, Eth1BackendMethod};
 pub use eth2_config::Eth2Config;
 
+#[derive(Clone)]
+pub struct RuntimeBeaconChainTypes<S: Store, E: EthSpec> {
+    _phantom_s: PhantomData<S>,
+    _phantom_e: PhantomData<E>,
+}
+
+impl<S, E> BeaconChainTypes for RuntimeBeaconChainTypes<S, E>
+where
+    S: Store + 'static,
+    E: EthSpec,
+{
+    type Store = S;
+    type SlotClock = SystemTimeSlotClock;
+    type LmdGhost = ThreadSafeReducedTree<S, E>;
+    type Eth1Chain = InteropEth1ChainBackend<E>;
+    type EthSpec = E;
+    type EventHandler = WebSocketSender<E>;
+}
+
 /// Main beacon node client service. This provides the connection and initialisation of the clients
 /// sub-services in multiple threads.
-pub struct Client<T: BeaconChainTypes> {
+pub struct Client<S, E>
+where
+    S: Store + Clone + 'static,
+    E: EthSpec,
+{
     /// Configuration for the lighthouse client.
     _client_config: ClientConfig,
     /// The beacon chain for the running client.
-    beacon_chain: Arc<BeaconChain<T>>,
+    beacon_chain: Arc<BeaconChain<RuntimeBeaconChainTypes<S, E>>>,
     /// Reference to the network service.
-    pub network: Arc<NetworkService<T>>,
+    pub network: Arc<NetworkService<RuntimeBeaconChainTypes<S, E>>>,
     /// Signal to terminate the RPC server.
     pub rpc_exit_signal: Option<Signal>,
     /// Signal to terminate the slot timer.
     pub slot_timer_exit_signal: Option<Signal>,
     /// Signal to terminate the API
     pub api_exit_signal: Option<Signal>,
+    /// Signal to terminate the websocket server
+    pub websocket_exit_signal: Option<Signal>,
     /// The clients logger.
     log: slog::Logger,
-    /// Marker to pin the beacon chain generics.
-    phantom: PhantomData<T>,
 }
 
-impl<T> Client<T>
+impl<S, E> Client<S, E>
 where
-    T: BeaconChainTypes + InitialiseBeaconChain<T> + Clone,
+    S: Store + Clone + 'static,
+    E: EthSpec,
 {
     /// Generate an instance of the client. Spawn and link all internal sub-processes.
     pub fn new(
         client_config: ClientConfig,
         eth2_config: Eth2Config,
-        store: T::Store,
+        store: S,
         log: slog::Logger,
         executor: &TaskExecutor,
     ) -> error::Result<Self> {
         let store = Arc::new(store);
-        let seconds_per_slot = eth2_config.spec.seconds_per_slot;
+        let milliseconds_per_slot = eth2_config.spec.milliseconds_per_slot;
 
-        // Load a `BeaconChain` from the store, or create a new one if it does not exist.
-        let beacon_chain = Arc::new(T::initialise_beacon_chain(
-            store,
-            &client_config,
-            eth2_config.spec.clone(),
-            log.clone(),
-        )?);
+        let spec = &eth2_config.spec.clone();
 
-        if beacon_chain.read_slot_clock().is_none() {
-            panic!("Cannot start client before genesis!")
-        }
+        let beacon_chain_builder = match &client_config.beacon_chain_start_method {
+            BeaconChainStartMethod::Resume => {
+                info!(
+                    log,
+                    "Starting beacon chain";
+                    "method" => "resume"
+                );
+                BeaconChainBuilder::from_store(spec.clone(), log.clone())
+            }
+            BeaconChainStartMethod::Mainnet => {
+                crit!(log, "No mainnet beacon chain startup specification.");
+                return Err("Mainnet launch is not yet announced.".into());
+            }
+            BeaconChainStartMethod::RecentGenesis {
+                validator_count,
+                minutes,
+            } => {
+                info!(
+                    log,
+                    "Starting beacon chain";
+                    "validator_count" => validator_count,
+                    "minutes" => minutes,
+                    "method" => "recent"
+                );
+                BeaconChainBuilder::recent_genesis(
+                    &generate_deterministic_keypairs(*validator_count),
+                    *minutes,
+                    spec.clone(),
+                    log.clone(),
+                )?
+            }
+            BeaconChainStartMethod::Generated {
+                validator_count,
+                genesis_time,
+            } => {
+                info!(
+                    log,
+                    "Starting beacon chain";
+                    "validator_count" => validator_count,
+                    "genesis_time" => genesis_time,
+                    "method" => "quick"
+                );
+                BeaconChainBuilder::quick_start(
+                    *genesis_time,
+                    &generate_deterministic_keypairs(*validator_count),
+                    spec.clone(),
+                    log.clone(),
+                )?
+            }
+            BeaconChainStartMethod::Yaml { file } => {
+                info!(
+                    log,
+                    "Starting beacon chain";
+                    "file" => format!("{:?}", file),
+                    "method" => "yaml"
+                );
+                BeaconChainBuilder::yaml_state(file, spec.clone(), log.clone())?
+            }
+            BeaconChainStartMethod::Ssz { file } => {
+                info!(
+                    log,
+                    "Starting beacon chain";
+                    "file" => format!("{:?}", file),
+                    "method" => "ssz"
+                );
+                BeaconChainBuilder::ssz_state(file, spec.clone(), log.clone())?
+            }
+            BeaconChainStartMethod::Json { file } => {
+                info!(
+                    log,
+                    "Starting beacon chain";
+                    "file" => format!("{:?}", file),
+                    "method" => "json"
+                );
+                BeaconChainBuilder::json_state(file, spec.clone(), log.clone())?
+            }
+            BeaconChainStartMethod::HttpBootstrap { server, port } => {
+                info!(
+                    log,
+                    "Starting beacon chain";
+                    "port" => port,
+                    "server" => server,
+                    "method" => "bootstrap"
+                );
+                BeaconChainBuilder::http_bootstrap(server, spec.clone(), log.clone())?
+            }
+        };
 
-        // Block starting the client until we have caught the state up to the current slot.
-        //
-        // If we don't block here we create an initial scenario where we're unable to process any
-        // blocks and we're basically useless.
-        {
-            let state_slot = beacon_chain.head().beacon_state.slot;
-            let wall_clock_slot = beacon_chain.read_slot_clock().unwrap();
-            let slots_since_genesis = beacon_chain.slots_since_genesis().unwrap();
+        let eth1_backend =
+            InteropEth1ChainBackend::new(String::new()).map_err(|e| format!("{:?}", e))?;
+
+        // Start the websocket server.
+        let (websocket_sender, websocket_exit_signal): (WebSocketSender<E>, Option<_>) =
+            if client_config.websocket_server.enabled {
+                let (sender, exit) = websocket_server::start_server(
+                    &client_config.websocket_server,
+                    executor,
+                    &log,
+                )?;
+                (sender, Some(exit))
+            } else {
+                (WebSocketSender::dummy(), None)
+            };
+
+        let beacon_chain: Arc<BeaconChain<RuntimeBeaconChainTypes<S, E>>> = Arc::new(
+            beacon_chain_builder
+                .build(store, eth1_backend, websocket_sender)
+                .map_err(error::Error::from)?,
+        );
+
+        let since_epoch = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .map_err(|e| format!("Unable to read system time: {}", e))?;
+        let since_genesis = Duration::from_secs(beacon_chain.head().beacon_state.genesis_time);
+
+        if since_genesis > since_epoch {
             info!(
                 log,
-                "BeaconState cache init";
-                "state_slot" => state_slot,
-                "wall_clock_slot" => wall_clock_slot,
-                "slots_since_genesis" => slots_since_genesis,
-                "catchup_distance" => wall_clock_slot - state_slot,
+                "Starting node prior to genesis";
+                "now" => since_epoch.as_secs(),
+                "genesis_seconds" => since_genesis.as_secs(),
             );
         }
-        do_state_catchup(&beacon_chain, &log);
 
         let network_config = &client_config.network;
         let (network, network_send) =
@@ -117,7 +236,9 @@ where
                 executor,
                 beacon_chain.clone(),
                 network.clone(),
+                network_send.clone(),
                 client_config.db_path().expect("unable to read datadir"),
+                eth2_config.clone(),
                 &log,
             ) {
                 Ok(s) => Some(s),
@@ -131,11 +252,11 @@ where
         };
 
         let (slot_timer_exit_signal, exit) = exit_future::signal();
-        if let Ok(Some(duration_to_next_slot)) = beacon_chain.slot_clock.duration_to_next_slot() {
+        if let Some(duration_to_next_slot) = beacon_chain.slot_clock.duration_to_next_slot() {
             // set up the validator work interval - start at next slot and proceed every slot
             let interval = {
                 // Set the interval to start at the next slot, and every slot after
-                let slot_duration = Duration::from_secs(seconds_per_slot);
+                let slot_duration = Duration::from_millis(milliseconds_per_slot);
                 //TODO: Handle checked add correctly
                 Interval::new(Instant::now() + duration_to_next_slot, slot_duration)
             };
@@ -146,7 +267,7 @@ where
                 exit.until(
                     interval
                         .for_each(move |_| {
-                            do_state_catchup(&chain, &log);
+                            log_new_slot(&chain, &log);
 
                             Ok(())
                         })
@@ -162,49 +283,33 @@ where
             rpc_exit_signal,
             slot_timer_exit_signal: Some(slot_timer_exit_signal),
             api_exit_signal,
+            websocket_exit_signal,
             log,
             network,
-            phantom: PhantomData,
         })
     }
 }
 
-impl<T: BeaconChainTypes> Drop for Client<T> {
+impl<S: Store + Clone, E: EthSpec> Drop for Client<S, E> {
     fn drop(&mut self) {
         // Save the beacon chain to it's store before dropping.
         let _result = self.beacon_chain.persist();
     }
 }
 
-fn do_state_catchup<T: BeaconChainTypes>(chain: &Arc<BeaconChain<T>>, log: &slog::Logger) {
-    // Only attempt to `catchup_state` if we can read the slot clock.
-    if let Some(current_slot) = chain.read_slot_clock() {
-        let state_catchup_result = chain.catchup_state();
+fn log_new_slot<T: BeaconChainTypes>(chain: &Arc<BeaconChain<T>>, log: &slog::Logger) {
+    let best_slot = chain.head().beacon_block.slot;
+    let latest_block_root = chain.head().beacon_block_root;
 
-        let best_slot = chain.head().beacon_block.slot;
-        let latest_block_root = chain.head().beacon_block_root;
-
-        let common = o!(
+    if let Ok(current_slot) = chain.slot() {
+        info!(
+            log,
+            "Slot start";
             "skip_slots" => current_slot.saturating_sub(best_slot),
             "best_block_root" => format!("{}", latest_block_root),
             "best_block_slot" => best_slot,
             "slot" => current_slot,
-        );
-
-        if let Err(e) = state_catchup_result {
-            error!(
-                log,
-                "State catchup failed";
-                "error" => format!("{:?}", e),
-                common
-            )
-        } else {
-            info!(
-                log,
-                "Slot start";
-                common
-            )
-        }
+        )
     } else {
         error!(
             log,

beacon_node/client/src/notifier.rs

@@ -1,11 +1,12 @@
 use crate::Client;
-use beacon_chain::BeaconChainTypes;
 use exit_future::Exit;
 use futures::{Future, Stream};
 use slog::{debug, o, warn};
 use std::time::{Duration, Instant};
+use store::Store;
 use tokio::runtime::TaskExecutor;
 use tokio::timer::Interval;
+use types::EthSpec;
 
 /// The interval between heartbeat events.
 pub const HEARTBEAT_INTERVAL_SECONDS: u64 = 15;
@@ -17,7 +18,11 @@ pub const WARN_PEER_COUNT: usize = 1;
 /// durations.
 ///
 /// Presently unused, but remains for future use.
-pub fn run<T: BeaconChainTypes>(client: &Client<T>, executor: TaskExecutor, exit: Exit) {
+pub fn run<S, E>(client: &Client<S, E>, executor: TaskExecutor, exit: Exit)
+where
+    S: Store + Clone + 'static,
+    E: EthSpec,
+{
     // notification heartbeat
     let interval = Interval::new(
         Instant::now(),
@@ -34,10 +39,10 @@ pub fn run<T: BeaconChainTypes>(client: &Client<T>, executor: TaskExecutor, exit
         // Panics if libp2p is poisoned.
         let connected_peer_count = libp2p.lock().swarm.connected_peers();
 
-        debug!(log, "Libp2p connected peer status"; "peer_count" => connected_peer_count);
+        debug!(log, "Connected peer status"; "peer_count" => connected_peer_count);
 
         if connected_peer_count <= WARN_PEER_COUNT {
-            warn!(log, "Low libp2p peer count"; "peer_count" => connected_peer_count);
+            warn!(log, "Low peer count"; "peer_count" => connected_peer_count);
         }
 
         Ok(())

beacon_node/eth2-libp2p/Cargo.toml

@@ -6,9 +6,10 @@ edition = "2018"
 
 [dependencies]
 clap = "2.32.0"
+hex = "0.3"
 #SigP repository 
-libp2p =  { git = "https://github.com/SigP/rust-libp2p", rev = "61036890d574f5b46573952b20def2baafd6a6e9" }
-enr =  { git = "https://github.com/SigP/rust-libp2p/", rev = "61036890d574f5b46573952b20def2baafd6a6e9", features = ["serde"] }
+libp2p =  { git = "https://github.com/SigP/rust-libp2p", rev = "8ac9c744197faaadc0e2b64fed7470ac4e2a41ca" }
+enr =  { git = "https://github.com/SigP/rust-libp2p/", rev = "8ac9c744197faaadc0e2b64fed7470ac4e2a41ca", features = ["serde"] }
 types = { path =  "../../eth2/types" }
 serde = "1.0"
 serde_derive = "1.0"

beacon_node/eth2-libp2p/src/behaviour.rs

@@ -15,7 +15,7 @@ use libp2p::{
     tokio_io::{AsyncRead, AsyncWrite},
     NetworkBehaviour, PeerId,
 };
-use slog::{debug, o, trace};
+use slog::{debug, o};
 use std::num::NonZeroU32;
 use std::time::Duration;
 
@@ -90,13 +90,15 @@ impl<TSubstream: AsyncRead + AsyncWrite> NetworkBehaviourEventProcess<GossipsubE
 {
     fn inject_event(&mut self, event: GossipsubEvent) {
         match event {
-            GossipsubEvent::Message(gs_msg) => {
-                trace!(self.log, "Received GossipEvent");
-
+            GossipsubEvent::Message(propagation_source, gs_msg) => {
+                let id = gs_msg.id();
                 let msg = PubsubMessage::from_topics(&gs_msg.topics, gs_msg.data);
 
+                // Note: We are keeping track here of the peer that sent us the message, not the
+                // peer that originally published the message.
                 self.events.push(BehaviourEvent::GossipMessage {
-                    source: gs_msg.source,
+                    id,
+                    source: propagation_source,
                     topics: gs_msg.topics,
                     message: msg,
                 });
@@ -199,6 +201,13 @@ impl<TSubstream: AsyncRead + AsyncWrite> Behaviour<TSubstream> {
         }
     }
 
+    /// Forwards a message that is waiting in gossipsub's mcache. Messages are only propagated
+    /// once validated by the beacon chain.
+    pub fn propagate_message(&mut self, propagation_source: &PeerId, message_id: String) {
+        self.gossipsub
+            .propagate_message(&message_id, propagation_source);
+    }
+
     /* Eth2 RPC behaviour functions */
 
     /// Sends an RPC Request/Response via the RPC protocol.
@@ -214,12 +223,21 @@ impl<TSubstream: AsyncRead + AsyncWrite> Behaviour<TSubstream> {
 
 /// The types of events than can be obtained from polling the behaviour.
 pub enum BehaviourEvent {
+    /// A received RPC event and the peer that it was received from.
     RPC(PeerId, RPCEvent),
+    /// We have completed an initial connection to a new peer.
     PeerDialed(PeerId),
+    /// A peer has disconnected.
     PeerDisconnected(PeerId),
+    /// A gossipsub message has been received.
     GossipMessage {
+        /// The gossipsub message id. Used when propagating blocks after validation.
+        id: String,
+        /// The peer from which we received this message, not the peer that published it.
         source: PeerId,
+        /// The topics that this message was sent on.
         topics: Vec<TopicHash>,
+        /// The message itself.
         message: PubsubMessage,
     },
 }

beacon_node/eth2-libp2p/src/config.rs

@@ -40,6 +40,12 @@ pub struct Config {
     /// Target number of connected peers.
     pub max_peers: usize,
 
+    /// A secp256k1 secret key, as bytes in ASCII-encoded hex.
+    ///
+    /// With or without `0x` prefix.
+    #[serde(skip)]
+    pub secret_key_hex: Option<String>,
+
     /// Gossipsub configuration parameters.
     #[serde(skip)]
     pub gs_config: GossipsubConfig,
@@ -70,11 +76,13 @@ impl Default for Config {
             discovery_address: "127.0.0.1".parse().expect("valid ip address"),
             discovery_port: 9000,
             max_peers: 10,
+            secret_key_hex: None,
             // Note: The topics by default are sent as plain strings. Hashes are an optional
             // parameter.
             gs_config: GossipsubConfigBuilder::new()
                 .max_transmit_size(1_048_576)
-                .heartbeat_interval(Duration::from_secs(20))
+                .heartbeat_interval(Duration::from_secs(20)) // TODO: Reduce for mainnet
+                .propagate_messages(false) // require validation before propagation
                 .build(),
             boot_nodes: vec![],
             libp2p_nodes: vec![],
@@ -157,6 +165,10 @@ impl Config {
                 .map_err(|_| format!("Invalid discovery port: {}", disc_port_str))?;
         }
 
+        if let Some(p2p_priv_key) = args.value_of("p2p-priv-key") {
+            self.secret_key_hex = Some(p2p_priv_key.to_string());
+        }
+
         Ok(())
     }
 }

beacon_node/eth2-libp2p/src/discovery.rs

@@ -114,7 +114,7 @@ impl<TSubstream> Discovery<TSubstream> {
         self.find_peers();
     }
 
-    /// Add an Enr to the routing table of the discovery mechanism.
+    /// Add an ENR to the routing table of the discovery mechanism.
     pub fn add_enr(&mut self, enr: Enr) {
         self.discovery.add_enr(enr);
     }
@@ -169,6 +169,7 @@ where
 
     fn inject_connected(&mut self, peer_id: PeerId, _endpoint: ConnectedPoint) {
         self.connected_peers.insert(peer_id);
+        // TODO: Drop peers if over max_peer limit
 
         metrics::inc_counter(&metrics::PEER_CONNECT_EVENT_COUNT);
         metrics::set_gauge(&metrics::PEERS_CONNECTED, self.connected_peers() as i64);

beacon_node/eth2-libp2p/src/rpc/codec/base.rs

@@ -101,13 +101,15 @@ where
     type Error = <TCodec as Decoder>::Error;
 
     fn decode(&mut self, src: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error> {
+        // if we have only received the response code, wait for more bytes
+        if src.len() == 1 {
+            return Ok(None);
+        }
+        // using the response code determine which kind of payload needs to be decoded.
         let response_code = {
             if let Some(resp_code) = self.response_code {
                 resp_code
             } else {
-                // buffer should not be empty
-                debug_assert!(!src.is_empty());
-
                 let resp_byte = src.split_to(1);
                 let mut resp_code_byte = [0; 1];
                 resp_code_byte.copy_from_slice(&resp_byte);

beacon_node/eth2-libp2p/src/rpc/codec/ssz.rs

@@ -4,7 +4,7 @@ use crate::rpc::{
     protocol::{ProtocolId, RPCError},
 };
 use crate::rpc::{ErrorMessage, RPCErrorResponse, RPCRequest, RPCResponse};
-use bytes::{Bytes, BytesMut};
+use bytes::{BufMut, Bytes, BytesMut};
 use ssz::{Decode, Encode};
 use tokio::codec::{Decoder, Encoder};
 use unsigned_varint::codec::UviBytes;
@@ -56,6 +56,10 @@ impl Encoder for SSZInboundCodec {
                 .inner
                 .encode(Bytes::from(bytes), dst)
                 .map_err(RPCError::from);
+        } else {
+            // payload is empty, add a 0-byte length prefix
+            dst.reserve(1);
+            dst.put_u8(0);
         }
         Ok(())
     }
@@ -152,45 +156,49 @@ impl Decoder for SSZOutboundCodec {
     type Error = RPCError;
 
     fn decode(&mut self, src: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error> {
-        match self.inner.decode(src).map_err(RPCError::from) {
-            Ok(Some(packet)) => match self.protocol.message_name.as_str() {
+        if src.len() == 1 && src[0] == 0_u8 {
+            // the object is empty. We return the empty object if this is the case
+            match self.protocol.message_name.as_str() {
                 "hello" => match self.protocol.version.as_str() {
-                    "1" => Ok(Some(RPCResponse::Hello(HelloMessage::from_ssz_bytes(
-                        &packet,
-                    )?))),
+                    "1" => Err(RPCError::Custom(
+                        "Hello stream terminated unexpectedly".into(),
+                    )), // cannot have an empty HELLO message. The stream has terminated unexpectedly
                     _ => unreachable!("Cannot negotiate an unknown version"),
                 },
                 "goodbye" => Err(RPCError::InvalidProtocol("GOODBYE doesn't have a response")),
                 "beacon_blocks" => match self.protocol.version.as_str() {
-                    "1" => Ok(Some(RPCResponse::BeaconBlocks(packet.to_vec()))),
+                    "1" => Ok(Some(RPCResponse::BeaconBlocks(Vec::new()))),
                     _ => unreachable!("Cannot negotiate an unknown version"),
                 },
                 "recent_beacon_blocks" => match self.protocol.version.as_str() {
-                    "1" => Ok(Some(RPCResponse::RecentBeaconBlocks(packet.to_vec()))),
+                    "1" => Ok(Some(RPCResponse::RecentBeaconBlocks(Vec::new()))),
                     _ => unreachable!("Cannot negotiate an unknown version"),
                 },
                 _ => unreachable!("Cannot negotiate an unknown protocol"),
-            },
-            Ok(None) => {
-                // the object sent could be a empty. We return the empty object if this is the case
-                match self.protocol.message_name.as_str() {
+            }
+        } else {
+            match self.inner.decode(src).map_err(RPCError::from) {
+                Ok(Some(packet)) => match self.protocol.message_name.as_str() {
                     "hello" => match self.protocol.version.as_str() {
-                        "1" => Ok(None), // cannot have an empty HELLO message. The stream has terminated unexpectedly
+                        "1" => Ok(Some(RPCResponse::Hello(HelloMessage::from_ssz_bytes(
+                            &packet,
+                        )?))),
                         _ => unreachable!("Cannot negotiate an unknown version"),
                     },
                     "goodbye" => Err(RPCError::InvalidProtocol("GOODBYE doesn't have a response")),
                     "beacon_blocks" => match self.protocol.version.as_str() {
-                        "1" => Ok(Some(RPCResponse::BeaconBlocks(Vec::new()))),
+                        "1" => Ok(Some(RPCResponse::BeaconBlocks(packet.to_vec()))),
                         _ => unreachable!("Cannot negotiate an unknown version"),
                     },
                     "recent_beacon_blocks" => match self.protocol.version.as_str() {
-                        "1" => Ok(Some(RPCResponse::RecentBeaconBlocks(Vec::new()))),
+                        "1" => Ok(Some(RPCResponse::RecentBeaconBlocks(packet.to_vec()))),
                         _ => unreachable!("Cannot negotiate an unknown version"),
                     },
                     _ => unreachable!("Cannot negotiate an unknown protocol"),
-                }
+                },
+                Ok(None) => Ok(None), // waiting for more bytes
+                Err(e) => Err(e),
             }
-            Err(e) => Err(e),
         }
     }
 }

beacon_node/eth2-libp2p/src/rpc/methods.rs

@@ -1,6 +1,5 @@
 //!Available RPC methods types and ids.
 
-use ssz::{impl_decode_via_from, impl_encode_via_from};
 use ssz_derive::{Decode, Encode};
 use types::{Epoch, Hash256, Slot};
 
@@ -66,8 +65,38 @@ impl Into<u64> for GoodbyeReason {
     }
 }
 
-impl_encode_via_from!(GoodbyeReason, u64);
-impl_decode_via_from!(GoodbyeReason, u64);
+impl ssz::Encode for GoodbyeReason {
+    fn is_ssz_fixed_len() -> bool {
+        <u64 as ssz::Encode>::is_ssz_fixed_len()
+    }
+
+    fn ssz_fixed_len() -> usize {
+        <u64 as ssz::Encode>::ssz_fixed_len()
+    }
+
+    fn ssz_bytes_len(&self) -> usize {
+        0_u64.ssz_bytes_len()
+    }
+
+    fn ssz_append(&self, buf: &mut Vec<u8>) {
+        let conv: u64 = self.clone().into();
+        conv.ssz_append(buf)
+    }
+}
+
+impl ssz::Decode for GoodbyeReason {
+    fn is_ssz_fixed_len() -> bool {
+        <u64 as ssz::Decode>::is_ssz_fixed_len()
+    }
+
+    fn ssz_fixed_len() -> usize {
+        <u64 as ssz::Decode>::ssz_fixed_len()
+    }
+
+    fn from_ssz_bytes(bytes: &[u8]) -> Result<Self, ssz::DecodeError> {
+        u64::from_ssz_bytes(bytes).and_then(|n| Ok(n.into()))
+    }
+}
 
 /// Request a number of beacon block roots from a peer.
 #[derive(Encode, Decode, Clone, Debug, PartialEq)]
@@ -157,3 +186,53 @@ impl ErrorMessage {
         String::from_utf8(self.error_message.clone()).unwrap_or_else(|_| "".into())
     }
 }
+
+impl std::fmt::Display for HelloMessage {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "Hello Message: Fork Version: {:?}, Finalized Root: {}, Finalized Epoch: {}, Head Root: {}, Head Slot: {}", self.fork_version, self.finalized_root, self.finalized_epoch, self.head_root, self.head_slot)
+    }
+}
+
+impl std::fmt::Display for RPCResponse {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            RPCResponse::Hello(hello) => write!(f, "{}", hello),
+            RPCResponse::BeaconBlocks(data) => write!(f, "<BeaconBlocks>, len: {}", data.len()),
+            RPCResponse::RecentBeaconBlocks(data) => {
+                write!(f, "<RecentBeaconBlocks>, len: {}", data.len())
+            }
+        }
+    }
+}
+
+impl std::fmt::Display for RPCErrorResponse {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            RPCErrorResponse::Success(res) => write!(f, "{}", res),
+            RPCErrorResponse::InvalidRequest(err) => write!(f, "Invalid Request: {:?}", err),
+            RPCErrorResponse::ServerError(err) => write!(f, "Server Error: {:?}", err),
+            RPCErrorResponse::Unknown(err) => write!(f, "Unknown Error: {:?}", err),
+        }
+    }
+}
+
+impl std::fmt::Display for GoodbyeReason {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            GoodbyeReason::ClientShutdown => write!(f, "Client Shutdown"),
+            GoodbyeReason::IrrelevantNetwork => write!(f, "Irrelevant Network"),
+            GoodbyeReason::Fault => write!(f, "Fault"),
+            GoodbyeReason::Unknown => write!(f, "Unknown Reason"),
+        }
+    }
+}
+
+impl std::fmt::Display for BeaconBlocksRequest {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "Head Block Root: {},  Start Slot: {}, Count: {}, Step: {}",
+            self.head_block_root, self.start_slot, self.count, self.step
+        )
+    }
+}

beacon_node/eth2-libp2p/src/rpc/mod.rs

@@ -47,6 +47,16 @@ impl RPCEvent {
     }
 }
 
+impl std::fmt::Display for RPCEvent {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            RPCEvent::Request(id, req) => write!(f, "RPC Request(Id: {}, {})", id, req),
+            RPCEvent::Response(id, res) => write!(f, "RPC Response(Id: {}, {})", id, res),
+            RPCEvent::Error(id, err) => write!(f, "RPC Request(Id: {}, Error: {:?})", id, err),
+        }
+    }
+}
+
 /// Implements the libp2p `NetworkBehaviour` trait and therefore manages network-level
 /// logic.
 pub struct RPC<TSubstream> {

beacon_node/eth2-libp2p/src/rpc/protocol.rs

@@ -288,3 +288,14 @@ impl std::error::Error for RPCError {
         }
     }
 }
+
+impl std::fmt::Display for RPCRequest {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            RPCRequest::Hello(hello) => write!(f, "Hello Message: {}", hello),
+            RPCRequest::Goodbye(reason) => write!(f, "Goodbye: {}", reason),
+            RPCRequest::BeaconBlocks(req) => write!(f, "Beacon Blocks: {}", req),
+            RPCRequest::RecentBeaconBlocks(req) => write!(f, "Recent Beacon Blocks: {:?}", req),
+        }
+    }
+}

beacon_node/eth2-libp2p/src/service.rs

@@ -42,16 +42,21 @@ impl Service {
     pub fn new(config: NetworkConfig, log: slog::Logger) -> error::Result<Self> {
         trace!(log, "Libp2p Service starting");
 
+        let local_keypair = if let Some(hex_bytes) = &config.secret_key_hex {
+            keypair_from_hex(hex_bytes)?
+        } else {
+            load_private_key(&config, &log)
+        };
+
         // load the private key from CLI flag, disk or generate a new one
-        let local_private_key = load_private_key(&config, &log);
-        let local_peer_id = PeerId::from(local_private_key.public());
+        let local_peer_id = PeerId::from(local_keypair.public());
         info!(log, "Libp2p Service"; "peer_id" => format!("{:?}", local_peer_id));
 
         let mut swarm = {
             // Set up the transport - tcp/ws with secio and mplex/yamux
-            let transport = build_transport(local_private_key.clone());
+            let transport = build_transport(local_keypair.clone());
             // Lighthouse network behaviour
-            let behaviour = Behaviour::new(&local_private_key, &config, &log)?;
+            let behaviour = Behaviour::new(&local_keypair, &config, &log)?;
             Swarm::new(transport, behaviour, local_peer_id.clone())
         };
 
@@ -79,15 +84,32 @@ impl Service {
             }
         };
 
-        // attempt to connect to user-input libp2p nodes
-        for multiaddr in config.libp2p_nodes {
+        // helper closure for dialing peers
+        let mut dial_addr = |multiaddr: Multiaddr| {
             match Swarm::dial_addr(&mut swarm, multiaddr.clone()) {
                 Ok(()) => debug!(log, "Dialing libp2p peer"; "address" => format!("{}", multiaddr)),
                 Err(err) => debug!(
                     log,
-                    "Could not connect to peer"; "address" => format!("{}", multiaddr), "Error" => format!("{:?}", err)
+                    "Could not connect to peer"; "address" => format!("{}", multiaddr), "error" => format!("{:?}", err)
                 ),
             };
+        };
+
+        // attempt to connect to user-input libp2p nodes
+        for multiaddr in config.libp2p_nodes {
+            dial_addr(multiaddr);
+        }
+
+        // attempt to connect to any specified boot-nodes
+        for bootnode_enr in config.boot_nodes {
+            for multiaddr in bootnode_enr.multiaddr() {
+                // ignore udp multiaddr if it exists
+                let components = multiaddr.iter().collect::<Vec<_>>();
+                if let Protocol::Udp(_) = components[1] {
+                    continue;
+                }
+                dial_addr(multiaddr);
+            }
         }
 
         // subscribe to default gossipsub topics
@@ -145,16 +167,16 @@ impl Stream for Service {
     fn poll(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
         loop {
             match self.swarm.poll() {
-                //Behaviour events
                 Ok(Async::Ready(Some(event))) => match event {
-                    // TODO: Stub here for debugging
                     BehaviourEvent::GossipMessage {
+                        id,
                         source,
                         topics,
                         message,
                     } => {
                         trace!(self.log, "Gossipsub message received"; "service" => "Swarm");
                         return Ok(Async::Ready(Some(Libp2pEvent::PubsubMessage {
+                            id,
                             source,
                             topics,
                             message,
@@ -222,12 +244,34 @@ pub enum Libp2pEvent {
     PeerDisconnected(PeerId),
     /// Received pubsub message.
     PubsubMessage {
+        id: String,
         source: PeerId,
         topics: Vec<TopicHash>,
         message: PubsubMessage,
     },
 }
 
+fn keypair_from_hex(hex_bytes: &str) -> error::Result<Keypair> {
+    let hex_bytes = if hex_bytes.starts_with("0x") {
+        hex_bytes[2..].to_string()
+    } else {
+        hex_bytes.to_string()
+    };
+
+    hex::decode(&hex_bytes)
+        .map_err(|e| format!("Failed to parse p2p secret key bytes: {:?}", e).into())
+        .and_then(keypair_from_bytes)
+}
+
+fn keypair_from_bytes(mut bytes: Vec<u8>) -> error::Result<Keypair> {
+    libp2p::core::identity::secp256k1::SecretKey::from_bytes(&mut bytes)
+        .map(|secret| {
+            let keypair: libp2p::core::identity::secp256k1::Keypair = secret.into();
+            Keypair::Secp256k1(keypair)
+        })
+        .map_err(|e| format!("Unable to parse p2p secret key: {:?}", e).into())
+}
+
 /// Loads a private key from disk. If this fails, a new key is
 /// generated and is then saved to disk.
 ///

beacon_node/network/Cargo.toml

@@ -13,9 +13,11 @@ store =  { path = "../store" }
 eth2-libp2p =  { path = "../eth2-libp2p" }
 types = { path = "../../eth2/types" }
 slog = { version = "^2.2.3" , features = ["max_level_trace"] }
+hex = "0.3"
 eth2_ssz = "0.1"
 tree_hash = "0.1"
 futures = "0.1.25"
 error-chain = "0.12.0"
 tokio = "0.1.16"
 parking_lot = "0.9.0"
+smallvec = "0.6.10"

beacon_node/network/src/message_handler.rs

@@ -1,6 +1,6 @@
 use crate::error;
 use crate::service::NetworkMessage;
-use crate::sync::SimpleSync;
+use crate::sync::MessageProcessor;
 use beacon_chain::{BeaconChain, BeaconChainTypes};
 use eth2_libp2p::{
     behaviour::PubsubMessage,
@@ -9,18 +9,22 @@ use eth2_libp2p::{
 };
 use futures::future::Future;
 use futures::stream::Stream;
-use slog::{debug, trace, warn};
+use slog::{debug, o, trace, warn};
 use ssz::{Decode, DecodeError};
 use std::sync::Arc;
 use tokio::sync::mpsc;
 use types::{Attestation, AttesterSlashing, BeaconBlock, ProposerSlashing, VoluntaryExit};
 
-/// Handles messages received from the network and client and organises syncing.
+/// Handles messages received from the network and client and organises syncing. This
+/// functionality of this struct is to validate an decode messages from the network before
+/// passing them to the internal message processor. The message processor spawns a syncing thread
+/// which manages which blocks need to be requested and processed.
 pub struct MessageHandler<T: BeaconChainTypes> {
-    /// Currently loaded and initialised beacon chain.
-    _chain: Arc<BeaconChain<T>>,
-    /// The syncing framework.
-    sync: SimpleSync<T>,
+    /// A channel to the network service to allow for gossip propagation.
+    network_send: mpsc::UnboundedSender<NetworkMessage>,
+    /// Processes validated and decoded messages from the network. Has direct access to the
+    /// sync manager.
+    message_processor: MessageProcessor<T>,
     /// The `MessageHandler` logger.
     log: slog::Logger,
 }
@@ -34,8 +38,9 @@ pub enum HandlerMessage {
     PeerDisconnected(PeerId),
     /// An RPC response/request has been received.
     RPC(PeerId, RPCEvent),
-    /// A gossip message has been received.
-    PubsubMessage(PeerId, PubsubMessage),
+    /// A gossip message has been received. The fields are: message id, the peer that sent us this
+    /// message and the message itself.
+    PubsubMessage(String, PeerId, PubsubMessage),
 }
 
 impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
@@ -46,17 +51,20 @@ impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
         executor: &tokio::runtime::TaskExecutor,
         log: slog::Logger,
     ) -> error::Result<mpsc::UnboundedSender<HandlerMessage>> {
-        trace!(log, "Service starting");
+        let message_handler_log = log.new(o!("Service"=> "Message Handler"));
+        trace!(message_handler_log, "Service starting");
 
         let (handler_send, handler_recv) = mpsc::unbounded_channel();
-        // Initialise sync and begin processing in thread
-        let sync = SimpleSync::new(beacon_chain.clone(), network_send, &log);
+
+        // Initialise a message instance, which itself spawns the syncing thread.
+        let message_processor =
+            MessageProcessor::new(executor, beacon_chain, network_send.clone(), &log);
 
         // generate the Message handler
         let mut handler = MessageHandler {
-            _chain: beacon_chain.clone(),
-            sync,
-            log: log.clone(),
+            network_send,
+            message_processor,
+            log: message_handler_log,
         };
 
         // spawn handler task and move the message handler instance into the spawned thread
@@ -76,19 +84,19 @@ impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
         match message {
             // we have initiated a connection to a peer
             HandlerMessage::PeerDialed(peer_id) => {
-                self.sync.on_connect(peer_id);
+                self.message_processor.on_connect(peer_id);
             }
             // A peer has disconnected
             HandlerMessage::PeerDisconnected(peer_id) => {
-                self.sync.on_disconnect(peer_id);
+                self.message_processor.on_disconnect(peer_id);
             }
             // An RPC message request/response has been received
             HandlerMessage::RPC(peer_id, rpc_event) => {
                 self.handle_rpc_message(peer_id, rpc_event);
             }
             // An RPC message request/response has been received
-            HandlerMessage::PubsubMessage(peer_id, gossip) => {
-                self.handle_gossip(peer_id, gossip);
+            HandlerMessage::PubsubMessage(id, peer_id, gossip) => {
+                self.handle_gossip(id, peer_id, gossip);
             }
         }
     }
@@ -108,7 +116,7 @@ impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
     fn handle_rpc_request(&mut self, peer_id: PeerId, request_id: RequestId, request: RPCRequest) {
         match request {
             RPCRequest::Hello(hello_message) => {
-                self.sync
+                self.message_processor
                     .on_hello_request(peer_id, request_id, hello_message)
             }
             RPCRequest::Goodbye(goodbye_reason) => {
@@ -117,13 +125,13 @@ impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
                     "peer" => format!("{:?}", peer_id),
                     "reason" => format!("{:?}", goodbye_reason),
                 );
-                self.sync.on_disconnect(peer_id);
+                self.message_processor.on_disconnect(peer_id);
             }
             RPCRequest::BeaconBlocks(request) => self
-                .sync
+                .message_processor
                 .on_beacon_blocks_request(peer_id, request_id, request),
             RPCRequest::RecentBeaconBlocks(request) => self
-                .sync
+                .message_processor
                 .on_recent_beacon_blocks_request(peer_id, request_id, request),
         }
     }
@@ -150,12 +158,13 @@ impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
             RPCErrorResponse::Success(response) => {
                 match response {
                     RPCResponse::Hello(hello_message) => {
-                        self.sync.on_hello_response(peer_id, hello_message);
+                        self.message_processor
+                            .on_hello_response(peer_id, hello_message);
                     }
                     RPCResponse::BeaconBlocks(response) => {
                         match self.decode_beacon_blocks(&response) {
                             Ok(beacon_blocks) => {
-                                self.sync.on_beacon_blocks_response(
+                                self.message_processor.on_beacon_blocks_response(
                                     peer_id,
                                     request_id,
                                     beacon_blocks,
@@ -170,7 +179,7 @@ impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
                     RPCResponse::RecentBeaconBlocks(response) => {
                         match self.decode_beacon_blocks(&response) {
                             Ok(beacon_blocks) => {
-                                self.sync.on_recent_beacon_blocks_response(
+                                self.message_processor.on_recent_beacon_blocks_response(
                                     peer_id,
                                     request_id,
                                     beacon_blocks,
@@ -194,24 +203,37 @@ impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
     }
 
     /// Handle RPC messages
-    fn handle_gossip(&mut self, peer_id: PeerId, gossip_message: PubsubMessage) {
+    fn handle_gossip(&mut self, id: String, peer_id: PeerId, gossip_message: PubsubMessage) {
         match gossip_message {
             PubsubMessage::Block(message) => match self.decode_gossip_block(message) {
                 Ok(block) => {
-                    let _should_forward_on = self.sync.on_block_gossip(peer_id, block);
+                    let should_forward_on = self
+                        .message_processor
+                        .on_block_gossip(peer_id.clone(), block);
+                    // TODO: Apply more sophisticated validation and decoding logic
+                    if should_forward_on {
+                        self.propagate_message(id, peer_id.clone());
+                    }
                 }
                 Err(e) => {
                     debug!(self.log, "Invalid gossiped beacon block"; "peer_id" => format!("{}", peer_id), "Error" => format!("{:?}", e));
                 }
             },
             PubsubMessage::Attestation(message) => match self.decode_gossip_attestation(message) {
-                Ok(attestation) => self.sync.on_attestation_gossip(peer_id, attestation),
+                Ok(attestation) => {
+                    // TODO: Apply more sophisticated validation and decoding logic
+                    self.propagate_message(id, peer_id.clone());
+                    self.message_processor
+                        .on_attestation_gossip(peer_id, attestation);
+                }
                 Err(e) => {
                     debug!(self.log, "Invalid gossiped attestation"; "peer_id" => format!("{}", peer_id), "Error" => format!("{:?}", e));
                 }
             },
             PubsubMessage::VoluntaryExit(message) => match self.decode_gossip_exit(message) {
                 Ok(_exit) => {
+                    // TODO: Apply more sophisticated validation and decoding logic
+                    self.propagate_message(id, peer_id.clone());
                     // TODO: Handle exits
                     debug!(self.log, "Received a voluntary exit"; "peer_id" => format!("{}", peer_id) );
                 }
@@ -222,6 +244,8 @@ impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
             PubsubMessage::ProposerSlashing(message) => {
                 match self.decode_gossip_proposer_slashing(message) {
                     Ok(_slashing) => {
+                        // TODO: Apply more sophisticated validation and decoding logic
+                        self.propagate_message(id, peer_id.clone());
                         // TODO: Handle proposer slashings
                         debug!(self.log, "Received a proposer slashing"; "peer_id" => format!("{}", peer_id) );
                     }
@@ -233,6 +257,8 @@ impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
             PubsubMessage::AttesterSlashing(message) => {
                 match self.decode_gossip_attestation_slashing(message) {
                     Ok(_slashing) => {
+                        // TODO: Apply more sophisticated validation and decoding logic
+                        self.propagate_message(id, peer_id.clone());
                         // TODO: Handle attester slashings
                         debug!(self.log, "Received an attester slashing"; "peer_id" => format!("{}", peer_id) );
                     }
@@ -248,6 +274,21 @@ impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
         }
     }
 
+    /// Informs the network service that the message should be forwarded to other peers.
+    fn propagate_message(&mut self, message_id: String, propagation_source: PeerId) {
+        self.network_send
+            .try_send(NetworkMessage::Propagate {
+                propagation_source,
+                message_id,
+            })
+            .unwrap_or_else(|_| {
+                warn!(
+                    self.log,
+                    "Could not send propagation request to the network service"
+                )
+            });
+    }
+
     /* Decoding of gossipsub objects from the network.
      *
      * The decoding is done in the message handler as it has access to to a `BeaconChain` and can

beacon_node/network/src/service.rs

@@ -34,13 +34,8 @@ impl<T: BeaconChainTypes + 'static> Service<T> {
         // build the network channel
         let (network_send, network_recv) = mpsc::unbounded_channel::<NetworkMessage>();
         // launch message handler thread
-        let message_handler_log = log.new(o!("Service" => "MessageHandler"));
-        let message_handler_send = MessageHandler::spawn(
-            beacon_chain,
-            network_send.clone(),
-            executor,
-            message_handler_log,
-        )?;
+        let message_handler_send =
+            MessageHandler::spawn(beacon_chain, network_send.clone(), executor, log.clone())?;
 
         let network_log = log.new(o!("Service" => "Network"));
         // launch libp2p service
@@ -159,12 +154,23 @@ fn network_service(
             // poll the network channel
             match network_recv.poll() {
                 Ok(Async::Ready(Some(message))) => match message {
-                    NetworkMessage::Send(peer_id, outgoing_message) => match outgoing_message {
-                        OutgoingMessage::RPC(rpc_event) => {
-                            trace!(log, "Sending RPC Event: {:?}", rpc_event);
-                            libp2p_service.lock().swarm.send_rpc(peer_id, rpc_event);
-                        }
-                    },
+                    NetworkMessage::RPC(peer_id, rpc_event) => {
+                        trace!(log, "{}", rpc_event);
+                        libp2p_service.lock().swarm.send_rpc(peer_id, rpc_event);
+                    }
+                    NetworkMessage::Propagate {
+                        propagation_source,
+                        message_id,
+                    } => {
+                        trace!(log, "Propagating gossipsub message";
+                        "propagation_peer" => format!("{:?}", propagation_source),
+                        "message_id" => format!("{}", message_id),
+                        );
+                        libp2p_service
+                            .lock()
+                            .swarm
+                            .propagate_message(&propagation_source, message_id);
+                    }
                     NetworkMessage::Publish { topics, message } => {
                         debug!(log, "Sending pubsub message"; "topics" => format!("{:?}",topics));
                         libp2p_service.lock().swarm.publish(&topics, message);
@@ -185,7 +191,7 @@ fn network_service(
             match libp2p_service.lock().poll() {
                 Ok(Async::Ready(Some(event))) => match event {
                     Libp2pEvent::RPC(peer_id, rpc_event) => {
-                        trace!(log, "RPC Event: RPC message received: {:?}", rpc_event);
+                        trace!(log, "{}", rpc_event);
                         message_handler_send
                             .try_send(HandlerMessage::RPC(peer_id, rpc_event))
                             .map_err(|_| "Failed to send RPC to handler")?;
@@ -203,13 +209,14 @@ fn network_service(
                             .map_err(|_| "Failed to send PeerDisconnected to handler")?;
                     }
                     Libp2pEvent::PubsubMessage {
-                        source, message, ..
+                        id,
+                        source,
+                        message,
+                        ..
                     } => {
-                        //TODO: Decide if we need to propagate the topic upwards. (Potentially for
-                        //attestations)
                         message_handler_send
-                            .try_send(HandlerMessage::PubsubMessage(source, message))
-                            .map_err(|_| " failed to send pubsub message to handler")?;
+                            .try_send(HandlerMessage::PubsubMessage(id, source, message))
+                            .map_err(|_| "Failed to send pubsub message to handler")?;
                     }
                 },
                 Ok(Async::Ready(None)) => unreachable!("Stream never ends"),
@@ -225,19 +232,16 @@ fn network_service(
 /// Types of messages that the network service can receive.
 #[derive(Debug)]
 pub enum NetworkMessage {
-    /// Send a message to libp2p service.
-    //TODO: Define typing for messages across the wire
-    Send(PeerId, OutgoingMessage),
-    /// Publish a message to pubsub mechanism.
+    /// Send an RPC message to the libp2p service.
+    RPC(PeerId, RPCEvent),
+    /// Publish a message to gossipsub.
     Publish {
         topics: Vec<Topic>,
         message: PubsubMessage,
     },
-}
-
-/// Type of outgoing messages that can be sent through the network service.
-#[derive(Debug)]
-pub enum OutgoingMessage {
-    /// Send an RPC request/response.
-    RPC(RPCEvent),
+    /// Propagate a received gossipsub message
+    Propagate {
+        propagation_source: PeerId,
+        message_id: String,
+    },
 }

beacon_node/network/src/sync/mod.rs

@@ -4,7 +4,7 @@ mod manager;
 /// Stores the various syncing methods for the beacon chain.
 mod simple_sync;
 
-pub use simple_sync::SimpleSync;
+pub use simple_sync::MessageProcessor;
 
 /// Currently implemented sync methods.
 pub enum SyncMethod {

beacon_node/network/src/sync/simple_sync.rs

@@ -1,23 +1,26 @@
-use super::manager::{ImportManager, ImportManagerOutcome};
-use crate::service::{NetworkMessage, OutgoingMessage};
-use beacon_chain::{BeaconChain, BeaconChainTypes, BlockProcessingOutcome};
+use super::manager::SyncMessage;
+use crate::service::NetworkMessage;
+use beacon_chain::{
+    AttestationProcessingOutcome, BeaconChain, BeaconChainTypes, BlockProcessingOutcome,
+};
 use eth2_libp2p::rpc::methods::*;
 use eth2_libp2p::rpc::{RPCEvent, RPCRequest, RPCResponse, RequestId};
 use eth2_libp2p::PeerId;
-use slog::{debug, info, o, trace, warn};
+use slog::{debug, error, info, o, trace, warn};
 use ssz::Encode;
-use std::ops::Sub;
 use std::sync::Arc;
 use store::Store;
-use tokio::sync::mpsc;
+use tokio::sync::{mpsc, oneshot};
+use tree_hash::SignedRoot;
 use types::{Attestation, BeaconBlock, Epoch, EthSpec, Hash256, Slot};
 
+//TODO: Put a maximum limit on the number of block that can be requested.
+//TODO: Rate limit requests
+
 /// If a block is more than `FUTURE_SLOT_TOLERANCE` slots ahead of our slot clock, we drop it.
 /// Otherwise we queue it.
 pub(crate) const FUTURE_SLOT_TOLERANCE: u64 = 1;
 
-/// The number of slots behind our head that we still treat a peer as a fully synced peer.
-const FULL_PEER_TOLERANCE: u64 = 10;
 const SHOULD_FORWARD_GOSSIP_BLOCK: bool = true;
 const SHOULD_NOT_FORWARD_GOSSIP_BLOCK: bool = false;
 
@@ -49,45 +52,63 @@ impl<T: BeaconChainTypes> From<&Arc<BeaconChain<T>>> for PeerSyncInfo {
     }
 }
 
-/// The current syncing state.
-#[derive(PartialEq)]
-pub enum SyncState {
-    _Idle,
-    _Downloading,
-    _Stopped,
-}
-
-/// Simple Syncing protocol.
-pub struct SimpleSync<T: BeaconChainTypes> {
+/// Processes validated messages from the network. It relays necessary data to the syncing thread
+/// and processes blocks from the pubsub network.
+pub struct MessageProcessor<T: BeaconChainTypes> {
     /// A reference to the underlying beacon chain.
     chain: Arc<BeaconChain<T>>,
-    manager: ImportManager<T>,
+    /// A channel to the syncing thread.
+    sync_send: mpsc::UnboundedSender<SyncMessage<T::EthSpec>>,
+    /// A oneshot channel for destroying the sync thread.
+    _sync_exit: oneshot::Sender<()>,
+    /// A nextwork context to return and handle RPC requests.
     network: NetworkContext,
+    /// The `RPCHandler` logger.
     log: slog::Logger,
 }
 
-impl<T: BeaconChainTypes> SimpleSync<T> {
-    /// Instantiate a `SimpleSync` instance, with no peers and an empty queue.
+impl<T: BeaconChainTypes> MessageProcessor<T> {
+    /// Instantiate a `MessageProcessor` instance
     pub fn new(
+        executor: &tokio::runtime::TaskExecutor,
         beacon_chain: Arc<BeaconChain<T>>,
         network_send: mpsc::UnboundedSender<NetworkMessage>,
         log: &slog::Logger,
     ) -> Self {
         let sync_logger = log.new(o!("Service"=> "Sync"));
+        let sync_network_context = NetworkContext::new(network_send.clone(), sync_logger.clone());
 
-        SimpleSync {
-            chain: beacon_chain.clone(),
-            manager: ImportManager::new(beacon_chain, log),
+        // spawn the sync thread
+        let (sync_send, _sync_exit) = super::manager::spawn(
+            executor,
+            Arc::downgrade(&beacon_chain),
+            sync_network_context,
+            sync_logger,
+        );
+
+        MessageProcessor {
+            chain: beacon_chain,
+            sync_send,
+            _sync_exit,
             network: NetworkContext::new(network_send, log.clone()),
-            log: sync_logger,
+            log: log.clone(),
         }
     }
 
+    fn send_to_sync(&mut self, message: SyncMessage<T::EthSpec>) {
+        self.sync_send.try_send(message).unwrap_or_else(|_| {
+            warn!(
+                self.log,
+                "Could not send message to the sync service";
+            )
+        });
+    }
+
     /// Handle a peer disconnect.
     ///
     /// Removes the peer from the manager.
     pub fn on_disconnect(&mut self, peer_id: PeerId) {
-        self.manager.peer_disconnect(&peer_id);
+        self.send_to_sync(SyncMessage::Disconnect(peer_id));
     }
 
     /// Handle the connection of a new peer.
@@ -107,6 +128,7 @@ impl<T: BeaconChainTypes> SimpleSync<T> {
         request_id: RequestId,
         hello: HelloMessage,
     ) {
+        // ignore hello responses if we are shutting down
         trace!(self.log, "HelloRequest"; "peer" => format!("{:?}", peer_id));
 
         // Say hello back.
@@ -149,7 +171,7 @@ impl<T: BeaconChainTypes> SimpleSync<T> {
         } else if remote.finalized_epoch <= local.finalized_epoch
             && remote.finalized_root != Hash256::zero()
             && local.finalized_root != Hash256::zero()
-            && (self.root_at_slot(start_slot(remote.finalized_epoch))
+            && (self.chain.root_at_slot(start_slot(remote.finalized_epoch))
                 != Some(remote.finalized_root))
         {
             // The remotes finalized epoch is less than or greater than ours, but the block root is
@@ -189,18 +211,16 @@ impl<T: BeaconChainTypes> SimpleSync<T> {
             .exists::<BeaconBlock<T::EthSpec>>(&remote.head_root)
             .unwrap_or_else(|_| false)
         {
+            trace!(
+                self.log, "Peer with known chain found";
+                "peer" => format!("{:?}", peer_id),
+                "remote_head_slot" => remote.head_slot,
+                "remote_latest_finalized_epoch" => remote.finalized_epoch,
+            );
+
             // If the node's best-block is already known to us and they are close to our current
             // head, treat them as a fully sync'd peer.
-            if self.chain.best_slot().sub(remote.head_slot).as_u64() < FULL_PEER_TOLERANCE {
-                self.manager.add_full_peer(peer_id);
-                self.process_sync();
-            } else {
-                debug!(
-                    self.log,
-                    "Out of sync peer connected";
-                    "peer" => format!("{:?}", peer_id),
-                );
-            }
+            self.send_to_sync(SyncMessage::AddPeer(peer_id, remote));
         } else {
             // The remote node has an equal or great finalized epoch and we don't know it's head.
             //
@@ -212,87 +232,10 @@ impl<T: BeaconChainTypes> SimpleSync<T> {
                 "local_finalized_epoch" => local.finalized_epoch,
                 "remote_latest_finalized_epoch" => remote.finalized_epoch,
             );
-
-            self.manager.add_peer(peer_id, remote);
-            self.process_sync();
+            self.send_to_sync(SyncMessage::AddPeer(peer_id, remote));
         }
     }
 
-    fn process_sync(&mut self) {
-        loop {
-            match self.manager.poll() {
-                ImportManagerOutcome::Hello(peer_id) => {
-                    trace!(
-                        self.log,
-                        "RPC Request";
-                        "method" => "HELLO",
-                        "peer" => format!("{:?}", peer_id)
-                    );
-                    self.network.send_rpc_request(
-                        None,
-                        peer_id,
-                        RPCRequest::Hello(hello_message(&self.chain)),
-                    );
-                }
-                ImportManagerOutcome::RequestBlocks {
-                    peer_id,
-                    request_id,
-                    request,
-                } => {
-                    trace!(
-                        self.log,
-                        "RPC Request";
-                        "method" => "BeaconBlocks",
-                        "id" => request_id,
-                        "count" => request.count,
-                        "peer" => format!("{:?}", peer_id)
-                    );
-                    self.network.send_rpc_request(
-                        Some(request_id),
-                        peer_id.clone(),
-                        RPCRequest::BeaconBlocks(request),
-                    );
-                }
-                ImportManagerOutcome::RecentRequest(peer_id, req) => {
-                    trace!(
-                        self.log,
-                        "RPC Request";
-                        "method" => "RecentBeaconBlocks",
-                        "count" => req.block_roots.len(),
-                        "peer" => format!("{:?}", peer_id)
-                    );
-                    self.network.send_rpc_request(
-                        None,
-                        peer_id.clone(),
-                        RPCRequest::RecentBeaconBlocks(req),
-                    );
-                }
-                ImportManagerOutcome::DownvotePeer(peer_id) => {
-                    trace!(
-                        self.log,
-                        "Peer downvoted";
-                        "peer" => format!("{:?}", peer_id)
-                    );
-                    // TODO: Implement reputation
-                    self.network
-                        .disconnect(peer_id.clone(), GoodbyeReason::Fault);
-                }
-                ImportManagerOutcome::Idle => {
-                    // nothing to do
-                    return;
-                }
-            }
-        }
-    }
-
-    //TODO: Move to beacon chain
-    fn root_at_slot(&self, target_slot: Slot) -> Option<Hash256> {
-        self.chain
-            .rev_iter_block_roots()
-            .find(|(_root, slot)| *slot == target_slot)
-            .map(|(root, _slot)| root)
-    }
-
     /// Handle a `RecentBeaconBlocks` request from the peer.
     pub fn on_recent_beacon_blocks_request(
         &mut self,
@@ -321,7 +264,7 @@ impl<T: BeaconChainTypes> SimpleSync<T> {
 
         debug!(
             self.log,
-            "BlockBodiesRequest";
+            "RecentBeaconBlocksRequest";
             "peer" => format!("{:?}", peer_id),
             "requested" => request.block_roots.len(),
             "returned" => blocks.len(),
@@ -380,18 +323,16 @@ impl<T: BeaconChainTypes> SimpleSync<T> {
         blocks.reverse();
         blocks.dedup_by_key(|brs| brs.slot);
 
-        if blocks.len() as u64 != req.count {
-            debug!(
-                self.log,
-                "BeaconBlocksRequest response";
-                "peer" => format!("{:?}", peer_id),
-                "msg" => "Failed to return all requested hashes",
-                "start_slot" => req.start_slot,
-                "current_slot" => self.chain.present_slot(),
-                "requested" => req.count,
-                "returned" => blocks.len(),
-            );
-        }
+        debug!(
+            self.log,
+            "BeaconBlocksRequest response";
+            "peer" => format!("{:?}", peer_id),
+            "msg" => "Failed to return all requested hashes",
+            "start_slot" => req.start_slot,
+            "current_slot" => self.chain.slot().unwrap_or_else(|_| Slot::from(0_u64)).as_u64(),
+            "requested" => req.count,
+            "returned" => blocks.len(),
+        );
 
         self.network.send_rpc_response(
             peer_id,
@@ -414,10 +355,11 @@ impl<T: BeaconChainTypes> SimpleSync<T> {
             "count" => beacon_blocks.len(),
         );
 
-        self.manager
-            .beacon_blocks_response(peer_id, request_id, beacon_blocks);
-
-        self.process_sync();
+        self.send_to_sync(SyncMessage::BeaconBlocksResponse {
+            peer_id,
+            request_id,
+            beacon_blocks,
+        });
     }
 
     /// Handle a `RecentBeaconBlocks` response from the peer.
@@ -429,15 +371,16 @@ impl<T: BeaconChainTypes> SimpleSync<T> {
     ) {
         debug!(
             self.log,
-            "BeaconBlocksResponse";
+            "RecentBeaconBlocksResponse";
             "peer" => format!("{:?}", peer_id),
             "count" => beacon_blocks.len(),
         );
 
-        self.manager
-            .recent_blocks_response(peer_id, request_id, beacon_blocks);
-
-        self.process_sync();
+        self.send_to_sync(SyncMessage::RecentBeaconBlocksResponse {
+            peer_id,
+            request_id,
+            beacon_blocks,
+        });
     }
 
     /// Process a gossip message declaring a new block.
@@ -446,8 +389,8 @@ impl<T: BeaconChainTypes> SimpleSync<T> {
     ///
     /// Returns a `bool` which, if `true`, indicates we should forward the block to our peers.
     pub fn on_block_gossip(&mut self, peer_id: PeerId, block: BeaconBlock<T::EthSpec>) -> bool {
-        if let Ok(outcome) = self.chain.process_block(block.clone()) {
-            match outcome {
+        match self.chain.process_block(block.clone()) {
+            Ok(outcome) => match outcome {
                 BlockProcessingOutcome::Processed { .. } => {
                     trace!(self.log, "Gossipsub block processed";
                             "peer_id" => format!("{:?}",peer_id));
@@ -455,9 +398,9 @@ impl<T: BeaconChainTypes> SimpleSync<T> {
                 }
                 BlockProcessingOutcome::ParentUnknown { parent: _ } => {
                     // Inform the sync manager to find parents for this block
-                    trace!(self.log, "Unknown parent gossip";
+                    trace!(self.log, "Block with unknown parent received";
                             "peer_id" => format!("{:?}",peer_id));
-                    self.manager.add_unknown_block(block.clone(), peer_id);
+                    self.send_to_sync(SyncMessage::UnknownBlock(peer_id, block.clone()));
                     SHOULD_FORWARD_GOSSIP_BLOCK
                 }
                 BlockProcessingOutcome::FutureSlot {
@@ -468,10 +411,36 @@ impl<T: BeaconChainTypes> SimpleSync<T> {
                     SHOULD_FORWARD_GOSSIP_BLOCK
                 }
                 BlockProcessingOutcome::BlockIsAlreadyKnown => SHOULD_FORWARD_GOSSIP_BLOCK,
-                _ => SHOULD_NOT_FORWARD_GOSSIP_BLOCK,
+                other => {
+                    warn!(
+                        self.log,
+                        "Invalid gossip beacon block";
+                        "outcome" => format!("{:?}", other),
+                        "block root" => format!("{}", Hash256::from_slice(&block.signed_root()[..])),
+                        "block slot" => block.slot
+                    );
+                    trace!(
+                        self.log,
+                        "Invalid gossip beacon block ssz";
+                        "ssz" => format!("0x{}", hex::encode(block.as_ssz_bytes())),
+                    );
+                    SHOULD_NOT_FORWARD_GOSSIP_BLOCK //TODO: Decide if we want to forward these
+                }
+            },
+            Err(e) => {
+                error!(
+                    self.log,
+                    "Error processing gossip beacon block";
+                    "error" => format!("{:?}", e),
+                    "block slot" => block.slot
+                );
+                trace!(
+                    self.log,
+                    "Erroneous gossip beacon block ssz";
+                    "ssz" => format!("0x{}", hex::encode(block.as_ssz_bytes())),
+                );
+                SHOULD_NOT_FORWARD_GOSSIP_BLOCK
             }
-        } else {
-            SHOULD_NOT_FORWARD_GOSSIP_BLOCK
         }
     }
 
@@ -479,27 +448,37 @@ impl<T: BeaconChainTypes> SimpleSync<T> {
     ///
     /// Not currently implemented.
     pub fn on_attestation_gossip(&mut self, _peer_id: PeerId, msg: Attestation<T::EthSpec>) {
-        match self.chain.process_attestation(msg) {
-            Ok(outcome) => info!(
-                self.log,
-                "Processed attestation";
-                "source" => "gossip",
-                "outcome" => format!("{:?}", outcome)
-            ),
+        match self.chain.process_attestation(msg.clone()) {
+            Ok(outcome) => {
+                info!(
+                    self.log,
+                    "Processed attestation";
+                    "source" => "gossip",
+                    "outcome" => format!("{:?}", outcome)
+                );
+
+                if outcome != AttestationProcessingOutcome::Processed {
+                    trace!(
+                        self.log,
+                        "Invalid gossip attestation ssz";
+                        "ssz" => format!("0x{}", hex::encode(msg.as_ssz_bytes())),
+                    );
+                }
+            }
             Err(e) => {
-                warn!(self.log, "InvalidAttestation"; "source" => "gossip", "error" => format!("{:?}", e))
+                trace!(
+                    self.log,
+                    "Erroneous gossip attestation ssz";
+                    "ssz" => format!("0x{}", hex::encode(msg.as_ssz_bytes())),
+                );
+                error!(self.log, "Invalid gossip attestation"; "error" => format!("{:?}", e));
             }
         }
     }
-
-    /// Generates our current state in the form of a HELLO RPC message.
-    pub fn generate_hello(&self) -> HelloMessage {
-        hello_message(&self.chain)
-    }
 }
 
 /// Build a `HelloMessage` representing the state of the given `beacon_chain`.
-fn hello_message<T: BeaconChainTypes>(beacon_chain: &BeaconChain<T>) -> HelloMessage {
+pub(crate) fn hello_message<T: BeaconChainTypes>(beacon_chain: &BeaconChain<T>) -> HelloMessage {
     let state = &beacon_chain.head().beacon_state;
 
     HelloMessage {
@@ -525,6 +504,12 @@ impl NetworkContext {
     }
 
     pub fn disconnect(&mut self, peer_id: PeerId, reason: GoodbyeReason) {
+        warn!(
+            &self.log,
+            "Disconnecting peer (RPC)";
+            "reason" => format!("{:?}", reason),
+            "peer_id" => format!("{:?}", peer_id),
+        );
         self.send_rpc_request(None, peer_id, RPCRequest::Goodbye(reason))
         // TODO: disconnect peers.
     }
@@ -554,12 +539,8 @@ impl NetworkContext {
     }
 
     fn send_rpc_event(&mut self, peer_id: PeerId, rpc_event: RPCEvent) {
-        self.send(peer_id, OutgoingMessage::RPC(rpc_event))
-    }
-
-    fn send(&mut self, peer_id: PeerId, outgoing_message: OutgoingMessage) {
         self.network_send
-            .try_send(NetworkMessage::Send(peer_id, outgoing_message))
+            .try_send(NetworkMessage::RPC(peer_id, rpc_event))
             .unwrap_or_else(|_| {
                 warn!(
                     self.log,

beacon_node/rest_api/Cargo.toml

@@ -14,20 +14,26 @@ store = { path = "../store" }
 version = { path = "../version" }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "^1.0"
+serde_yaml = "0.8"
 slog = "^2.2.3"
 slog-term = "^2.4.0"
 slog-async = "^2.3.0"
+eth2_ssz = { path = "../../eth2/utils/ssz" }
+eth2_ssz_derive = { path = "../../eth2/utils/ssz_derive" }
 state_processing = { path = "../../eth2/state_processing" }
 types = { path = "../../eth2/types" }
 clap = "2.32.0"
 http = "^0.1.17"
 prometheus = { version = "^0.6", features = ["process"] }
-hyper = "0.12.32"
-futures = "0.1"
+hyper = "0.12.34"
 exit-future = "0.1.3"
 tokio = "0.1.17"
 url = "2.0"
 lazy_static = "1.3.0"
+eth2_config = { path = "../../eth2/utils/eth2_config" }
 lighthouse_metrics = { path = "../../eth2/utils/lighthouse_metrics" }
 slot_clock = { path = "../../eth2/utils/slot_clock" }
 hex = "0.3.2"
+parking_lot = "0.9"
+futures = "0.1.25"
+

beacon_node/rest_api/src/beacon.rs

@@ -1,17 +1,25 @@
-use super::{success_response, ApiResult};
-use crate::{helpers::*, ApiError, UrlQuery};
+use crate::helpers::*;
+use crate::response_builder::ResponseBuilder;
+use crate::{ApiError, ApiResult, UrlQuery};
 use beacon_chain::{BeaconChain, BeaconChainTypes};
 use hyper::{Body, Request};
 use serde::Serialize;
+use ssz_derive::Encode;
 use std::sync::Arc;
 use store::Store;
-use types::{BeaconBlock, BeaconState, EthSpec, Hash256, Slot};
+use types::{BeaconBlock, BeaconState, Epoch, EthSpec, Hash256, Slot, Validator};
 
-#[derive(Serialize)]
+#[derive(Serialize, Encode)]
 pub struct HeadResponse {
     pub slot: Slot,
     pub block_root: Hash256,
     pub state_root: Hash256,
+    pub finalized_slot: Slot,
+    pub finalized_block_root: Hash256,
+    pub justified_slot: Slot,
+    pub justified_block_root: Hash256,
+    pub previous_justified_slot: Slot,
+    pub previous_justified_block_root: Hash256,
 }
 
 /// HTTP handler to return a `BeaconBlock` at a given `root` or `slot`.
@@ -21,19 +29,36 @@ pub fn get_head<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult
         .get::<Arc<BeaconChain<T>>>()
         .ok_or_else(|| ApiError::ServerError("Beacon chain extension missing".to_string()))?;
 
+    let chain_head = beacon_chain.head();
+
     let head = HeadResponse {
-        slot: beacon_chain.head().beacon_state.slot,
-        block_root: beacon_chain.head().beacon_block_root,
-        state_root: beacon_chain.head().beacon_state_root,
+        slot: chain_head.beacon_state.slot,
+        block_root: chain_head.beacon_block_root,
+        state_root: chain_head.beacon_state_root,
+        finalized_slot: chain_head
+            .beacon_state
+            .finalized_checkpoint
+            .epoch
+            .start_slot(T::EthSpec::slots_per_epoch()),
+        finalized_block_root: chain_head.beacon_state.finalized_checkpoint.root,
+        justified_slot: chain_head
+            .beacon_state
+            .current_justified_checkpoint
+            .epoch
+            .start_slot(T::EthSpec::slots_per_epoch()),
+        justified_block_root: chain_head.beacon_state.current_justified_checkpoint.root,
+        previous_justified_slot: chain_head
+            .beacon_state
+            .previous_justified_checkpoint
+            .epoch
+            .start_slot(T::EthSpec::slots_per_epoch()),
+        previous_justified_block_root: chain_head.beacon_state.previous_justified_checkpoint.root,
     };
 
-    let json: String = serde_json::to_string(&head)
-        .map_err(|e| ApiError::ServerError(format!("Unable to serialize HeadResponse: {:?}", e)))?;
-
-    Ok(success_response(Body::from(json)))
+    ResponseBuilder::new(&req)?.body(&head)
 }
 
-#[derive(Serialize)]
+#[derive(Serialize, Encode)]
 #[serde(bound = "T: EthSpec")]
 pub struct BlockResponse<T: EthSpec> {
     pub root: Hash256,
@@ -55,7 +80,7 @@ pub fn get_block<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult
             let target = parse_slot(&value)?;
 
             block_root_at_slot(&beacon_chain, target).ok_or_else(|| {
-                ApiError::NotFound(format!("Unable to find BeaconBlock for slot {}", target))
+                ApiError::NotFound(format!("Unable to find BeaconBlock for slot {:?}", target))
             })?
         }
         ("root", value) => parse_root(&value)?,
@@ -67,7 +92,7 @@ pub fn get_block<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult
         .get::<BeaconBlock<T::EthSpec>>(&block_root)?
         .ok_or_else(|| {
             ApiError::NotFound(format!(
-                "Unable to find BeaconBlock for root {}",
+                "Unable to find BeaconBlock for root {:?}",
                 block_root
             ))
         })?;
@@ -77,34 +102,62 @@ pub fn get_block<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult
         beacon_block: block,
     };
 
-    let json: String = serde_json::to_string(&response).map_err(|e| {
-        ApiError::ServerError(format!("Unable to serialize BlockResponse: {:?}", e))
-    })?;
-
-    Ok(success_response(Body::from(json)))
+    ResponseBuilder::new(&req)?.body(&response)
 }
 
 /// HTTP handler to return a `BeaconBlock` root at a given `slot`.
 pub fn get_block_root<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
-    let beacon_chain = req
-        .extensions()
-        .get::<Arc<BeaconChain<T>>>()
-        .ok_or_else(|| ApiError::ServerError("Beacon chain extension missing".to_string()))?;
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
 
     let slot_string = UrlQuery::from_request(&req)?.only_one("slot")?;
     let target = parse_slot(&slot_string)?;
 
     let root = block_root_at_slot(&beacon_chain, target).ok_or_else(|| {
-        ApiError::NotFound(format!("Unable to find BeaconBlock for slot {}", target))
+        ApiError::NotFound(format!("Unable to find BeaconBlock for slot {:?}", target))
     })?;
 
-    let json: String = serde_json::to_string(&root)
-        .map_err(|e| ApiError::ServerError(format!("Unable to serialize root: {:?}", e)))?;
-
-    Ok(success_response(Body::from(json)))
+    ResponseBuilder::new(&req)?.body(&root)
 }
 
-#[derive(Serialize)]
+/// HTTP handler to return the `Fork` of the current head.
+pub fn get_fork<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
+    ResponseBuilder::new(&req)?.body(&beacon_chain.head().beacon_state.fork)
+}
+
+/// HTTP handler to return the set of validators for an `Epoch`
+///
+/// The `Epoch` parameter can be any epoch number. If it is not specified,
+/// the current epoch is assumed.
+pub fn get_validators<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
+
+    let epoch = match UrlQuery::from_request(&req) {
+        // We have some parameters, so make sure it's the epoch one and parse it
+        Ok(query) => query
+            .only_one("epoch")?
+            .parse::<u64>()
+            .map(Epoch::from)
+            .map_err(|e| {
+                ApiError::BadRequest(format!("Invalid epoch parameter, must be a u64. {:?}", e))
+            })?,
+        // In this case, our url query did not contain any parameters, so we take the default
+        Err(_) => beacon_chain.epoch().map_err(|e| {
+            ApiError::ServerError(format!("Unable to determine current epoch: {:?}", e))
+        })?,
+    };
+
+    let all_validators = &beacon_chain.head().beacon_state.validators;
+    let active_vals: Vec<Validator> = all_validators
+        .iter()
+        .filter(|v| v.is_active_at(epoch))
+        .cloned()
+        .collect();
+
+    ResponseBuilder::new(&req)?.body(&active_vals)
+}
+
+#[derive(Serialize, Encode)]
 #[serde(bound = "T: EthSpec")]
 pub struct StateResponse<T: EthSpec> {
     pub root: Hash256,
@@ -116,13 +169,23 @@ pub struct StateResponse<T: EthSpec> {
 /// Will not return a state if the request slot is in the future. Will return states higher than
 /// the current head by skipping slots.
 pub fn get_state<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
-    let beacon_chain = req
-        .extensions()
-        .get::<Arc<BeaconChain<T>>>()
-        .ok_or_else(|| ApiError::ServerError("Beacon chain extension missing".to_string()))?;
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
+    let head_state = beacon_chain.head().beacon_state;
 
-    let query_params = ["root", "slot"];
-    let (key, value) = UrlQuery::from_request(&req)?.first_of(&query_params)?;
+    let (key, value) = match UrlQuery::from_request(&req) {
+        Ok(query) => {
+            // We have *some* parameters, just check them.
+            let query_params = ["root", "slot"];
+            query.first_of(&query_params)?
+        }
+        Err(ApiError::BadRequest(_)) => {
+            // No parameters provided at all, use current slot.
+            (String::from("slot"), head_state.slot.to_string())
+        }
+        Err(e) => {
+            return Err(e);
+        }
+    };
 
     let (root, state): (Hash256, BeaconState<T::EthSpec>) = match (key.as_ref(), value) {
         ("slot", value) => state_at_slot(&beacon_chain, parse_slot(&value)?)?,
@@ -132,7 +195,7 @@ pub fn get_state<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult
             let state = beacon_chain
                 .store
                 .get(root)?
-                .ok_or_else(|| ApiError::NotFound(format!("No state for root: {}", root)))?;
+                .ok_or_else(|| ApiError::NotFound(format!("No state for root: {:?}", root)))?;
 
             (*root, state)
         }
@@ -144,11 +207,7 @@ pub fn get_state<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult
         beacon_state: state,
     };
 
-    let json: String = serde_json::to_string(&response).map_err(|e| {
-        ApiError::ServerError(format!("Unable to serialize StateResponse: {:?}", e))
-    })?;
-
-    Ok(success_response(Body::from(json)))
+    ResponseBuilder::new(&req)?.body(&response)
 }
 
 /// HTTP handler to return a `BeaconState` root at a given `slot`.
@@ -156,39 +215,33 @@ pub fn get_state<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult
 /// Will not return a state if the request slot is in the future. Will return states higher than
 /// the current head by skipping slots.
 pub fn get_state_root<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
-    let beacon_chain = req
-        .extensions()
-        .get::<Arc<BeaconChain<T>>>()
-        .ok_or_else(|| ApiError::ServerError("Beacon chain extension missing".to_string()))?;
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
 
     let slot_string = UrlQuery::from_request(&req)?.only_one("slot")?;
     let slot = parse_slot(&slot_string)?;
 
     let root = state_root_at_slot(&beacon_chain, slot)?;
 
-    let json: String = serde_json::to_string(&root)
-        .map_err(|e| ApiError::ServerError(format!("Unable to serialize root: {:?}", e)))?;
-
-    Ok(success_response(Body::from(json)))
+    ResponseBuilder::new(&req)?.body(&root)
 }
 
 /// HTTP handler to return the highest finalized slot.
-pub fn get_latest_finalized_checkpoint<T: BeaconChainTypes + 'static>(
+pub fn get_current_finalized_checkpoint<T: BeaconChainTypes + 'static>(
     req: Request<Body>,
 ) -> ApiResult {
-    let beacon_chain = req
-        .extensions()
-        .get::<Arc<BeaconChain<T>>>()
-        .ok_or_else(|| ApiError::ServerError("Beacon chain extension missing".to_string()))?;
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
+    let head_state = beacon_chain.head().beacon_state;
 
-    let checkpoint = beacon_chain
-        .head()
-        .beacon_state
-        .finalized_checkpoint
-        .clone();
+    let checkpoint = head_state.finalized_checkpoint.clone();
 
-    let json: String = serde_json::to_string(&checkpoint)
-        .map_err(|e| ApiError::ServerError(format!("Unable to serialize checkpoint: {:?}", e)))?;
-
-    Ok(success_response(Body::from(json)))
+    ResponseBuilder::new(&req)?.body(&checkpoint)
+}
+
+/// HTTP handler to return a `BeaconState` at the genesis block.
+pub fn get_genesis_state<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
+
+    let (_root, state) = state_at_slot(&beacon_chain, Slot::new(0))?;
+
+    ResponseBuilder::new(&req)?.body(&state)
 }

beacon_node/rest_api/src/config.rs

@@ -16,7 +16,7 @@ pub struct Config {
 impl Default for Config {
     fn default() -> Self {
         Config {
-            enabled: true, // rest_api enabled by default
+            enabled: true,
             listen_address: Ipv4Addr::new(127, 0, 0, 1),
             port: 5052,
         }
@@ -25,8 +25,8 @@ impl Default for Config {
 
 impl Config {
     pub fn apply_cli_args(&mut self, args: &ArgMatches) -> Result<(), &'static str> {
-        if args.is_present("api") {
-            self.enabled = true;
+        if args.is_present("no-api") {
+            self.enabled = false;
         }
 
         if let Some(rpc_address) = args.value_of("api-address") {

beacon_node/rest_api/src/error.rs

@@ -0,0 +1,86 @@
+use crate::BoxFut;
+use hyper::{Body, Response, StatusCode};
+use std::error::Error as StdError;
+
+#[derive(PartialEq, Debug, Clone)]
+pub enum ApiError {
+    MethodNotAllowed(String),
+    ServerError(String),
+    NotImplemented(String),
+    BadRequest(String),
+    NotFound(String),
+    UnsupportedType(String),
+    ImATeapot(String),       // Just in case.
+    ProcessingError(String), // A 202 error, for when a block/attestation cannot be processed, but still transmitted.
+}
+
+pub type ApiResult = Result<Response<Body>, ApiError>;
+
+impl ApiError {
+    pub fn status_code(self) -> (StatusCode, String) {
+        match self {
+            ApiError::MethodNotAllowed(desc) => (StatusCode::METHOD_NOT_ALLOWED, desc),
+            ApiError::ServerError(desc) => (StatusCode::INTERNAL_SERVER_ERROR, desc),
+            ApiError::NotImplemented(desc) => (StatusCode::NOT_IMPLEMENTED, desc),
+            ApiError::BadRequest(desc) => (StatusCode::BAD_REQUEST, desc),
+            ApiError::NotFound(desc) => (StatusCode::NOT_FOUND, desc),
+            ApiError::UnsupportedType(desc) => (StatusCode::UNSUPPORTED_MEDIA_TYPE, desc),
+            ApiError::ImATeapot(desc) => (StatusCode::IM_A_TEAPOT, desc),
+            ApiError::ProcessingError(desc) => (StatusCode::ACCEPTED, desc),
+        }
+    }
+}
+
+impl Into<Response<Body>> for ApiError {
+    fn into(self) -> Response<Body> {
+        let status_code = self.status_code();
+        Response::builder()
+            .status(status_code.0)
+            .header("content-type", "text/plain; charset=utf-8")
+            .body(Body::from(status_code.1))
+            .expect("Response should always be created.")
+    }
+}
+
+impl Into<BoxFut> for ApiError {
+    fn into(self) -> BoxFut {
+        Box::new(futures::future::err(self))
+    }
+}
+
+impl From<store::Error> for ApiError {
+    fn from(e: store::Error) -> ApiError {
+        ApiError::ServerError(format!("Database error: {:?}", e))
+    }
+}
+
+impl From<types::BeaconStateError> for ApiError {
+    fn from(e: types::BeaconStateError) -> ApiError {
+        ApiError::ServerError(format!("BeaconState error: {:?}", e))
+    }
+}
+
+impl From<state_processing::per_slot_processing::Error> for ApiError {
+    fn from(e: state_processing::per_slot_processing::Error) -> ApiError {
+        ApiError::ServerError(format!("PerSlotProcessing error: {:?}", e))
+    }
+}
+
+impl From<hyper::error::Error> for ApiError {
+    fn from(e: hyper::error::Error) -> ApiError {
+        ApiError::ServerError(format!("Networking error: {:?}", e))
+    }
+}
+
+impl StdError for ApiError {
+    fn cause(&self) -> Option<&dyn StdError> {
+        None
+    }
+}
+
+impl std::fmt::Display for ApiError {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        let status = self.clone().status_code();
+        write!(f, "{:?}: {:?}", status.0, status.1)
+    }
+}

beacon_node/rest_api/src/helpers.rs

@@ -1,12 +1,20 @@
 use crate::{ApiError, ApiResult};
 use beacon_chain::{BeaconChain, BeaconChainTypes};
 use bls::PublicKey;
+use eth2_libp2p::{PubsubMessage, Topic};
+use eth2_libp2p::{
+    BEACON_ATTESTATION_TOPIC, BEACON_BLOCK_TOPIC, TOPIC_ENCODING_POSTFIX, TOPIC_PREFIX,
+};
 use hex;
-use hyper::{Body, Request, StatusCode};
-use serde::de::value::StringDeserializer;
-use serde_json::Deserializer;
+use http::header;
+use hyper::{Body, Request};
+use network::NetworkMessage;
+use parking_lot::RwLock;
+use ssz::Encode;
+use std::sync::Arc;
 use store::{iter::AncestorIter, Store};
-use types::{BeaconState, EthSpec, Hash256, RelativeEpoch, Slot};
+use tokio::sync::mpsc;
+use types::{Attestation, BeaconBlock, BeaconState, EthSpec, Hash256, RelativeEpoch, Slot};
 
 /// Parse a slot from a `0x` preixed string.
 ///
@@ -15,7 +23,22 @@ pub fn parse_slot(string: &str) -> Result<Slot, ApiError> {
     string
         .parse::<u64>()
         .map(Slot::from)
-        .map_err(|e| ApiError::InvalidQueryParams(format!("Unable to parse slot: {:?}", e)))
+        .map_err(|e| ApiError::BadRequest(format!("Unable to parse slot: {:?}", e)))
+}
+
+/// Checks the provided request to ensure that the `content-type` header.
+///
+/// The content-type header should either be omitted, in which case JSON is assumed, or it should
+/// explicity specify `application/json`. If anything else is provided, an error is returned.
+pub fn check_content_type_for_json(req: &Request<Body>) -> Result<(), ApiError> {
+    match req.headers().get(header::CONTENT_TYPE) {
+        Some(h) if h == "application/json" => Ok(()),
+        Some(h) => Err(ApiError::BadRequest(format!(
+            "The provided content-type {:?} is not available, this endpoint only supports json.",
+            h
+        ))),
+        _ => Ok(()),
+    }
 }
 
 /// Parse a root from a `0x` preixed string.
@@ -28,9 +51,9 @@ pub fn parse_root(string: &str) -> Result<Hash256, ApiError> {
         let trimmed = string.trim_start_matches(PREFIX);
         trimmed
             .parse()
-            .map_err(|e| ApiError::InvalidQueryParams(format!("Unable to parse root: {:?}", e)))
+            .map_err(|e| ApiError::BadRequest(format!("Unable to parse root: {:?}", e)))
     } else {
-        Err(ApiError::InvalidQueryParams(
+        Err(ApiError::BadRequest(
             "Root must have a  '0x' prefix".to_string(),
         ))
     }
@@ -41,13 +64,13 @@ pub fn parse_pubkey(string: &str) -> Result<PublicKey, ApiError> {
     const PREFIX: &str = "0x";
     if string.starts_with(PREFIX) {
         let pubkey_bytes = hex::decode(string.trim_start_matches(PREFIX))
-            .map_err(|e| ApiError::InvalidQueryParams(format!("Invalid hex string: {:?}", e)))?;
+            .map_err(|e| ApiError::BadRequest(format!("Invalid hex string: {:?}", e)))?;
         let pubkey = PublicKey::from_bytes(pubkey_bytes.as_slice()).map_err(|e| {
-            ApiError::InvalidQueryParams(format!("Unable to deserialize public key: {:?}.", e))
+            ApiError::BadRequest(format!("Unable to deserialize public key: {:?}.", e))
         })?;
         return Ok(pubkey);
     } else {
-        return Err(ApiError::InvalidQueryParams(
+        return Err(ApiError::BadRequest(
             "Public key must have a  '0x' prefix".to_string(),
         ));
     }
@@ -110,8 +133,8 @@ pub fn state_root_at_slot<T: BeaconChainTypes>(
 ) -> Result<Hash256, ApiError> {
     let head_state = &beacon_chain.head().beacon_state;
     let current_slot = beacon_chain
-        .read_slot_clock()
-        .ok_or_else(|| ApiError::ServerError("Unable to read slot clock".to_string()))?;
+        .slot()
+        .map_err(|_| ApiError::ServerError("Unable to read slot clock".to_string()))?;
 
     // There are four scenarios when obtaining a state for a given slot:
     //
@@ -124,7 +147,7 @@ pub fn state_root_at_slot<T: BeaconChainTypes>(
         //
         // We could actually speculate about future state roots by skipping slots, however that's
         // likely to cause confusion for API users.
-        Err(ApiError::InvalidQueryParams(format!(
+        Err(ApiError::BadRequest(format!(
             "Requested slot {} is past the current slot {}",
             slot, current_slot
         )))
@@ -171,6 +194,78 @@ pub fn implementation_pending_response(_req: Request<Body>) -> ApiResult {
     ))
 }
 
+pub fn get_beacon_chain_from_request<T: BeaconChainTypes + 'static>(
+    req: &Request<Body>,
+) -> Result<(Arc<BeaconChain<T>>), ApiError> {
+    // Get beacon state
+    let beacon_chain = req
+        .extensions()
+        .get::<Arc<BeaconChain<T>>>()
+        .ok_or_else(|| ApiError::ServerError("Beacon chain extension missing".into()))?;
+
+    Ok(beacon_chain.clone())
+}
+
+pub fn get_logger_from_request(req: &Request<Body>) -> slog::Logger {
+    let log = req
+        .extensions()
+        .get::<slog::Logger>()
+        .expect("Should always get the logger from the request, since we put it in there.");
+    log.to_owned()
+}
+
+pub fn publish_beacon_block_to_network<T: BeaconChainTypes + 'static>(
+    chan: Arc<RwLock<mpsc::UnboundedSender<NetworkMessage>>>,
+    block: BeaconBlock<T::EthSpec>,
+) -> Result<(), ApiError> {
+    // create the network topic to send on
+    let topic_string = format!(
+        "/{}/{}/{}",
+        TOPIC_PREFIX, BEACON_BLOCK_TOPIC, TOPIC_ENCODING_POSTFIX
+    );
+    let topic = Topic::new(topic_string);
+    let message = PubsubMessage::Block(block.as_ssz_bytes());
+
+    // Publish the block to the p2p network via gossipsub.
+    if let Err(e) = chan.write().try_send(NetworkMessage::Publish {
+        topics: vec![topic],
+        message,
+    }) {
+        return Err(ApiError::ServerError(format!(
+            "Unable to send new block to network: {:?}",
+            e
+        )));
+    }
+
+    Ok(())
+}
+
+pub fn publish_attestation_to_network<T: BeaconChainTypes + 'static>(
+    chan: Arc<RwLock<mpsc::UnboundedSender<NetworkMessage>>>,
+    attestation: Attestation<T::EthSpec>,
+) -> Result<(), ApiError> {
+    // create the network topic to send on
+    let topic_string = format!(
+        "/{}/{}/{}",
+        TOPIC_PREFIX, BEACON_ATTESTATION_TOPIC, TOPIC_ENCODING_POSTFIX
+    );
+    let topic = Topic::new(topic_string);
+    let message = PubsubMessage::Attestation(attestation.as_ssz_bytes());
+
+    // Publish the attestation to the p2p network via gossipsub.
+    if let Err(e) = chan.write().try_send(NetworkMessage::Publish {
+        topics: vec![topic],
+        message,
+    }) {
+        return Err(ApiError::ServerError(format!(
+            "Unable to send new attestation to network: {:?}",
+            e
+        )));
+    }
+
+    Ok(())
+}
+
 #[cfg(test)]
 mod test {
     use super::*;

beacon_node/rest_api/src/lib.rs

@@ -1,76 +1,192 @@
 #[macro_use]
+mod macros;
+#[macro_use]
 extern crate lazy_static;
 extern crate network as client_network;
 
 mod beacon;
 mod config;
+mod error;
 mod helpers;
 mod metrics;
 mod network;
 mod node;
+mod response_builder;
 mod spec;
 mod url_query;
 mod validator;
 
 use beacon_chain::{BeaconChain, BeaconChainTypes};
+use client_network::NetworkMessage;
 use client_network::Service as NetworkService;
+use error::{ApiError, ApiResult};
+use eth2_config::Eth2Config;
+use futures::future::IntoFuture;
 use hyper::rt::Future;
-use hyper::service::service_fn_ok;
-use hyper::{Body, Method, Response, Server, StatusCode};
+use hyper::service::Service;
+use hyper::{Body, Method, Request, Response, Server};
+use parking_lot::RwLock;
 use slog::{info, o, warn};
 use std::ops::Deref;
 use std::path::PathBuf;
 use std::sync::Arc;
 use tokio::runtime::TaskExecutor;
+use tokio::sync::mpsc;
 use url_query::UrlQuery;
 
 pub use beacon::{BlockResponse, HeadResponse, StateResponse};
 pub use config::Config as ApiConfig;
 
-#[derive(PartialEq, Debug)]
-pub enum ApiError {
-    MethodNotAllowed(String),
-    ServerError(String),
-    NotImplemented(String),
-    InvalidQueryParams(String),
-    NotFound(String),
-    ImATeapot(String), // Just in case.
+type BoxFut = Box<dyn Future<Item = Response<Body>, Error = ApiError> + Send>;
+
+pub struct ApiService<T: BeaconChainTypes + 'static> {
+    log: slog::Logger,
+    beacon_chain: Arc<BeaconChain<T>>,
+    db_path: DBPath,
+    network_service: Arc<NetworkService<T>>,
+    network_channel: Arc<RwLock<mpsc::UnboundedSender<NetworkMessage>>>,
+    eth2_config: Arc<Eth2Config>,
 }
 
-pub type ApiResult = Result<Response<Body>, ApiError>;
+fn into_boxfut<F: IntoFuture + 'static>(item: F) -> BoxFut
+where
+    F: IntoFuture<Item = Response<Body>, Error = ApiError>,
+    F::Future: Send,
+{
+    Box::new(item.into_future())
+}
 
-impl Into<Response<Body>> for ApiError {
-    fn into(self) -> Response<Body> {
-        let status_code: (StatusCode, String) = match self {
-            ApiError::MethodNotAllowed(desc) => (StatusCode::METHOD_NOT_ALLOWED, desc),
-            ApiError::ServerError(desc) => (StatusCode::INTERNAL_SERVER_ERROR, desc),
-            ApiError::NotImplemented(desc) => (StatusCode::NOT_IMPLEMENTED, desc),
-            ApiError::InvalidQueryParams(desc) => (StatusCode::BAD_REQUEST, desc),
-            ApiError::NotFound(desc) => (StatusCode::NOT_FOUND, desc),
-            ApiError::ImATeapot(desc) => (StatusCode::IM_A_TEAPOT, desc),
+impl<T: BeaconChainTypes> Service for ApiService<T> {
+    type ReqBody = Body;
+    type ResBody = Body;
+    type Error = ApiError;
+    type Future = BoxFut;
+
+    fn call(&mut self, mut req: Request<Body>) -> Self::Future {
+        metrics::inc_counter(&metrics::REQUEST_COUNT);
+        let timer = metrics::start_timer(&metrics::REQUEST_RESPONSE_TIME);
+
+        // Add all the useful bits into the request, so that we can pull them out in the individual
+        // functions.
+        req.extensions_mut()
+            .insert::<slog::Logger>(self.log.clone());
+        req.extensions_mut()
+            .insert::<Arc<BeaconChain<T>>>(self.beacon_chain.clone());
+        req.extensions_mut().insert::<DBPath>(self.db_path.clone());
+        req.extensions_mut()
+            .insert::<Arc<NetworkService<T>>>(self.network_service.clone());
+        req.extensions_mut()
+            .insert::<Arc<RwLock<mpsc::UnboundedSender<NetworkMessage>>>>(
+                self.network_channel.clone(),
+            );
+        req.extensions_mut()
+            .insert::<Arc<Eth2Config>>(self.eth2_config.clone());
+
+        let path = req.uri().path().to_string();
+
+        // Route the request to the correct handler.
+        let result = match (req.method(), path.as_ref()) {
+            // Methods for Client
+            (&Method::GET, "/node/version") => into_boxfut(node::get_version(req)),
+            (&Method::GET, "/node/genesis_time") => into_boxfut(node::get_genesis_time::<T>(req)),
+            (&Method::GET, "/node/syncing") => {
+                into_boxfut(helpers::implementation_pending_response(req))
+            }
+
+            // Methods for Network
+            (&Method::GET, "/network/enr") => into_boxfut(network::get_enr::<T>(req)),
+            (&Method::GET, "/network/peer_count") => into_boxfut(network::get_peer_count::<T>(req)),
+            (&Method::GET, "/network/peer_id") => into_boxfut(network::get_peer_id::<T>(req)),
+            (&Method::GET, "/network/peers") => into_boxfut(network::get_peer_list::<T>(req)),
+            (&Method::GET, "/network/listen_port") => {
+                into_boxfut(network::get_listen_port::<T>(req))
+            }
+            (&Method::GET, "/network/listen_addresses") => {
+                into_boxfut(network::get_listen_addresses::<T>(req))
+            }
+
+            // Methods for Beacon Node
+            (&Method::GET, "/beacon/head") => into_boxfut(beacon::get_head::<T>(req)),
+            (&Method::GET, "/beacon/block") => into_boxfut(beacon::get_block::<T>(req)),
+            (&Method::GET, "/beacon/block_root") => into_boxfut(beacon::get_block_root::<T>(req)),
+            (&Method::GET, "/beacon/blocks") => {
+                into_boxfut(helpers::implementation_pending_response(req))
+            }
+            (&Method::GET, "/beacon/fork") => into_boxfut(beacon::get_fork::<T>(req)),
+            (&Method::GET, "/beacon/attestations") => {
+                into_boxfut(helpers::implementation_pending_response(req))
+            }
+            (&Method::GET, "/beacon/attestations/pending") => {
+                into_boxfut(helpers::implementation_pending_response(req))
+            }
+
+            (&Method::GET, "/beacon/validators") => into_boxfut(beacon::get_validators::<T>(req)),
+            (&Method::GET, "/beacon/validators/indicies") => {
+                into_boxfut(helpers::implementation_pending_response(req))
+            }
+            (&Method::GET, "/beacon/validators/pubkeys") => {
+                into_boxfut(helpers::implementation_pending_response(req))
+            }
+
+            // Methods for Validator
+            (&Method::GET, "/beacon/validator/duties") => {
+                into_boxfut(validator::get_validator_duties::<T>(req))
+            }
+            (&Method::GET, "/beacon/validator/block") => {
+                into_boxfut(validator::get_new_beacon_block::<T>(req))
+            }
+            (&Method::POST, "/beacon/validator/block") => validator::publish_beacon_block::<T>(req),
+            (&Method::GET, "/beacon/validator/attestation") => {
+                into_boxfut(validator::get_new_attestation::<T>(req))
+            }
+            (&Method::POST, "/beacon/validator/attestation") => {
+                validator::publish_attestation::<T>(req)
+            }
+
+            (&Method::GET, "/beacon/state") => into_boxfut(beacon::get_state::<T>(req)),
+            (&Method::GET, "/beacon/state_root") => into_boxfut(beacon::get_state_root::<T>(req)),
+            (&Method::GET, "/beacon/state/current_finalized_checkpoint") => {
+                into_boxfut(beacon::get_current_finalized_checkpoint::<T>(req))
+            }
+            (&Method::GET, "/beacon/state/genesis") => {
+                into_boxfut(beacon::get_genesis_state::<T>(req))
+            }
+            //TODO: Add aggreggate/filtered state lookups here, e.g. /beacon/validators/balances
+
+            // Methods for bootstrap and checking configuration
+            (&Method::GET, "/spec") => into_boxfut(spec::get_spec::<T>(req)),
+            (&Method::GET, "/spec/slots_per_epoch") => {
+                into_boxfut(spec::get_slots_per_epoch::<T>(req))
+            }
+            (&Method::GET, "/spec/deposit_contract") => {
+                into_boxfut(helpers::implementation_pending_response(req))
+            }
+            (&Method::GET, "/spec/eth2_config") => into_boxfut(spec::get_eth2_config::<T>(req)),
+
+            (&Method::GET, "/metrics") => into_boxfut(metrics::get_prometheus::<T>(req)),
+
+            _ => Box::new(futures::future::err(ApiError::NotFound(
+                "Request path and/or method not found.".to_owned(),
+            ))),
         };
-        Response::builder()
-            .status(status_code.0)
-            .body(Body::from(status_code.1))
-            .expect("Response should always be created.")
-    }
-}
 
-impl From<store::Error> for ApiError {
-    fn from(e: store::Error) -> ApiError {
-        ApiError::ServerError(format!("Database error: {:?}", e))
-    }
-}
+        let response = match result.wait() {
+            // Return the `hyper::Response`.
+            Ok(response) => {
+                metrics::inc_counter(&metrics::SUCCESS_COUNT);
+                slog::debug!(self.log, "Request successful: {:?}", path);
+                response
+            }
+            // Map the `ApiError` into `hyper::Response`.
+            Err(e) => {
+                slog::debug!(self.log, "Request failure: {:?}", path);
+                e.into()
+            }
+        };
 
-impl From<types::BeaconStateError> for ApiError {
-    fn from(e: types::BeaconStateError) -> ApiError {
-        ApiError::ServerError(format!("BeaconState error: {:?}", e))
-    }
-}
+        metrics::stop_timer(timer);
 
-impl From<state_processing::per_slot_processing::Error> for ApiError {
-    fn from(e: state_processing::per_slot_processing::Error) -> ApiError {
-        ApiError::ServerError(format!("PerSlotProcessing error: {:?}", e))
+        Box::new(futures::future::ok(response))
     }
 }
 
@@ -79,7 +195,9 @@ pub fn start_server<T: BeaconChainTypes>(
     executor: &TaskExecutor,
     beacon_chain: Arc<BeaconChain<T>>,
     network_service: Arc<NetworkService<T>>,
+    network_chan: mpsc::UnboundedSender<NetworkMessage>,
     db_path: PathBuf,
+    eth2_config: Eth2Config,
     log: &slog::Logger,
 ) -> Result<exit_future::Signal, hyper::Error> {
     let log = log.new(o!("Service" => "Api"));
@@ -101,113 +219,16 @@ pub fn start_server<T: BeaconChainTypes>(
     // Clone our stateful objects, for use in service closure.
     let server_log = log.clone();
     let server_bc = beacon_chain.clone();
+    let eth2_config = Arc::new(eth2_config);
 
-    let service = move || {
-        let log = server_log.clone();
-        let beacon_chain = server_bc.clone();
-        let db_path = db_path.clone();
-        let network_service = network_service.clone();
-
-        // Create a simple handler for the router, inject our stateful objects into the request.
-        service_fn_ok(move |mut req| {
-            metrics::inc_counter(&metrics::REQUEST_COUNT);
-            let timer = metrics::start_timer(&metrics::REQUEST_RESPONSE_TIME);
-
-            req.extensions_mut().insert::<slog::Logger>(log.clone());
-            req.extensions_mut()
-                .insert::<Arc<BeaconChain<T>>>(beacon_chain.clone());
-            req.extensions_mut().insert::<DBPath>(db_path.clone());
-            req.extensions_mut()
-                .insert::<Arc<NetworkService<T>>>(network_service.clone());
-
-            let path = req.uri().path().to_string();
-
-            // Route the request to the correct handler.
-            let result = match (req.method(), path.as_ref()) {
-                // Methods for Beacon Node
-                //TODO: Remove?
-                //(&Method::GET, "/beacon/best_slot") => beacon::get_best_slot::<T>(req),
-                (&Method::GET, "/beacon/head") => beacon::get_head::<T>(req),
-                (&Method::GET, "/beacon/block") => beacon::get_block::<T>(req),
-                (&Method::GET, "/beacon/blocks") => helpers::implementation_pending_response(req),
-                //TODO Is the below replaced by finalized_checkpoint?
-                (&Method::GET, "/beacon/chainhead") => {
-                    helpers::implementation_pending_response(req)
-                }
-                (&Method::GET, "/beacon/block_root") => beacon::get_block_root::<T>(req),
-                (&Method::GET, "/beacon/latest_finalized_checkpoint") => {
-                    beacon::get_latest_finalized_checkpoint::<T>(req)
-                }
-                (&Method::GET, "/beacon/state") => beacon::get_state::<T>(req),
-                (&Method::GET, "/beacon/state_root") => beacon::get_state_root::<T>(req),
-
-                //TODO: Add aggreggate/filtered state lookups here, e.g. /beacon/validators/balances
-
-                // Methods for Client
-                (&Method::GET, "/metrics") => metrics::get_prometheus::<T>(req),
-                (&Method::GET, "/network/enr") => network::get_enr::<T>(req),
-                (&Method::GET, "/network/peer_count") => network::get_peer_count::<T>(req),
-                (&Method::GET, "/network/peer_id") => network::get_peer_id::<T>(req),
-                (&Method::GET, "/network/peers") => network::get_peer_list::<T>(req),
-                (&Method::GET, "/network/listen_port") => network::get_listen_port::<T>(req),
-                (&Method::GET, "/network/listen_addresses") => {
-                    network::get_listen_addresses::<T>(req)
-                }
-                (&Method::GET, "/node/version") => node::get_version(req),
-                (&Method::GET, "/node/genesis_time") => node::get_genesis_time::<T>(req),
-                (&Method::GET, "/node/deposit_contract") => {
-                    helpers::implementation_pending_response(req)
-                }
-                (&Method::GET, "/node/syncing") => helpers::implementation_pending_response(req),
-                (&Method::GET, "/node/fork") => helpers::implementation_pending_response(req),
-
-                // Methods for Network
-                (&Method::GET, "/network/enr") => network::get_enr::<T>(req),
-                (&Method::GET, "/network/peer_count") => network::get_peer_count::<T>(req),
-                (&Method::GET, "/network/peer_id") => network::get_peer_id::<T>(req),
-                (&Method::GET, "/network/peers") => network::get_peer_list::<T>(req),
-                (&Method::GET, "/network/listen_addresses") => {
-                    network::get_listen_addresses::<T>(req)
-                }
-
-                // Methods for Validator
-                (&Method::GET, "/validator/duties") => validator::get_validator_duties::<T>(req),
-                (&Method::GET, "/validator/block") => helpers::implementation_pending_response(req),
-                (&Method::POST, "/validator/block") => {
-                    helpers::implementation_pending_response(req)
-                }
-                (&Method::GET, "/validator/attestation") => {
-                    helpers::implementation_pending_response(req)
-                }
-                (&Method::POST, "/validator/attestation") => {
-                    helpers::implementation_pending_response(req)
-                }
-
-                (&Method::GET, "/spec") => spec::get_spec::<T>(req),
-                (&Method::GET, "/spec/slots_per_epoch") => spec::get_slots_per_epoch::<T>(req),
-
-                _ => Err(ApiError::NotFound(
-                    "Request path and/or method not found.".to_owned(),
-                )),
-            };
-
-            let response = match result {
-                // Return the `hyper::Response`.
-                Ok(response) => {
-                    metrics::inc_counter(&metrics::SUCCESS_COUNT);
-                    slog::debug!(log, "Request successful: {:?}", path);
-                    response
-                }
-                // Map the `ApiError` into `hyper::Response`.
-                Err(e) => {
-                    slog::debug!(log, "Request failure: {:?}", path);
-                    e.into()
-                }
-            };
-
-            metrics::stop_timer(timer);
-
-            response
+    let service = move || -> futures::future::FutureResult<ApiService<T>, String> {
+        futures::future::ok(ApiService {
+            log: server_log.clone(),
+            beacon_chain: server_bc.clone(),
+            db_path: db_path.clone(),
+            network_service: network_service.clone(),
+            network_channel: Arc::new(RwLock::new(network_chan.clone())),
+            eth2_config: eth2_config.clone(),
         })
     };
 
@@ -217,16 +238,16 @@ pub fn start_server<T: BeaconChainTypes>(
         .with_graceful_shutdown(server_exit)
         .map_err(move |e| {
             warn!(
-                log_clone,
-                "API failed to start, Unable to bind"; "address" => format!("{:?}", e)
+            log_clone,
+            "API failed to start, Unable to bind"; "address" => format!("{:?}", e)
             )
         });
 
     info!(
-        log,
-        "REST API started";
-        "address" => format!("{}", config.listen_address),
-        "port" => config.port,
+    log,
+    "REST API started";
+    "address" => format!("{}", config.listen_address),
+    "port" => config.port,
     );
 
     executor.spawn(server);
@@ -234,13 +255,6 @@ pub fn start_server<T: BeaconChainTypes>(
     Ok(exit_signal)
 }
 
-fn success_response(body: Body) -> Response<Body> {
-    Response::builder()
-        .status(StatusCode::OK)
-        .body(body)
-        .expect("We should always be able to make response from the success body.")
-}
-
 #[derive(Clone)]
 pub struct DBPath(PathBuf);
 

beacon_node/rest_api/src/macros.rs

@@ -0,0 +1,13 @@
+macro_rules! try_future {
+    ($expr:expr) => {
+        match $expr {
+            core::result::Result::Ok(val) => val,
+            core::result::Result::Err(err) => {
+                return Box::new(futures::future::err(std::convert::From::from(err)))
+            }
+        }
+    };
+    ($expr:expr,) => {
+        $crate::try_future!($expr)
+    };
+}

beacon_node/rest_api/src/metrics.rs

@@ -1,8 +1,9 @@
-use crate::{success_response, ApiError, ApiResult, DBPath};
-use beacon_chain::{BeaconChain, BeaconChainTypes};
+use crate::helpers::get_beacon_chain_from_request;
+use crate::response_builder::ResponseBuilder;
+use crate::{ApiError, ApiResult, DBPath};
+use beacon_chain::BeaconChainTypes;
 use hyper::{Body, Request};
 use prometheus::{Encoder, TextEncoder};
-use std::sync::Arc;
 
 pub use lighthouse_metrics::*;
 
@@ -30,10 +31,7 @@ pub fn get_prometheus<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiR
     let mut buffer = vec![];
     let encoder = TextEncoder::new();
 
-    let beacon_chain = req
-        .extensions()
-        .get::<Arc<BeaconChain<T>>>()
-        .ok_or_else(|| ApiError::ServerError("Beacon chain extension missing".to_string()))?;
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
     let db_path = req
         .extensions()
         .get::<DBPath>()
@@ -64,6 +62,6 @@ pub fn get_prometheus<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiR
         .unwrap();
 
     String::from_utf8(buffer)
-        .map(|string| success_response(Body::from(string)))
-        .map_err(|e| ApiError::ServerError(format!("Failed to encode prometheus info: {:?}", e)))
+        .map(|string| ResponseBuilder::new(&req)?.body_text(string))
+        .map_err(|e| ApiError::ServerError(format!("Failed to encode prometheus info: {:?}", e)))?
 }

beacon_node/rest_api/src/network.rs

@@ -1,108 +1,78 @@
-use crate::{success_response, ApiError, ApiResult, NetworkService};
+use crate::error::ApiResult;
+use crate::response_builder::ResponseBuilder;
+use crate::NetworkService;
 use beacon_chain::BeaconChainTypes;
-use eth2_libp2p::{Enr, Multiaddr, PeerId};
+use eth2_libp2p::{Multiaddr, PeerId};
 use hyper::{Body, Request};
 use std::sync::Arc;
 
-/// HTTP handle to return the list of libp2p multiaddr the client is listening on.
+/// HTTP handler to return the list of libp2p multiaddr the client is listening on.
 ///
 /// Returns a list of `Multiaddr`, serialized according to their `serde` impl.
 pub fn get_listen_addresses<T: BeaconChainTypes>(req: Request<Body>) -> ApiResult {
     let network = req
         .extensions()
         .get::<Arc<NetworkService<T>>>()
-        .ok_or_else(|| ApiError::ServerError("NetworkService extension missing".to_string()))?;
-
+        .expect("The network service should always be there, we put it there");
     let multiaddresses: Vec<Multiaddr> = network.listen_multiaddrs();
-
-    Ok(success_response(Body::from(
-        serde_json::to_string(&multiaddresses)
-            .map_err(|e| ApiError::ServerError(format!("Unable to serialize Enr: {:?}", e)))?,
-    )))
+    ResponseBuilder::new(&req)?.body_no_ssz(&multiaddresses)
 }
 
-/// HTTP handle to return the list of libp2p multiaddr the client is listening on.
+/// HTTP handler to return the network port the client is listening on.
 ///
-/// Returns a list of `Multiaddr`, serialized according to their `serde` impl.
+/// Returns the TCP port number in its plain form (which is also valid JSON serialization)
 pub fn get_listen_port<T: BeaconChainTypes>(req: Request<Body>) -> ApiResult {
     let network = req
         .extensions()
         .get::<Arc<NetworkService<T>>>()
-        .ok_or_else(|| ApiError::ServerError("NetworkService extension missing".to_string()))?;
-
-    Ok(success_response(Body::from(
-        serde_json::to_string(&network.listen_port())
-            .map_err(|e| ApiError::ServerError(format!("Unable to serialize port: {:?}", e)))?,
-    )))
+        .expect("The network service should always be there, we put it there")
+        .clone();
+    ResponseBuilder::new(&req)?.body(&network.listen_port())
 }
 
-/// HTTP handle to return the Discv5 ENR from the client's libp2p service.
+/// HTTP handler to return the Discv5 ENR from the client's libp2p service.
 ///
 /// ENR is encoded as base64 string.
 pub fn get_enr<T: BeaconChainTypes>(req: Request<Body>) -> ApiResult {
     let network = req
         .extensions()
         .get::<Arc<NetworkService<T>>>()
-        .ok_or_else(|| ApiError::ServerError("NetworkService extension missing".to_string()))?;
-
-    let enr: Enr = network.local_enr();
-
-    Ok(success_response(Body::from(
-        serde_json::to_string(&enr.to_base64())
-            .map_err(|e| ApiError::ServerError(format!("Unable to serialize Enr: {:?}", e)))?,
-    )))
+        .expect("The network service should always be there, we put it there");
+    ResponseBuilder::new(&req)?.body_no_ssz(&network.local_enr().to_base64())
 }
 
-/// HTTP handle to return the `PeerId` from the client's libp2p service.
+/// HTTP handler to return the `PeerId` from the client's libp2p service.
 ///
 /// PeerId is encoded as base58 string.
 pub fn get_peer_id<T: BeaconChainTypes>(req: Request<Body>) -> ApiResult {
     let network = req
         .extensions()
         .get::<Arc<NetworkService<T>>>()
-        .ok_or_else(|| ApiError::ServerError("NetworkService extension missing".to_string()))?;
-
-    let peer_id: PeerId = network.local_peer_id();
-
-    Ok(success_response(Body::from(
-        serde_json::to_string(&peer_id.to_base58())
-            .map_err(|e| ApiError::ServerError(format!("Unable to serialize Enr: {:?}", e)))?,
-    )))
+        .expect("The network service should always be there, we put it there");
+    ResponseBuilder::new(&req)?.body_no_ssz(&network.local_peer_id().to_base58())
 }
 
-/// HTTP handle to return the number of peers connected in the client's libp2p service.
+/// HTTP handler to return the number of peers connected in the client's libp2p service.
 pub fn get_peer_count<T: BeaconChainTypes>(req: Request<Body>) -> ApiResult {
     let network = req
         .extensions()
         .get::<Arc<NetworkService<T>>>()
-        .ok_or_else(|| ApiError::ServerError("NetworkService extension missing".to_string()))?;
-
-    let connected_peers: usize = network.connected_peers();
-
-    Ok(success_response(Body::from(
-        serde_json::to_string(&connected_peers)
-            .map_err(|e| ApiError::ServerError(format!("Unable to serialize Enr: {:?}", e)))?,
-    )))
+        .expect("The network service should always be there, we put it there");
+    ResponseBuilder::new(&req)?.body(&network.connected_peers())
 }
 
-/// HTTP handle to return the list of peers connected to the client's libp2p service.
+/// HTTP handler to return the list of peers connected to the client's libp2p service.
 ///
 /// Peers are presented as a list of `PeerId::to_string()`.
 pub fn get_peer_list<T: BeaconChainTypes>(req: Request<Body>) -> ApiResult {
     let network = req
         .extensions()
         .get::<Arc<NetworkService<T>>>()
-        .ok_or_else(|| ApiError::ServerError("NetworkService extension missing".to_string()))?;
-
+        .expect("The network service should always be there, we put it there");
     let connected_peers: Vec<String> = network
         .connected_peer_set()
         .iter()
         .map(PeerId::to_string)
         .collect();
-
-    Ok(success_response(Body::from(
-        serde_json::to_string(&connected_peers).map_err(|e| {
-            ApiError::ServerError(format!("Unable to serialize Vec<PeerId>: {:?}", e))
-        })?,
-    )))
+    ResponseBuilder::new(&req)?.body_no_ssz(&connected_peers)
 }

beacon_node/rest_api/src/node.rs

@@ -1,25 +1,17 @@
-use crate::{success_response, ApiResult};
-use beacon_chain::{BeaconChain, BeaconChainTypes};
+use crate::helpers::get_beacon_chain_from_request;
+use crate::response_builder::ResponseBuilder;
+use crate::ApiResult;
+use beacon_chain::BeaconChainTypes;
 use hyper::{Body, Request};
-use std::sync::Arc;
 use version;
 
 /// Read the version string from the current Lighthouse build.
-pub fn get_version(_req: Request<Body>) -> ApiResult {
-    let body = Body::from(
-        serde_json::to_string(&version::version())
-            .expect("Version should always be serialializable as JSON."),
-    );
-    Ok(success_response(body))
+pub fn get_version(req: Request<Body>) -> ApiResult {
+    ResponseBuilder::new(&req)?.body_no_ssz(&version::version())
 }
 
 /// Read the genesis time from the current beacon chain state.
 pub fn get_genesis_time<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
-    let beacon_chain = req.extensions().get::<Arc<BeaconChain<T>>>().unwrap();
-    let gen_time: u64 = beacon_chain.head().beacon_state.genesis_time;
-    let body = Body::from(
-        serde_json::to_string(&gen_time)
-            .expect("Genesis should time always have a valid JSON serialization."),
-    );
-    Ok(success_response(body))
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
+    ResponseBuilder::new(&req)?.body(&beacon_chain.head().beacon_state.genesis_time)
 }

beacon_node/rest_api/src/response_builder.rs

@@ -0,0 +1,99 @@
+use super::{ApiError, ApiResult};
+use http::header;
+use hyper::{Body, Request, Response, StatusCode};
+use serde::Serialize;
+use ssz::Encode;
+
+pub enum Encoding {
+    JSON,
+    SSZ,
+    YAML,
+    TEXT,
+}
+
+pub struct ResponseBuilder {
+    encoding: Encoding,
+}
+
+impl ResponseBuilder {
+    pub fn new(req: &Request<Body>) -> Result<Self, ApiError> {
+        let content_header: String = req
+            .headers()
+            .get(header::CONTENT_TYPE)
+            .map_or(Ok(""), |h| h.to_str())
+            .map_err(|e| {
+                ApiError::BadRequest(format!(
+                    "The content-type header contains invalid characters: {:?}",
+                    e
+                ))
+            })
+            .map(|h| String::from(h))?;
+
+        // JSON is our default encoding, unless something else is requested.
+        let encoding = match content_header {
+            ref h if h.starts_with("application/ssz") => Encoding::SSZ,
+            ref h if h.starts_with("application/yaml") => Encoding::YAML,
+            ref h if h.starts_with("text/") => Encoding::TEXT,
+            _ => Encoding::JSON,
+        };
+        Ok(Self { encoding })
+    }
+
+    pub fn body<T: Serialize + Encode>(self, item: &T) -> ApiResult {
+        match self.encoding {
+            Encoding::SSZ => Response::builder()
+                .status(StatusCode::OK)
+                .header("content-type", "application/ssz")
+                .body(Body::from(item.as_ssz_bytes()))
+                .map_err(|e| ApiError::ServerError(format!("Failed to build response: {:?}", e))),
+            _ => self.body_no_ssz(item),
+        }
+    }
+
+    pub fn body_no_ssz<T: Serialize>(self, item: &T) -> ApiResult {
+        let (body, content_type) = match self.encoding {
+            Encoding::JSON => (
+                Body::from(serde_json::to_string(&item).map_err(|e| {
+                    ApiError::ServerError(format!(
+                        "Unable to serialize response body as JSON: {:?}",
+                        e
+                    ))
+                })?),
+                "application/json",
+            ),
+            Encoding::SSZ => {
+                return Err(ApiError::UnsupportedType(
+                    "Response cannot be encoded as SSZ.".into(),
+                ));
+            }
+            Encoding::YAML => (
+                Body::from(serde_yaml::to_string(&item).map_err(|e| {
+                    ApiError::ServerError(format!(
+                        "Unable to serialize response body as YAML: {:?}",
+                        e
+                    ))
+                })?),
+                "application/yaml",
+            ),
+            Encoding::TEXT => {
+                return Err(ApiError::UnsupportedType(
+                    "Response cannot be encoded as plain text.".into(),
+                ));
+            }
+        };
+
+        Response::builder()
+            .status(StatusCode::OK)
+            .header("content-type", content_type)
+            .body(Body::from(body))
+            .map_err(|e| ApiError::ServerError(format!("Failed to build response: {:?}", e)))
+    }
+
+    pub fn body_text(self, text: String) -> ApiResult {
+        Response::builder()
+            .status(StatusCode::OK)
+            .header("content-type", "text/plain; charset=utf-8")
+            .body(Body::from(text))
+            .map_err(|e| ApiError::ServerError(format!("Failed to build response: {:?}", e)))
+    }
+}

beacon_node/rest_api/src/spec.rs

@@ -1,27 +1,30 @@
-use super::{success_response, ApiResult};
+use super::ApiResult;
+use crate::helpers::get_beacon_chain_from_request;
+use crate::response_builder::ResponseBuilder;
 use crate::ApiError;
-use beacon_chain::{BeaconChain, BeaconChainTypes};
+use beacon_chain::BeaconChainTypes;
+use eth2_config::Eth2Config;
 use hyper::{Body, Request};
 use std::sync::Arc;
 use types::EthSpec;
 
 /// HTTP handler to return the full spec object.
 pub fn get_spec<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
-    let beacon_chain = req
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
+    ResponseBuilder::new(&req)?.body_no_ssz(&beacon_chain.spec)
+}
+
+/// HTTP handler to return the full Eth2Config object.
+pub fn get_eth2_config<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
+    let eth2_config = req
         .extensions()
-        .get::<Arc<BeaconChain<T>>>()
-        .ok_or_else(|| ApiError::ServerError("Beacon chain extension missing".to_string()))?;
+        .get::<Arc<Eth2Config>>()
+        .ok_or_else(|| ApiError::ServerError("Eth2Config extension missing".to_string()))?;
 
-    let json: String = serde_json::to_string(&beacon_chain.spec)
-        .map_err(|e| ApiError::ServerError(format!("Unable to serialize spec: {:?}", e)))?;
-
-    Ok(success_response(Body::from(json)))
+    ResponseBuilder::new(&req)?.body_no_ssz(eth2_config.as_ref())
 }
 
 /// HTTP handler to return the full spec object.
-pub fn get_slots_per_epoch<T: BeaconChainTypes + 'static>(_req: Request<Body>) -> ApiResult {
-    let json: String = serde_json::to_string(&T::EthSpec::slots_per_epoch())
-        .map_err(|e| ApiError::ServerError(format!("Unable to serialize epoch: {:?}", e)))?;
-
-    Ok(success_response(Body::from(json)))
+pub fn get_slots_per_epoch<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
+    ResponseBuilder::new(&req)?.body(&T::EthSpec::slots_per_epoch())
 }

beacon_node/rest_api/src/url_query.rs

@@ -12,7 +12,7 @@ impl<'a> UrlQuery<'a> {
     /// Returns `Err` if `req` does not contain any query parameters.
     pub fn from_request<T>(req: &'a Request<T>) -> Result<Self, ApiError> {
         let query_str = req.uri().query().ok_or_else(|| {
-            ApiError::InvalidQueryParams(
+            ApiError::BadRequest(
                 "URL query must be valid and contain at least one key.".to_string(),
             )
         })?;
@@ -28,7 +28,7 @@ impl<'a> UrlQuery<'a> {
             .find(|(key, _value)| keys.contains(&&**key))
             .map(|(key, value)| (key.into_owned(), value.into_owned()))
             .ok_or_else(|| {
-                ApiError::InvalidQueryParams(format!(
+                ApiError::BadRequest(format!(
                     "URL query must contain at least one of the following keys: {:?}",
                     keys
                 ))
@@ -48,13 +48,13 @@ impl<'a> UrlQuery<'a> {
             if first_key == key {
                 Ok(first_value.to_string())
             } else {
-                Err(ApiError::InvalidQueryParams(format!(
+                Err(ApiError::BadRequest(format!(
                     "Only the {} query parameter is supported",
                     key
                 )))
             }
         } else {
-            Err(ApiError::InvalidQueryParams(format!(
+            Err(ApiError::BadRequest(format!(
                 "Only one query parameter is allowed, {} supplied",
                 queries.len()
             )))
@@ -64,7 +64,7 @@ impl<'a> UrlQuery<'a> {
     /// Returns a vector of all values present where `key` is in `keys
     ///
     /// If no match is found, an `InvalidQueryParams` error is returned.
-    pub fn all_of(mut self, key: &str) -> Result<Vec<String>, ApiError> {
+    pub fn all_of(self, key: &str) -> Result<Vec<String>, ApiError> {
         let queries: Vec<_> = self
             .0
             .filter_map(|(k, v)| {

beacon_node/rest_api/src/validator.rs

@@ -1,13 +1,23 @@
-use super::{success_response, ApiResult};
-use crate::{helpers::*, ApiError, UrlQuery};
-use beacon_chain::{BeaconChain, BeaconChainTypes};
-use bls::PublicKey;
+use crate::helpers::{
+    check_content_type_for_json, get_beacon_chain_from_request, get_logger_from_request,
+    parse_pubkey, publish_attestation_to_network, publish_beacon_block_to_network,
+};
+use crate::response_builder::ResponseBuilder;
+use crate::{ApiError, ApiResult, BoxFut, UrlQuery};
+use beacon_chain::{AttestationProcessingOutcome, BeaconChainTypes, BlockProcessingOutcome};
+use bls::{AggregateSignature, PublicKey, Signature};
+use futures::future::Future;
+use futures::stream::Stream;
 use hyper::{Body, Request};
+use network::NetworkMessage;
+use parking_lot::RwLock;
 use serde::{Deserialize, Serialize};
+use slog::{info, trace, warn};
 use std::sync::Arc;
-use store::Store;
+use tokio;
+use tokio::sync::mpsc;
 use types::beacon_state::EthSpec;
-use types::{BeaconBlock, BeaconState, Epoch, RelativeEpoch, Shard, Slot};
+use types::{Attestation, BeaconBlock, BitList, Epoch, RelativeEpoch, Shard, Slot};
 
 #[derive(Debug, Serialize, Deserialize)]
 pub struct ValidatorDuty {
@@ -34,49 +44,47 @@ impl ValidatorDuty {
 
 /// HTTP Handler to retrieve a the duties for a set of validators during a particular epoch
 pub fn get_validator_duties<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
-    // Get beacon state
-    let beacon_chain = req
-        .extensions()
-        .get::<Arc<BeaconChain<T>>>()
-        .ok_or_else(|| ApiError::ServerError("Beacon chain extension missing".to_string()))?;
-    let _ = beacon_chain
-        .ensure_state_caches_are_built()
-        .map_err(|e| ApiError::ServerError(format!("Unable to build state caches: {:?}", e)))?;
-    let head_state = beacon_chain
-        .speculative_state()
-        .expect("This is legacy code and should be removed.");
+    let log = get_logger_from_request(&req);
+    slog::trace!(log, "Validator duties requested of API: {:?}", &req);
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
+    let mut head_state = beacon_chain.head().beacon_state;
 
+    slog::trace!(log, "Got head state from request.");
     // Parse and check query parameters
     let query = UrlQuery::from_request(&req)?;
-
     let current_epoch = head_state.current_epoch();
     let epoch = match query.first_of(&["epoch"]) {
-        Ok((_, v)) => Epoch::new(v.parse::<u64>().map_err(|e| {
-            ApiError::InvalidQueryParams(format!("Invalid epoch parameter, must be a u64. {:?}", e))
-        })?),
+        Ok((_, v)) => {
+            slog::trace!(log, "Requested epoch {:?}", v);
+            Epoch::new(v.parse::<u64>().map_err(|e| {
+                slog::info!(log, "Invalid epoch {:?}", e);
+                ApiError::BadRequest(format!("Invalid epoch parameter, must be a u64. {:?}", e))
+            })?)
+        }
         Err(_) => {
             // epoch not supplied, use the current epoch
+            slog::info!(log, "Using default epoch {:?}", current_epoch);
             current_epoch
         }
     };
     let relative_epoch = RelativeEpoch::from_epoch(current_epoch, epoch).map_err(|e| {
-        ApiError::InvalidQueryParams(format!(
+        slog::info!(log, "Requested epoch out of range.");
+        ApiError::BadRequest(format!(
             "Cannot get RelativeEpoch, epoch out of range: {:?}",
             e
         ))
     })?;
-    //TODO: Handle an array of validators, currently only takes one
-    let mut validators: Vec<PublicKey> = match query.all_of("validator_pubkeys") {
-        Ok(v) => v
-            .iter()
-            .map(|pk| parse_pubkey(pk))
-            .collect::<Result<Vec<_>, _>>()?,
-        Err(e) => {
-            return Err(e);
-        }
-    };
+    let validators: Vec<PublicKey> = query
+        .all_of("validator_pubkeys")?
+        .iter()
+        .map(|pk| parse_pubkey(pk))
+        .collect::<Result<Vec<_>, _>>()?;
     let mut duties: Vec<ValidatorDuty> = Vec::new();
 
+    // Build cache for the requested epoch
+    head_state
+        .build_committee_cache(relative_epoch, &beacon_chain.spec)
+        .map_err(|e| ApiError::ServerError(format!("Unable to build committee cache: {:?}", e)))?;
     // Get a list of all validators for this epoch
     let validator_proposers: Vec<usize> = epoch
         .slot_iter(T::EthSpec::slots_per_epoch())
@@ -141,9 +149,263 @@ pub fn get_validator_duties<T: BeaconChainTypes + 'static>(req: Request<Body>) -
 
         duties.append(&mut vec![duty]);
     }
-    let body = Body::from(
-        serde_json::to_string(&duties)
-            .expect("We should always be able to serialize the duties we created."),
-    );
-    Ok(success_response(body))
+    ResponseBuilder::new(&req)?.body_no_ssz(&duties)
+}
+
+/// HTTP Handler to produce a new BeaconBlock from the current state, ready to be signed by a validator.
+pub fn get_new_beacon_block<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
+
+    let query = UrlQuery::from_request(&req)?;
+    let slot = query
+        .first_of(&["slot"])
+        .map(|(_key, value)| value)?
+        .parse::<u64>()
+        .map(Slot::from)
+        .map_err(|e| {
+            ApiError::BadRequest(format!("Invalid slot parameter, must be a u64. {:?}", e))
+        })?;
+    let randao_bytes = query
+        .first_of(&["randao_reveal"])
+        .map(|(_key, value)| value)
+        .map(hex::decode)?
+        .map_err(|e| {
+            ApiError::BadRequest(format!("Invalid hex string for randao_reveal: {:?}", e))
+        })?;
+    let randao_reveal = Signature::from_bytes(randao_bytes.as_slice()).map_err(|e| {
+        ApiError::BadRequest(format!("randao_reveal is not a valid signature: {:?}", e))
+    })?;
+
+    let (new_block, _state) = beacon_chain
+        .produce_block(randao_reveal, slot)
+        .map_err(|e| {
+            ApiError::ServerError(format!(
+                "Beacon node is not able to produce a block: {:?}",
+                e
+            ))
+        })?;
+
+    ResponseBuilder::new(&req)?.body(&new_block)
+}
+
+/// HTTP Handler to publish a BeaconBlock, which has been signed by a validator.
+pub fn publish_beacon_block<T: BeaconChainTypes + 'static>(req: Request<Body>) -> BoxFut {
+    let _ = try_future!(check_content_type_for_json(&req));
+    let log = get_logger_from_request(&req);
+    let beacon_chain = try_future!(get_beacon_chain_from_request::<T>(&req));
+    // Get the network sending channel from the request, for later transmission
+    let network_chan = req
+        .extensions()
+        .get::<Arc<RwLock<mpsc::UnboundedSender<NetworkMessage>>>>()
+        .expect("Should always get the network channel from the request, since we put it in there.")
+        .clone();
+
+    let response_builder = ResponseBuilder::new(&req);
+
+    let body = req.into_body();
+    trace!(
+        log,
+        "Got the request body, now going to parse it into a block."
+    );
+    Box::new(body
+        .concat2()
+        .map_err(|e| ApiError::ServerError(format!("Unable to get request body: {:?}",e)))
+        .map(|chunk| chunk.iter().cloned().collect::<Vec<u8>>())
+        .and_then(|chunks| {
+            serde_json::from_slice(&chunks.as_slice()).map_err(|e| {
+                ApiError::BadRequest(format!(
+                    "Unable to deserialize JSON into a BeaconBlock: {:?}",
+                    e
+                ))
+            })
+        })
+        .and_then(move |block: BeaconBlock<T::EthSpec>| {
+            let slot = block.slot;
+            match beacon_chain.process_block(block.clone()) {
+                Ok(BlockProcessingOutcome::Processed { block_root }) => {
+                    // Block was processed, publish via gossipsub
+                    info!(log, "Processed valid block from API, transmitting to network."; "block_slot" => slot, "block_root" => format!("{}", block_root));
+                    publish_beacon_block_to_network::<T>(network_chan, block)
+                }
+                Ok(outcome) => {
+                    warn!(log, "BeaconBlock could not be processed, but is being sent to the network anyway."; "outcome" => format!("{:?}", outcome));
+                    publish_beacon_block_to_network::<T>(network_chan, block)?;
+                    Err(ApiError::ProcessingError(format!(
+                        "The BeaconBlock could not be processed, but has still been published: {:?}",
+                        outcome
+                    )))
+                }
+                Err(e) => {
+                    Err(ApiError::ServerError(format!(
+                        "Error while processing block: {:?}",
+                        e
+                    )))
+                }
+            }
+        }).and_then(|_| {
+            response_builder?.body_no_ssz(&())
+        }))
+}
+
+/// HTTP Handler to produce a new Attestation from the current state, ready to be signed by a validator.
+pub fn get_new_attestation<T: BeaconChainTypes + 'static>(req: Request<Body>) -> ApiResult {
+    let beacon_chain = get_beacon_chain_from_request::<T>(&req)?;
+    let mut head_state = beacon_chain.head().beacon_state;
+
+    let query = UrlQuery::from_request(&req)?;
+    let val_pk_str = query
+        .first_of(&["validator_pubkey"])
+        .map(|(_key, value)| value)?;
+    let val_pk = parse_pubkey(val_pk_str.as_str())?;
+
+    head_state
+        .update_pubkey_cache()
+        .map_err(|e| ApiError::ServerError(format!("Unable to build pubkey cache: {:?}", e)))?;
+    // Get the validator index from the supplied public key
+    // If it does not exist in the index, we cannot continue.
+    let val_index = head_state
+        .get_validator_index(&val_pk)
+        .map_err(|e| {
+            ApiError::ServerError(format!("Unable to read validator index cache. {:?}", e))
+        })?
+        .ok_or(ApiError::BadRequest(
+            "The provided validator public key does not correspond to a validator index.".into(),
+        ))?;
+
+    // Build cache for the requested epoch
+    head_state
+        .build_committee_cache(RelativeEpoch::Current, &beacon_chain.spec)
+        .map_err(|e| ApiError::ServerError(format!("Unable to build committee cache: {:?}", e)))?;
+    // Get the duties of the validator, to make sure they match up.
+    // If they don't have duties this epoch, then return an error
+    let val_duty = head_state
+        .get_attestation_duties(val_index, RelativeEpoch::Current)
+        .map_err(|e| {
+            ApiError::ServerError(format!(
+                "unable to read cache for attestation duties: {:?}",
+                e
+            ))
+        })?
+        .ok_or(ApiError::BadRequest("No validator duties could be found for the requested validator. Cannot provide valid attestation.".into()))?;
+
+    // Check that we are requesting an attestation during the slot where it is relevant.
+    let present_slot = beacon_chain.slot().map_err(|e| ApiError::ServerError(
+        format!("Beacon node is unable to determine present slot, either the state isn't generated or the chain hasn't begun. {:?}", e)
+    ))?;
+    if val_duty.slot != present_slot {
+        return Err(ApiError::BadRequest(format!("Validator is only able to request an attestation during the slot they are allocated. Current slot: {:?}, allocated slot: {:?}", head_state.slot, val_duty.slot)));
+    }
+
+    // Parse the POC bit and insert it into the aggregation bits
+    let poc_bit = query
+        .first_of(&["poc_bit"])
+        .map(|(_key, value)| value)?
+        .parse::<bool>()
+        .map_err(|e| {
+            ApiError::BadRequest(format!("Invalid slot parameter, must be a u64. {:?}", e))
+        })?;
+
+    let mut aggregation_bits = BitList::with_capacity(val_duty.committee_len)
+        .expect("An empty BitList should always be created, or we have bigger problems.");
+    aggregation_bits
+        .set(val_duty.committee_index, poc_bit)
+        .map_err(|e| {
+            ApiError::ServerError(format!(
+                "Unable to set aggregation bits for the attestation: {:?}",
+                e
+            ))
+        })?;
+
+    // Allow a provided slot parameter to check against the expected slot as a sanity check only.
+    // Presently, we don't support attestations at future or past slots.
+    let requested_slot = query
+        .first_of(&["slot"])
+        .map(|(_key, value)| value)?
+        .parse::<u64>()
+        .map(Slot::from)
+        .map_err(|e| {
+            ApiError::BadRequest(format!("Invalid slot parameter, must be a u64. {:?}", e))
+        })?;
+    let current_slot = beacon_chain.head().beacon_state.slot.as_u64();
+    if requested_slot != current_slot {
+        return Err(ApiError::BadRequest(format!("Attestation data can only be requested for the current slot ({:?}), not your requested slot ({:?})", current_slot, requested_slot)));
+    }
+
+    let shard = query
+        .first_of(&["shard"])
+        .map(|(_key, value)| value)?
+        .parse::<u64>()
+        .map_err(|e| ApiError::BadRequest(format!("Shard is not a valid u64 value: {:?}", e)))?;
+
+    let attestation_data = beacon_chain
+        .produce_attestation_data(shard, current_slot.into())
+        .map_err(|e| ApiError::ServerError(format!("Could not produce an attestation: {:?}", e)))?;
+
+    let attestation: Attestation<T::EthSpec> = Attestation {
+        aggregation_bits,
+        data: attestation_data,
+        custody_bits: BitList::with_capacity(val_duty.committee_len)
+            .expect("Should be able to create an empty BitList for the custody bits."),
+        signature: AggregateSignature::new(),
+    };
+
+    ResponseBuilder::new(&req)?.body(&attestation)
+}
+
+/// HTTP Handler to publish an Attestation, which has been signed by a validator.
+pub fn publish_attestation<T: BeaconChainTypes + 'static>(req: Request<Body>) -> BoxFut {
+    let _ = try_future!(check_content_type_for_json(&req));
+    let log = get_logger_from_request(&req);
+    let beacon_chain = try_future!(get_beacon_chain_from_request::<T>(&req));
+    // Get the network sending channel from the request, for later transmission
+    let network_chan = req
+        .extensions()
+        .get::<Arc<RwLock<mpsc::UnboundedSender<NetworkMessage>>>>()
+        .expect("Should always get the network channel from the request, since we put it in there.")
+        .clone();
+
+    let response_builder = ResponseBuilder::new(&req);
+
+    let body = req.into_body();
+    trace!(
+        log,
+        "Got the request body, now going to parse it into an attesation."
+    );
+    Box::new(body
+        .concat2()
+        .map_err(|e| ApiError::ServerError(format!("Unable to get request body: {:?}",e)))
+        .map(|chunk| chunk.iter().cloned().collect::<Vec<u8>>())
+        .and_then(|chunks| {
+            serde_json::from_slice(&chunks.as_slice()).map_err(|e| {
+                ApiError::BadRequest(format!(
+                    "Unable to deserialize JSON into a BeaconBlock: {:?}",
+                    e
+                ))
+            })
+        })
+        .and_then(move |attestation: Attestation<T::EthSpec>| {
+            match beacon_chain.process_attestation(attestation.clone()) {
+                Ok(AttestationProcessingOutcome::Processed) => {
+                    // Block was processed, publish via gossipsub
+                    info!(log, "Processed valid attestation from API, transmitting to network.");
+                    publish_attestation_to_network::<T>(network_chan, attestation)
+                }
+                Ok(outcome) => {
+                    warn!(log, "Attestation could not be processed, but is being sent to the network anyway."; "outcome" => format!("{:?}", outcome));
+                    publish_attestation_to_network::<T>(network_chan, attestation)?;
+                    Err(ApiError::ProcessingError(format!(
+                        "The Attestation could not be processed, but has still been published: {:?}",
+                        outcome
+                    )))
+                }
+                Err(e) => {
+                    Err(ApiError::ServerError(format!(
+                        "Error while processing attestation: {:?}",
+                        e
+                    )))
+                }
+            }
+        }).and_then(|_| {
+        response_builder?.body_no_ssz(&())
+    }))
 }

beacon_node/rpc/src/attestation.rs

@@ -14,7 +14,7 @@ use slog::{error, info, trace, warn};
 use ssz::{ssz_encode, Decode, Encode};
 use std::sync::Arc;
 use tokio::sync::mpsc;
-use types::Attestation;
+use types::{Attestation, Slot};
 
 #[derive(Clone)]
 pub struct AttestationServiceInstance<T: BeaconChainTypes> {
@@ -37,49 +37,13 @@ impl<T: BeaconChainTypes> AttestationService for AttestationServiceInstance<T> {
             req.get_slot()
         );
 
-        // verify the slot, drop lock on state afterwards
-        {
-            let slot_requested = req.get_slot();
-            // TODO: this whole module is legacy and not maintained well.
-            let state = &self
-                .chain
-                .speculative_state()
-                .expect("This is legacy code and should be removed");
-
-            // Start by performing some checks
-            // Check that the AttestationData is for the current slot (otherwise it will not be valid)
-            if slot_requested > state.slot.as_u64() {
-                let log_clone = self.log.clone();
-                let f = sink
-                    .fail(RpcStatus::new(
-                        RpcStatusCode::OutOfRange,
-                        Some(
-                            "AttestationData request for a slot that is in the future.".to_string(),
-                        ),
-                    ))
-                    .map_err(move |e| {
-                        error!(log_clone, "Failed to reply with failure {:?}: {:?}", req, e)
-                    });
-                return ctx.spawn(f);
-            }
-            // currently cannot handle past slots. TODO: Handle this case
-            else if slot_requested < state.slot.as_u64() {
-                let log_clone = self.log.clone();
-                let f = sink
-                    .fail(RpcStatus::new(
-                        RpcStatusCode::InvalidArgument,
-                        Some("AttestationData request for a slot that is in the past.".to_string()),
-                    ))
-                    .map_err(move |e| {
-                        error!(log_clone, "Failed to reply with failure {:?}: {:?}", req, e)
-                    });
-                return ctx.spawn(f);
-            }
-        }
-
         // Then get the AttestationData from the beacon chain
         let shard = req.get_shard();
-        let attestation_data = match self.chain.produce_attestation_data(shard) {
+        let slot_requested = req.get_slot();
+        let attestation_data = match self
+            .chain
+            .produce_attestation_data(shard, Slot::from(slot_requested))
+        {
             Ok(v) => v,
             Err(e) => {
                 // Could not produce an attestation

beacon_node/rpc/src/beacon_block.rs

@@ -34,8 +34,7 @@ impl<T: BeaconChainTypes> BeaconBlockService for BeaconBlockServiceInstance<T> {
         trace!(self.log, "Generating a beacon block"; "req" => format!("{:?}", req));
 
         // decode the request
-        // TODO: requested slot currently unused, see: https://github.com/sigp/lighthouse/issues/336
-        let _requested_slot = Slot::from(req.get_slot());
+        let requested_slot = Slot::from(req.get_slot());
         let randao_reveal = match Signature::from_ssz_bytes(req.get_randao_reveal()) {
             Ok(reveal) => reveal,
             Err(_) => {
@@ -51,7 +50,7 @@ impl<T: BeaconChainTypes> BeaconBlockService for BeaconBlockServiceInstance<T> {
             }
         };
 
-        let produced_block = match self.chain.produce_block(randao_reveal) {
+        let produced_block = match self.chain.produce_block(randao_reveal, requested_slot) {
             Ok((block, _state)) => block,
             Err(e) => {
                 // could not produce a block
@@ -67,6 +66,11 @@ impl<T: BeaconChainTypes> BeaconBlockService for BeaconBlockServiceInstance<T> {
             }
         };
 
+        assert_eq!(
+            produced_block.slot, requested_slot,
+            "should produce at the requested slot"
+        );
+
         let mut block = BeaconBlockProto::new();
         block.set_ssz(ssz_encode(&produced_block));
 

beacon_node/rpc/src/config.rs

@@ -16,7 +16,7 @@ pub struct Config {
 impl Default for Config {
     fn default() -> Self {
         Config {
-            enabled: false, // rpc disabled by default
+            enabled: true,
             listen_address: Ipv4Addr::new(127, 0, 0, 1),
             port: 5051,
         }
@@ -25,8 +25,8 @@ impl Default for Config {
 
 impl Config {
     pub fn apply_cli_args(&mut self, args: &ArgMatches) -> Result<(), &'static str> {
-        if args.is_present("rpc") {
-            self.enabled = true;
+        if args.is_present("no-grpc") {
+            self.enabled = false;
         }
 
         if let Some(rpc_address) = args.value_of("rpc-address") {

beacon_node/rpc/src/lib.rs

@@ -80,7 +80,12 @@ pub fn start_server<T: BeaconChainTypes + Clone + 'static>(
     let spawn_rpc = {
         server.start();
         for &(ref host, port) in server.bind_addrs() {
-            info!(log, "gRPC listening on {}:{}", host, port);
+            info!(
+                log,
+                "gRPC API started";
+                "port" => port,
+                "host" => host,
+            );
         }
         rpc_exit.and_then(move |_| {
             info!(log, "RPC Server shutting down");

beacon_node/rpc/src/validator.rs

@@ -25,39 +25,41 @@ impl<T: BeaconChainTypes> ValidatorService for ValidatorServiceInstance<T> {
         req: GetDutiesRequest,
         sink: UnarySink<GetDutiesResponse>,
     ) {
-        let validators = req.get_validators();
         trace!(self.log, "RPC request"; "endpoint" => "GetValidatorDuties", "epoch" => req.get_epoch());
+        let validators = req.get_validators();
 
-        let spec = &self.chain.spec;
-        // TODO: this whole module is legacy and not maintained well.
-        let state = &self
-            .chain
-            .speculative_state()
-            .expect("This is legacy code and should be removed");
         let epoch = Epoch::from(req.get_epoch());
+        let slot = epoch.start_slot(T::EthSpec::slots_per_epoch());
+
+        let mut state = if let Ok(state) = self.chain.state_at_slot(slot) {
+            state.clone()
+        } else {
+            let log_clone = self.log.clone();
+            let f = sink
+                .fail(RpcStatus::new(
+                    RpcStatusCode::FailedPrecondition,
+                    Some("No state".to_string()),
+                ))
+                .map_err(move |e| warn!(log_clone, "failed to reply {:?}: {:?}", req, e));
+            return ctx.spawn(f);
+        };
+
+        let _ = state.build_all_caches(&self.chain.spec);
+
+        assert_eq!(
+            state.current_epoch(),
+            epoch,
+            "Retrieved state should be from the same epoch"
+        );
+
         let mut resp = GetDutiesResponse::new();
         let resp_validators = resp.mut_active_validators();
 
-        let relative_epoch =
-            match RelativeEpoch::from_epoch(state.slot.epoch(T::EthSpec::slots_per_epoch()), epoch)
-            {
-                Ok(v) => v,
-                Err(e) => {
-                    // incorrect epoch
-                    let log_clone = self.log.clone();
-                    let f = sink
-                        .fail(RpcStatus::new(
-                            RpcStatusCode::FailedPrecondition,
-                            Some(format!("Invalid epoch: {:?}", e)),
-                        ))
-                        .map_err(move |e| warn!(log_clone, "failed to reply {:?}: {:?}", req, e));
-                    return ctx.spawn(f);
-                }
-            };
-
         let validator_proposers: Result<Vec<usize>, _> = epoch
             .slot_iter(T::EthSpec::slots_per_epoch())
-            .map(|slot| state.get_beacon_proposer_index(slot, relative_epoch, &spec))
+            .map(|slot| {
+                state.get_beacon_proposer_index(slot, RelativeEpoch::Current, &self.chain.spec)
+            })
             .collect();
         let validator_proposers = match validator_proposers {
             Ok(v) => v,

beacon_node/src/config.rs

@@ -0,0 +1,575 @@
+use clap::ArgMatches;
+use client::{BeaconChainStartMethod, ClientConfig, Eth1BackendMethod, Eth2Config};
+use eth2_config::{read_from_file, write_to_file};
+use lighthouse_bootstrap::Bootstrapper;
+use rand::{distributions::Alphanumeric, Rng};
+use slog::{crit, info, warn, Logger};
+use std::fs;
+use std::net::Ipv4Addr;
+use std::path::{Path, PathBuf};
+
+pub const DEFAULT_DATA_DIR: &str = ".lighthouse";
+pub const CLIENT_CONFIG_FILENAME: &str = "beacon-node.toml";
+pub const ETH2_CONFIG_FILENAME: &str = "eth2-spec.toml";
+
+type Result<T> = std::result::Result<T, String>;
+type Config = (ClientConfig, Eth2Config, Logger);
+
+/// Gets the fully-initialized global client and eth2 configuration objects.
+///
+/// The top-level `clap` arguments should be provied as `cli_args`.
+///
+/// The output of this function depends primarily upon the given `cli_args`, however it's behaviour
+/// may be influenced by other external services like the contents of the file system or the
+/// response of some remote server.
+pub fn get_configs(cli_args: &ArgMatches, core_log: Logger) -> Result<Config> {
+    let log = core_log.clone();
+
+    let mut builder = ConfigBuilder::new(cli_args, core_log)?;
+
+    if let Some(server) = cli_args.value_of("eth1-server") {
+        builder.set_eth1_backend_method(Eth1BackendMethod::Web3 {
+            server: server.into(),
+        })
+    } else {
+        builder.set_eth1_backend_method(Eth1BackendMethod::Interop)
+    }
+
+    match cli_args.subcommand() {
+        ("testnet", Some(sub_cmd_args)) => {
+            process_testnet_subcommand(&mut builder, sub_cmd_args, &log)?
+        }
+        // No sub-command assumes a resume operation.
+        _ => {
+            info!(
+                log,
+                "Resuming from existing datadir";
+                "path" => format!("{:?}", builder.client_config.data_dir)
+            );
+
+            // If no primary subcommand was given, start the beacon chain from an existing
+            // database.
+            builder.set_beacon_chain_start_method(BeaconChainStartMethod::Resume);
+
+            // Whilst there is no large testnet or mainnet force the user to specify how they want
+            // to start a new chain (e.g., from a genesis YAML file, another node, etc).
+            if !builder.client_config.data_dir.exists() {
+                return Err(
+                    "No datadir found. To start a new beacon chain, see `testnet --help`. \
+                     Use `--datadir` to specify a different directory"
+                        .into(),
+                );
+            }
+
+            // If the `testnet` command was not provided, attempt to load an existing datadir and
+            // continue with an existing chain.
+            builder.load_from_datadir()?;
+        }
+    };
+
+    builder.build(cli_args)
+}
+
+/// Process the `testnet` CLI subcommand arguments, updating the `builder`.
+fn process_testnet_subcommand(
+    builder: &mut ConfigBuilder,
+    cli_args: &ArgMatches,
+    log: &Logger,
+) -> Result<()> {
+    if cli_args.is_present("random-datadir") {
+        builder.set_random_datadir()?;
+    }
+
+    if cli_args.is_present("force") {
+        builder.clean_datadir()?;
+    }
+
+    let is_bootstrap = cli_args.subcommand_name() == Some("bootstrap");
+
+    if let Some(path_string) = cli_args.value_of("eth2-config") {
+        if is_bootstrap {
+            return Err("Cannot supply --eth2-config when using bootstrap".to_string());
+        }
+
+        let path = path_string
+            .parse::<PathBuf>()
+            .map_err(|e| format!("Unable to parse eth2-config path: {:?}", e))?;
+        builder.load_eth2_config(path)?;
+    } else {
+        builder.update_spec_from_subcommand(&cli_args)?;
+    }
+
+    if let Some(slot_time) = cli_args.value_of("slot-time") {
+        if is_bootstrap {
+            return Err("Cannot supply --slot-time flag whilst using bootstrap.".into());
+        }
+
+        let slot_time = slot_time
+            .parse::<u64>()
+            .map_err(|e| format!("Unable to parse slot-time: {:?}", e))?;
+
+        builder.set_slot_time(slot_time);
+    }
+
+    if let Some(path_string) = cli_args.value_of("client-config") {
+        let path = path_string
+            .parse::<PathBuf>()
+            .map_err(|e| format!("Unable to parse client config path: {:?}", e))?;
+        builder.load_client_config(path)?;
+    }
+
+    info!(
+        log,
+        "Creating new datadir";
+        "path" => format!("{:?}", builder.client_config.data_dir)
+    );
+
+    // When using the testnet command we listen on all addresses.
+    builder.set_listen_addresses("0.0.0.0".into())?;
+    warn!(log, "All services listening on 0.0.0.0");
+
+    // Start matching on the second subcommand (e.g., `testnet bootstrap ...`).
+    match cli_args.subcommand() {
+        ("bootstrap", Some(cli_args)) => {
+            let server = cli_args
+                .value_of("server")
+                .ok_or_else(|| "No bootstrap server specified")?;
+            let port: Option<u16> = cli_args
+                .value_of("libp2p-port")
+                .and_then(|s| s.parse::<u16>().ok());
+
+            builder.import_bootstrap_libp2p_address(server, port)?;
+            builder.import_bootstrap_enr_address(server)?;
+            builder.import_bootstrap_eth2_config(server)?;
+
+            builder.set_beacon_chain_start_method(BeaconChainStartMethod::HttpBootstrap {
+                server: server.to_string(),
+                port,
+            })
+        }
+        ("recent", Some(cli_args)) => {
+            let validator_count = cli_args
+                .value_of("validator_count")
+                .ok_or_else(|| "No validator_count specified")?
+                .parse::<usize>()
+                .map_err(|e| format!("Unable to parse validator_count: {:?}", e))?;
+
+            let minutes = cli_args
+                .value_of("minutes")
+                .ok_or_else(|| "No recent genesis minutes supplied")?
+                .parse::<u64>()
+                .map_err(|e| format!("Unable to parse minutes: {:?}", e))?;
+
+            builder.set_beacon_chain_start_method(BeaconChainStartMethod::RecentGenesis {
+                validator_count,
+                minutes,
+            })
+        }
+        ("quick", Some(cli_args)) => {
+            let validator_count = cli_args
+                .value_of("validator_count")
+                .ok_or_else(|| "No validator_count specified")?
+                .parse::<usize>()
+                .map_err(|e| format!("Unable to parse validator_count: {:?}", e))?;
+
+            let genesis_time = cli_args
+                .value_of("genesis_time")
+                .ok_or_else(|| "No genesis time supplied")?
+                .parse::<u64>()
+                .map_err(|e| format!("Unable to parse genesis time: {:?}", e))?;
+
+            builder.set_beacon_chain_start_method(BeaconChainStartMethod::Generated {
+                validator_count,
+                genesis_time,
+            })
+        }
+        ("file", Some(cli_args)) => {
+            let file = cli_args
+                .value_of("file")
+                .ok_or_else(|| "No filename specified")?
+                .parse::<PathBuf>()
+                .map_err(|e| format!("Unable to parse filename: {:?}", e))?;
+
+            let format = cli_args
+                .value_of("format")
+                .ok_or_else(|| "No file format specified")?;
+
+            let start_method = match format {
+                "yaml" => BeaconChainStartMethod::Yaml { file },
+                "ssz" => BeaconChainStartMethod::Ssz { file },
+                "json" => BeaconChainStartMethod::Json { file },
+                other => return Err(format!("Unknown genesis file format: {}", other)),
+            };
+
+            builder.set_beacon_chain_start_method(start_method)
+        }
+        (cmd, Some(_)) => {
+            return Err(format!(
+                "Invalid valid method specified: {}. See 'testnet --help'.",
+                cmd
+            ))
+        }
+        _ => return Err("No testnet method specified. See 'testnet --help'.".into()),
+    };
+
+    builder.write_configs_to_new_datadir()?;
+
+    Ok(())
+}
+
+/// Allows for building a set of configurations based upon `clap` arguments.
+struct ConfigBuilder {
+    log: Logger,
+    eth2_config: Eth2Config,
+    client_config: ClientConfig,
+}
+
+impl ConfigBuilder {
+    /// Create a new builder with default settings.
+    pub fn new(cli_args: &ArgMatches, log: Logger) -> Result<Self> {
+        // Read the `--datadir` flag.
+        //
+        // If it's not present, try and find the home directory (`~`) and push the default data
+        // directory onto it.
+        let data_dir: PathBuf = cli_args
+            .value_of("datadir")
+            .map(|string| PathBuf::from(string))
+            .or_else(|| {
+                dirs::home_dir().map(|mut home| {
+                    home.push(DEFAULT_DATA_DIR);
+                    home
+                })
+            })
+            .ok_or_else(|| "Unable to find a home directory for the datadir".to_string())?;
+
+        let mut client_config = ClientConfig::default();
+        client_config.data_dir = data_dir;
+
+        Ok(Self {
+            log,
+            eth2_config: Eth2Config::minimal(),
+            client_config,
+        })
+    }
+
+    /// Clears any configuration files that would interfere with writing new configs.
+    ///
+    /// Moves the following files in `data_dir` into a backup directory:
+    ///
+    /// - Client config
+    /// - Eth2 config
+    /// - The entire database directory
+    pub fn clean_datadir(&mut self) -> Result<()> {
+        let backup_dir = {
+            let mut s = String::from("backup_");
+            s.push_str(&random_string(6));
+            self.client_config.data_dir.join(s)
+        };
+
+        fs::create_dir_all(&backup_dir)
+            .map_err(|e| format!("Unable to create config backup dir: {:?}", e))?;
+
+        let move_to_backup_dir = |path: &Path| -> Result<()> {
+            let file_name = path
+                .file_name()
+                .ok_or_else(|| "Invalid path found during datadir clean (no filename).")?;
+
+            let mut new = path.to_path_buf();
+            new.pop();
+            new.push(backup_dir.clone());
+            new.push(file_name);
+
+            let _ = fs::rename(path, new);
+
+            Ok(())
+        };
+
+        move_to_backup_dir(&self.client_config.data_dir.join(CLIENT_CONFIG_FILENAME))?;
+        move_to_backup_dir(&self.client_config.data_dir.join(ETH2_CONFIG_FILENAME))?;
+
+        if let Some(db_path) = self.client_config.db_path() {
+            move_to_backup_dir(&db_path)?;
+        }
+
+        Ok(())
+    }
+
+    /// Sets the method for starting the beacon chain.
+    pub fn set_beacon_chain_start_method(&mut self, method: BeaconChainStartMethod) {
+        self.client_config.beacon_chain_start_method = method;
+    }
+
+    /// Sets the method for starting the beacon chain.
+    pub fn set_eth1_backend_method(&mut self, method: Eth1BackendMethod) {
+        self.client_config.eth1_backend_method = method;
+    }
+
+    /// Import the libp2p address for `server` into the list of libp2p nodes to connect with.
+    ///
+    /// If `port` is `Some`, it is used as the port for the `Multiaddr`. If `port` is `None`,
+    /// attempts to connect to the `server` via HTTP and retrieve it's libp2p listen port.
+    pub fn import_bootstrap_libp2p_address(
+        &mut self,
+        server: &str,
+        port: Option<u16>,
+    ) -> Result<()> {
+        let bootstrapper = Bootstrapper::connect(server.to_string(), &self.log)?;
+
+        if let Some(server_multiaddr) = bootstrapper.best_effort_multiaddr(port) {
+            info!(
+                self.log,
+                "Estimated bootstrapper libp2p address";
+                "multiaddr" => format!("{:?}", server_multiaddr)
+            );
+
+            self.client_config
+                .network
+                .libp2p_nodes
+                .push(server_multiaddr);
+        } else {
+            warn!(
+                self.log,
+                "Unable to estimate a bootstrapper libp2p address, this node may not find any peers."
+            );
+        };
+
+        Ok(())
+    }
+
+    /// Import the enr address for `server` into the list of initial enrs (boot nodes).
+    pub fn import_bootstrap_enr_address(&mut self, server: &str) -> Result<()> {
+        let bootstrapper = Bootstrapper::connect(server.to_string(), &self.log)?;
+
+        if let Ok(enr) = bootstrapper.enr() {
+            info!(
+                self.log,
+                "Loaded bootstrapper libp2p address";
+                "enr" => format!("{:?}", enr)
+            );
+
+            self.client_config.network.boot_nodes.push(enr);
+        } else {
+            warn!(
+                self.log,
+                "Unable to estimate a bootstrapper enr address, this node may not find any peers."
+            );
+        };
+
+        Ok(())
+    }
+
+    /// Set the config data_dir to be an random directory.
+    ///
+    /// Useful for easily spinning up ephemeral testnets.
+    pub fn set_random_datadir(&mut self) -> Result<()> {
+        self.client_config
+            .data_dir
+            .push(format!("random_{}", random_string(6)));
+        self.client_config.network.network_dir = self.client_config.data_dir.join("network");
+
+        Ok(())
+    }
+
+    /// Imports an `Eth2Config` from `server`, returning an error if this fails.
+    pub fn import_bootstrap_eth2_config(&mut self, server: &str) -> Result<()> {
+        let bootstrapper = Bootstrapper::connect(server.to_string(), &self.log)?;
+
+        self.update_eth2_config(bootstrapper.eth2_config()?);
+
+        Ok(())
+    }
+
+    fn update_eth2_config(&mut self, eth2_config: Eth2Config) {
+        self.eth2_config = eth2_config;
+    }
+
+    fn set_slot_time(&mut self, milliseconds_per_slot: u64) {
+        self.eth2_config.spec.milliseconds_per_slot = milliseconds_per_slot;
+    }
+
+    /// Reads the subcommand and tries to update `self.eth2_config` based up on the `--spec` flag.
+    ///
+    /// Returns an error if the `--spec` flag is not present in the given `cli_args`.
+    pub fn update_spec_from_subcommand(&mut self, cli_args: &ArgMatches) -> Result<()> {
+        // Re-initialise the `Eth2Config`.
+        //
+        // If a CLI parameter is set, overwrite any config file present.
+        // If a parameter is not set, use either the config file present or default to minimal.
+        let eth2_config = match cli_args.value_of("spec") {
+            Some("mainnet") => Eth2Config::mainnet(),
+            Some("minimal") => Eth2Config::minimal(),
+            Some("interop") => Eth2Config::interop(),
+            _ => return Err("Unable to determine specification type.".into()),
+        };
+
+        self.client_config.spec_constants = cli_args
+            .value_of("spec")
+            .expect("Guarded by prior match statement")
+            .to_string();
+        self.eth2_config = eth2_config;
+
+        Ok(())
+    }
+
+    /// Writes the configs in `self` to `self.data_dir`.
+    ///
+    /// Returns an error if `self.data_dir` already exists.
+    pub fn write_configs_to_new_datadir(&mut self) -> Result<()> {
+        let db_exists = self
+            .client_config
+            .db_path()
+            .map(|d| d.exists())
+            .unwrap_or_else(|| false);
+
+        // Do not permit creating a new config when the datadir exists.
+        if db_exists {
+            return Err("Database already exists. See `-f` or `-r` in `testnet --help`".into());
+        }
+
+        // Create `datadir` and any non-existing parent directories.
+        fs::create_dir_all(&self.client_config.data_dir).map_err(|e| {
+            crit!(self.log, "Failed to initialize data dir"; "error" => format!("{}", e));
+            format!("{}", e)
+        })?;
+
+        let client_config_file = self.client_config.data_dir.join(CLIENT_CONFIG_FILENAME);
+        if client_config_file.exists() {
+            return Err(format!(
+                "Datadir is not clean, {} exists. See `-f` in `testnet --help`.",
+                CLIENT_CONFIG_FILENAME
+            ));
+        } else {
+            // Write the onfig to a TOML file in the datadir.
+            write_to_file(
+                self.client_config.data_dir.join(CLIENT_CONFIG_FILENAME),
+                &self.client_config,
+            )
+            .map_err(|e| format!("Unable to write {} file: {:?}", CLIENT_CONFIG_FILENAME, e))?;
+        }
+
+        let eth2_config_file = self.client_config.data_dir.join(ETH2_CONFIG_FILENAME);
+        if eth2_config_file.exists() {
+            return Err(format!(
+                "Datadir is not clean, {} exists. See `-f` in `testnet --help`.",
+                ETH2_CONFIG_FILENAME
+            ));
+        } else {
+            // Write the config to a TOML file in the datadir.
+            write_to_file(
+                self.client_config.data_dir.join(ETH2_CONFIG_FILENAME),
+                &self.eth2_config,
+            )
+            .map_err(|e| format!("Unable to write {} file: {:?}", ETH2_CONFIG_FILENAME, e))?;
+        }
+
+        Ok(())
+    }
+
+    /// Attempts to load the client and eth2 configs from `self.data_dir`.
+    ///
+    /// Returns an error if any files are not found or are invalid.
+    pub fn load_from_datadir(&mut self) -> Result<()> {
+        // Check to ensure the datadir exists.
+        //
+        // For now we return an error. In the future we may decide to boot a default (e.g.,
+        // public testnet or mainnet).
+        if !self.client_config.data_dir.exists() {
+            return Err(
+                "No datadir found. Either create a new testnet or specify a different `--datadir`."
+                    .into(),
+            );
+        }
+
+        // If there is a path to a databse in the config, ensure it exists.
+        if !self
+            .client_config
+            .db_path()
+            .map(|path| path.exists())
+            .unwrap_or_else(|| true)
+        {
+            return Err(
+                "No database found in datadir. Use 'testnet -f' to overwrite the existing \
+                 datadir, or specify a different `--datadir`."
+                    .into(),
+            );
+        }
+
+        self.load_eth2_config(self.client_config.data_dir.join(ETH2_CONFIG_FILENAME))?;
+        self.load_client_config(self.client_config.data_dir.join(CLIENT_CONFIG_FILENAME))?;
+
+        Ok(())
+    }
+
+    /// Attempts to load the client config from `path`.
+    ///
+    /// Returns an error if any files are not found or are invalid.
+    pub fn load_client_config(&mut self, path: PathBuf) -> Result<()> {
+        self.client_config = read_from_file::<ClientConfig>(path.clone())
+            .map_err(|e| format!("Unable to parse {:?} file: {:?}", path, e))?
+            .ok_or_else(|| format!("{:?} file does not exist", path))?;
+
+        Ok(())
+    }
+
+    /// Attempts to load the eth2 config from `path`.
+    ///
+    /// Returns an error if any files are not found or are invalid.
+    pub fn load_eth2_config(&mut self, path: PathBuf) -> Result<()> {
+        self.eth2_config = read_from_file::<Eth2Config>(path.clone())
+            .map_err(|e| format!("Unable to parse {:?} file: {:?}", path, e))?
+            .ok_or_else(|| format!("{:?} file does not exist", path))?;
+
+        Ok(())
+    }
+
+    /// Sets all listening addresses to the given `addr`.
+    pub fn set_listen_addresses(&mut self, addr: String) -> Result<()> {
+        let addr = addr
+            .parse::<Ipv4Addr>()
+            .map_err(|e| format!("Unable to parse default listen address: {:?}", e))?;
+
+        self.client_config.network.listen_address = addr.clone().into();
+        self.client_config.rpc.listen_address = addr.clone();
+        self.client_config.rest_api.listen_address = addr.clone();
+
+        Ok(())
+    }
+
+    /// Consumes self, returning the configs.
+    ///
+    /// The supplied `cli_args` should be the base-level `clap` cli_args (i.e., not a subcommand
+    /// cli_args).
+    pub fn build(mut self, cli_args: &ArgMatches) -> Result<Config> {
+        self.eth2_config.apply_cli_args(cli_args)?;
+        self.client_config.apply_cli_args(cli_args, &mut self.log)?;
+
+        if let Some(bump) = cli_args.value_of("port-bump") {
+            let bump = bump
+                .parse::<u16>()
+                .map_err(|e| format!("Unable to parse port bump: {}", e))?;
+
+            self.client_config.network.libp2p_port += bump;
+            self.client_config.network.discovery_port += bump;
+            self.client_config.rpc.port += bump;
+            self.client_config.rest_api.port += bump;
+            self.client_config.websocket_server.port += bump;
+        }
+
+        if self.eth2_config.spec_constants != self.client_config.spec_constants {
+            crit!(self.log, "Specification constants do not match.";
+                  "client_config" => format!("{}", self.client_config.spec_constants),
+                  "eth2_config" => format!("{}", self.eth2_config.spec_constants)
+            );
+            return Err("Specification constant mismatch".into());
+        }
+
+        Ok((self.client_config, self.eth2_config, self.log))
+    }
+}
+
+fn random_string(len: usize) -> String {
+    rand::thread_rng()
+        .sample_iter(&Alphanumeric)
+        .take(len)
+        .collect::<String>()
+}

beacon_node/src/main.rs

@@ -1,12 +1,10 @@
+mod config;
 mod run;
 
-use clap::{App, Arg};
-use client::{ClientConfig, Eth2Config};
+use clap::{App, Arg, SubCommand};
+use config::get_configs;
 use env_logger::{Builder, Env};
-use eth2_config::{read_from_file, write_to_file};
 use slog::{crit, o, warn, Drain, Level};
-use std::fs;
-use std::path::PathBuf;
 
 pub const DEFAULT_DATA_DIR: &str = ".lighthouse";
 pub const CLIENT_CONFIG_FILENAME: &str = "beacon-node.toml";
@@ -30,36 +28,49 @@ fn main() {
                 .value_name("DIR")
                 .help("Data directory for keys and databases.")
                 .takes_value(true)
+                .global(true)
         )
         .arg(
             Arg::with_name("logfile")
                 .long("logfile")
-                .value_name("logfile")
+                .value_name("FILE")
                 .help("File path where output will be written.")
                 .takes_value(true),
         )
         .arg(
             Arg::with_name("network-dir")
                 .long("network-dir")
-                .value_name("NETWORK-DIR")
+                .value_name("DIR")
                 .help("Data directory for network keys.")
                 .takes_value(true)
+                .global(true)
         )
         /*
          * Network parameters.
          */
+        .arg(
+            Arg::with_name("port-bump")
+                .long("port-bump")
+                .short("b")
+                .value_name("INCREMENT")
+                .help("Sets all listening TCP/UDP ports to default values, but with each port increased by \
+                      INCREMENT. Useful when starting multiple nodes on a single machine. Using increments \
+                      in multiples of 10 is recommended.")
+                .takes_value(true),
+        )
         .arg(
             Arg::with_name("listen-address")
                 .long("listen-address")
                 .value_name("ADDRESS")
                 .help("The address lighthouse will listen for UDP and TCP connections. (default 127.0.0.1).")
-                .takes_value(true),
+                .takes_value(true)
         )
         .arg(
             Arg::with_name("port")
                 .long("port")
                 .value_name("PORT")
                 .help("The TCP/UDP port to listen on. The UDP port can be modified by the --discovery-port flag.")
+                .conflicts_with("port-bump")
                 .takes_value(true),
         )
         .arg(
@@ -72,7 +83,7 @@ fn main() {
             Arg::with_name("boot-nodes")
                 .long("boot-nodes")
                 .allow_hyphen_values(true)
-                .value_name("BOOTNODES")
+                .value_name("ENR-LIST")
                 .help("One or more comma-delimited base64-encoded ENR's to bootstrap the p2p network.")
                 .takes_value(true),
         )
@@ -81,6 +92,7 @@ fn main() {
                 .long("disc-port")
                 .value_name("PORT")
                 .help("The discovery UDP port.")
+                .conflicts_with("port-bump")
                 .takes_value(true),
         )
         .arg(
@@ -104,52 +116,93 @@ fn main() {
                 .help("One or more comma-delimited multiaddrs to manually connect to a libp2p peer without an ENR.")
                 .takes_value(true),
         )
+        .arg(
+            Arg::with_name("p2p-priv-key")
+                .long("p2p-priv-key")
+                .value_name("HEX")
+                .help("A secp256k1 secret key, represented as ASCII-encoded hex bytes (with or without 0x prefix).")
+                .takes_value(true),
+        )
         /*
          * gRPC parameters.
          */
         .arg(
-            Arg::with_name("rpc")
-                .long("rpc")
-                .value_name("RPC")
-                .help("Enable the RPC server.")
+            Arg::with_name("no-grpc")
+                .long("no-grpc")
+                .help("Disable the gRPC server.")
                 .takes_value(false),
         )
         .arg(
             Arg::with_name("rpc-address")
                 .long("rpc-address")
-                .value_name("Address")
+                .value_name("ADDRESS")
                 .help("Listen address for RPC endpoint.")
                 .takes_value(true),
         )
         .arg(
             Arg::with_name("rpc-port")
                 .long("rpc-port")
+                .value_name("PORT")
                 .help("Listen port for RPC endpoint.")
+                .conflicts_with("port-bump")
                 .takes_value(true),
         )
-        /* Client related arguments */
+        /* REST API related arguments */
         .arg(
-            Arg::with_name("api")
-                .long("api")
-                .value_name("API")
-                .help("Enable the RESTful HTTP API server.")
+            Arg::with_name("no-api")
+                .long("no-api")
+                .help("Disable RESTful HTTP API server.")
                 .takes_value(false),
         )
         .arg(
             Arg::with_name("api-address")
                 .long("api-address")
-                .value_name("APIADDRESS")
+                .value_name("ADDRESS")
                 .help("Set the listen address for the RESTful HTTP API server.")
                 .takes_value(true),
         )
         .arg(
             Arg::with_name("api-port")
                 .long("api-port")
-                .value_name("APIPORT")
+                .value_name("PORT")
                 .help("Set the listen TCP port for the RESTful HTTP API server.")
+                .conflicts_with("port-bump")
+                .takes_value(true),
+        )
+        /* Websocket related arguments */
+        .arg(
+            Arg::with_name("no-ws")
+                .long("no-ws")
+                .help("Disable websocket server.")
+                .takes_value(false),
+        )
+        .arg(
+            Arg::with_name("ws-address")
+                .long("ws-address")
+                .value_name("ADDRESS")
+                .help("Set the listen address for the websocket server.")
+                .conflicts_with_all(&["no-ws"])
+                .takes_value(true),
+        )
+        .arg(
+            Arg::with_name("ws-port")
+                .long("ws-port")
+                .value_name("PORT")
+                .help("Set the listen TCP port for the websocket server.")
+                .conflicts_with_all(&["no-ws", "port-bump"])
                 .takes_value(true),
         )
 
+        /*
+         * Eth1 Integration
+         */
+        .arg(
+            Arg::with_name("eth1-server")
+                .long("eth1-server")
+                .value_name("SERVER")
+                .help("Specifies the server for a web3 connection to the Eth1 chain.")
+                .takes_value(true)
+        )
         /*
          * Database parameters.
          */
@@ -160,25 +213,7 @@ fn main() {
                 .help("Type of database to use.")
                 .takes_value(true)
                 .possible_values(&["disk", "memory"])
-                .default_value("memory"),
-        )
-        /*
-         * Specification/testnet params.
-         */
-        .arg(
-            Arg::with_name("default-spec")
-                .long("default-spec")
-                .value_name("TITLE")
-                .short("default-spec")
-                .help("Specifies the default eth2 spec to be used. This will override any spec written to disk and will therefore be used by default in future instances.")
-                .takes_value(true)
-                .possible_values(&["mainnet", "minimal", "interop"])
-        )
-        .arg(
-            Arg::with_name("recent-genesis")
-                .long("recent-genesis")
-                .short("r")
-                .help("When present, genesis will be within 30 minutes prior. Only for testing"),
+                .default_value("disk"),
         )
         /*
          * Logging.
@@ -192,22 +227,138 @@ fn main() {
                 .possible_values(&["info", "debug", "trace", "warn", "error", "crit"])
                 .default_value("trace"),
         )
-        .arg(
-            Arg::with_name("verbosity")
-                .short("v")
-                .multiple(true)
-                .help("Sets the verbosity level")
-                .takes_value(true),
-        )
         /*
-         * Bootstrap.
+         * The "testnet" sub-command.
+         *
+         * Allows for creating a new datadir with testnet-specific configs.
          */
-        .arg(
-            Arg::with_name("bootstrap")
-                .long("bootstrap")
-                .value_name("HTTP_SERVER")
-                .help("Load the genesis state and libp2p address from the HTTP API of another Lighthouse node.")
-                .takes_value(true)
+        .subcommand(SubCommand::with_name("testnet")
+            .about("Create a new Lighthouse datadir using a testnet strategy.")
+            .arg(
+                Arg::with_name("spec")
+                    .short("s")
+                    .long("spec")
+                    .value_name("TITLE")
+                    .help("Specifies the default eth2 spec type. Only effective when creating a new datadir.")
+                    .takes_value(true)
+                    .required(true)
+                    .possible_values(&["mainnet", "minimal", "interop"])
+                    .default_value("minimal")
+            )
+            .arg(
+                Arg::with_name("eth2-config")
+                    .long("eth2-config")
+                    .value_name("TOML_FILE")
+                    .help("A existing eth2_spec TOML file (e.g., eth2_spec.toml).")
+                    .takes_value(true)
+                    .conflicts_with("spec")
+            )
+            .arg(
+                Arg::with_name("client-config")
+                    .long("client-config")
+                    .value_name("TOML_FILE")
+                    .help("An existing beacon_node TOML file (e.g., beacon_node.toml).")
+                    .takes_value(true)
+            )
+            .arg(
+                Arg::with_name("random-datadir")
+                    .long("random-datadir")
+                    .short("r")
+                    .help("If present, append a random string to the datadir path. Useful for fast development \
+                          iteration.")
+            )
+            .arg(
+                Arg::with_name("force")
+                    .long("force")
+                    .short("f")
+                    .help("If present, will create new config and database files and move the any existing to a \
+                           backup directory.")
+                    .conflicts_with("random-datadir")
+            )
+            .arg(
+                Arg::with_name("slot-time")
+                    .long("slot-time")
+                    .short("t")
+                    .value_name("MILLISECONDS")
+                    .help("Defines the slot time when creating a new testnet.")
+            )
+            /*
+             * `boostrap`
+             *
+             * Start a new node by downloading genesis and network info from another node via the
+             * HTTP API.
+             */
+            .subcommand(SubCommand::with_name("bootstrap")
+                .about("Connects to the given HTTP server, downloads a genesis state and attempts to peer with it.")
+                .arg(Arg::with_name("server")
+                    .value_name("HTTP_SERVER")
+                    .required(true)
+                    .default_value("http://localhost:5052")
+                    .help("A HTTP server, with a http:// prefix"))
+                .arg(Arg::with_name("libp2p-port")
+                    .short("p")
+                    .long("port")
+                    .value_name("TCP_PORT")
+                    .help("A libp2p listen port used to peer with the bootstrap server. This flag is useful \
+                           when port-fowarding is used: you may connect using a different port than \
+                           the one the server is immediately listening on."))
+            )
+            /*
+             * `recent`
+             *
+             * Start a new node, with a specified number of validators with a genesis time in the last
+             * 30-minutes.
+             */
+            .subcommand(SubCommand::with_name("recent")
+                .about("Creates a new genesis state where the genesis time was at the previous \
+                       MINUTES boundary (e.g., when MINUTES == 30; 12:00, 12:30, 13:00, etc.)")
+                .arg(Arg::with_name("validator_count")
+                    .value_name("VALIDATOR_COUNT")
+                    .required(true)
+                    .help("The number of validators in the genesis state"))
+                .arg(Arg::with_name("minutes")
+                    .long("minutes")
+                    .short("m")
+                    .value_name("MINUTES")
+                    .required(true)
+                    .default_value("15")
+                    .help("The maximum number of minutes that will have elapsed before genesis"))
+            )
+            /*
+             * `quick`
+             *
+             * Start a new node, specifying the number of validators and genesis time
+             */
+            .subcommand(SubCommand::with_name("quick")
+                .about("Creates a new genesis state from the specified validator count and genesis time. \
+                        Compatible with the `quick-start genesis` defined in the eth2.0-pm repo.")
+                .arg(Arg::with_name("validator_count")
+                    .value_name("VALIDATOR_COUNT")
+                    .required(true)
+                    .help("The number of validators in the genesis state"))
+                .arg(Arg::with_name("genesis_time")
+                    .value_name("UNIX_EPOCH_SECONDS")
+                    .required(true)
+                    .help("The genesis time for the given state."))
+            )
+            /*
+             * `yaml`
+             *
+             * Start a new node, using a genesis state loaded from a YAML file
+             */
+            .subcommand(SubCommand::with_name("file")
+                .about("Creates a new datadir where the genesis state is read from YAML. May fail to parse \
+                       a file that was generated to a different spec than that specified by --spec.")
+                .arg(Arg::with_name("format")
+                    .value_name("FORMAT")
+                    .required(true)
+                    .possible_values(&["yaml", "ssz", "json"])
+                    .help("The encoding of the state in the file."))
+                .arg(Arg::with_name("file")
+                    .value_name("YAML_FILE")
+                    .required(true)
+                    .help("A YAML file from which to read the state"))
+            )
         )
         .get_matches();
 
@@ -227,143 +378,34 @@ fn main() {
         _ => unreachable!("guarded by clap"),
     };
 
-    let mut log = slog::Logger::root(drain.fuse(), o!());
+    let log = slog::Logger::root(drain.fuse(), o!());
+
+    if std::mem::size_of::<usize>() != 8 {
+        crit!(
+            log,
+            "Lighthouse only supports 64bit CPUs";
+            "detected" => format!("{}bit", std::mem::size_of::<usize>() * 8)
+        );
+    }
 
     warn!(
         log,
         "Ethereum 2.0 is pre-release. This software is experimental."
     );
 
-    let data_dir = match matches
-        .value_of("datadir")
-        .and_then(|v| Some(PathBuf::from(v)))
-    {
-        Some(v) => v,
-        None => {
-            // use the default
-            let mut default_dir = match dirs::home_dir() {
-                Some(v) => v,
-                None => {
-                    crit!(log, "Failed to find a home directory");
-                    return;
-                }
-            };
-            default_dir.push(DEFAULT_DATA_DIR);
-            default_dir
-        }
-    };
+    let log_clone = log.clone();
 
-    // create the directory if needed
-    match fs::create_dir_all(&data_dir) {
-        Ok(_) => {}
-        Err(e) => {
-            crit!(log, "Failed to initialize data dir"; "error" => format!("{}", e));
-            return;
-        }
-    }
-
-    let client_config_path = data_dir.join(CLIENT_CONFIG_FILENAME);
-
-    // Attempt to load the `ClientConfig` from disk.
+    // Load the process-wide configuration.
     //
-    // If file doesn't exist, create a new, default one.
-    let mut client_config = match read_from_file::<ClientConfig>(client_config_path.clone()) {
-        Ok(Some(c)) => c,
-        Ok(None) => {
-            let default = ClientConfig::default();
-            if let Err(e) = write_to_file(client_config_path, &default) {
-                crit!(log, "Failed to write default ClientConfig to file"; "error" => format!("{:?}", e));
-                return;
-            }
-            default
-        }
+    // May load this from disk or create a new configuration, depending on the CLI flags supplied.
+    let (client_config, eth2_config, log) = match get_configs(&matches, log) {
+        Ok(configs) => configs,
         Err(e) => {
-            crit!(log, "Failed to load a ChainConfig file"; "error" => format!("{:?}", e));
+            crit!(log_clone, "Failed to load configuration. Exiting"; "error" => e);
             return;
         }
     };
 
-    // Ensure the `data_dir` in the config matches that supplied to the CLI.
-    client_config.data_dir = data_dir.clone();
-
-    // Update the client config with any CLI args.
-    match client_config.apply_cli_args(&matches, &mut log) {
-        Ok(()) => (),
-        Err(s) => {
-            crit!(log, "Failed to parse ClientConfig CLI arguments"; "error" => s);
-            return;
-        }
-    };
-
-    let eth2_config_path = data_dir.join(ETH2_CONFIG_FILENAME);
-
-    // Initialise the `Eth2Config`.
-    //
-    // If a CLI parameter is set, overwrite any config file present.
-    // If a parameter is not set, use either the config file present or default to minimal.
-    let cli_config = match matches.value_of("default-spec") {
-        Some("mainnet") => Some(Eth2Config::mainnet()),
-        Some("minimal") => Some(Eth2Config::minimal()),
-        Some("interop") => Some(Eth2Config::interop()),
-        _ => None,
-    };
-    // if a CLI flag is specified, write the new config if it doesn't exist,
-    // otherwise notify the user that the file will not be written.
-    let eth2_config_from_file = match read_from_file::<Eth2Config>(eth2_config_path.clone()) {
-        Ok(config) => config,
-        Err(e) => {
-            crit!(log, "Failed to read the Eth2Config from file"; "error" => format!("{:?}", e));
-            return;
-        }
-    };
-
-    let mut eth2_config = {
-        if let Some(cli_config) = cli_config {
-            if eth2_config_from_file.is_none() {
-                // write to file if one doesn't exist
-                if let Err(e) = write_to_file(eth2_config_path, &cli_config) {
-                    crit!(log, "Failed to write default Eth2Config to file"; "error" => format!("{:?}", e));
-                    return;
-                }
-            } else {
-                warn!(
-                    log,
-                    "Eth2Config file exists. Configuration file is ignored, using default"
-                );
-            }
-            cli_config
-        } else {
-            // CLI config not specified, read from disk
-            match eth2_config_from_file {
-                Some(config) => config,
-                None => {
-                    // set default to minimal
-                    let eth2_config = Eth2Config::minimal();
-                    if let Err(e) = write_to_file(eth2_config_path, &eth2_config) {
-                        crit!(log, "Failed to write default Eth2Config to file"; "error" => format!("{:?}", e));
-                        return;
-                    }
-                    eth2_config
-                }
-            }
-        }
-    };
-
-    // Update the eth2 config with any CLI flags.
-    match eth2_config.apply_cli_args(&matches) {
-        Ok(()) => (),
-        Err(s) => {
-            crit!(log, "Failed to parse Eth2Config CLI arguments"; "error" => s);
-            return;
-        }
-    };
-
-    // check to ensure the spec constants between the client and eth2_config match
-    if eth2_config.spec_constants != client_config.spec_constants {
-        crit!(log, "Specification constants do not match."; "client_config" => format!("{}", client_config.spec_constants), "eth2_config" => format!("{}", eth2_config.spec_constants));
-        return;
-    }
-
     // Start the node using a `tokio` executor.
     match run::run_beacon_node(client_config, eth2_config, &log) {
         Ok(_) => {}

beacon_node/src/run.rs

@@ -1,19 +1,17 @@
-use client::{
-    error, notifier, BeaconChainTypes, Client, ClientConfig, ClientType, Eth2Config,
-    InitialiseBeaconChain,
-};
+use client::{error, notifier, Client, ClientConfig, Eth1BackendMethod, Eth2Config};
 use futures::sync::oneshot;
 use futures::Future;
 use slog::{error, info};
 use std::cell::RefCell;
 use std::path::Path;
 use std::path::PathBuf;
+use store::Store;
 use store::{DiskStore, MemoryStore};
 use tokio::runtime::Builder;
 use tokio::runtime::Runtime;
 use tokio::runtime::TaskExecutor;
 use tokio_timer::clock::Clock;
-use types::{InteropEthSpec, MainnetEthSpec, MinimalEthSpec};
+use types::{EthSpec, InteropEthSpec, MainnetEthSpec, MinimalEthSpec};
 
 /// Reads the configuration and initializes a `BeaconChain` with the required types and parameters.
 ///
@@ -44,63 +42,29 @@ pub fn run_beacon_node(
 
     info!(
         log,
-        "BeaconNode init";
-        "p2p_listen_address" => format!("{:?}", &other_client_config.network.listen_address),
-        "data_dir" => format!("{:?}", other_client_config.data_dir()),
-        "network_dir" => format!("{:?}", other_client_config.network.network_dir),
-        "spec_constants" => &spec_constants,
+        "Starting beacon node";
+        "p2p_listen_address" => format!("{}", &other_client_config.network.listen_address),
         "db_type" => &other_client_config.db_type,
+        "spec_constants" => &spec_constants,
     );
 
+    macro_rules! run_client {
+        ($store: ty, $eth_spec: ty) => {
+            run::<$store, $eth_spec>(&db_path, client_config, eth2_config, executor, runtime, log)
+        };
+    }
+
+    if let Eth1BackendMethod::Web3 { .. } = client_config.eth1_backend_method {
+        return Err("Starting from web3 backend is not supported for interop.".into());
+    }
+
     match (db_type.as_str(), spec_constants.as_str()) {
-        ("disk", "minimal") => run::<ClientType<DiskStore, MinimalEthSpec>>(
-            &db_path,
-            client_config,
-            eth2_config,
-            executor,
-            runtime,
-            log,
-        ),
-        ("memory", "minimal") => run::<ClientType<MemoryStore, MinimalEthSpec>>(
-            &db_path,
-            client_config,
-            eth2_config,
-            executor,
-            runtime,
-            log,
-        ),
-        ("disk", "mainnet") => run::<ClientType<DiskStore, MainnetEthSpec>>(
-            &db_path,
-            client_config,
-            eth2_config,
-            executor,
-            runtime,
-            log,
-        ),
-        ("memory", "mainnet") => run::<ClientType<MemoryStore, MainnetEthSpec>>(
-            &db_path,
-            client_config,
-            eth2_config,
-            executor,
-            runtime,
-            log,
-        ),
-        ("disk", "interop") => run::<ClientType<DiskStore, InteropEthSpec>>(
-            &db_path,
-            client_config,
-            eth2_config,
-            executor,
-            runtime,
-            log,
-        ),
-        ("memory", "interop") => run::<ClientType<MemoryStore, InteropEthSpec>>(
-            &db_path,
-            client_config,
-            eth2_config,
-            executor,
-            runtime,
-            log,
-        ),
+        ("disk", "minimal") => run_client!(DiskStore, MinimalEthSpec),
+        ("disk", "mainnet") => run_client!(DiskStore, MainnetEthSpec),
+        ("disk", "interop") => run_client!(DiskStore, InteropEthSpec),
+        ("memory", "minimal") => run_client!(MemoryStore, MinimalEthSpec),
+        ("memory", "mainnet") => run_client!(MemoryStore, MainnetEthSpec),
+        ("memory", "interop") => run_client!(MemoryStore, InteropEthSpec),
         (db_type, spec) => {
             error!(log, "Unknown runtime configuration"; "spec_constants" => spec, "db_type" => db_type);
             Err("Unknown specification and/or db_type.".into())
@@ -109,7 +73,7 @@ pub fn run_beacon_node(
 }
 
 /// Performs the type-generic parts of launching a `BeaconChain`.
-fn run<T>(
+fn run<S, E>(
     db_path: &Path,
     client_config: ClientConfig,
     eth2_config: Eth2Config,
@@ -118,12 +82,13 @@ fn run<T>(
     log: &slog::Logger,
 ) -> error::Result<()>
 where
-    T: BeaconChainTypes + InitialiseBeaconChain<T> + Clone,
-    T::Store: OpenDatabase,
+    S: Store + Clone + 'static + OpenDatabase,
+    E: EthSpec,
 {
-    let store = T::Store::open_database(&db_path)?;
+    let store = S::open_database(&db_path)?;
 
-    let client: Client<T> = Client::new(client_config, eth2_config, store, log.clone(), &executor)?;
+    let client: Client<S, E> =
+        Client::new(client_config, eth2_config, store, log.clone(), &executor)?;
 
     // run service until ctrl-c
     let (ctrlc_send, ctrlc_oneshot) = oneshot::channel();

beacon_node/websocket_server/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "websocket_server"
+version = "0.1.0"
+authors = ["Paul Hauner <paul@paulhauner.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+beacon_chain = { path = "../beacon_chain" }
+clap = "2.32.0"
+exit-future = "0.1.3"
+futures = "0.1.25"
+serde = "1.0"
+serde_derive = "1.0"
+serde_json = "^1.0"
+slog = "^2.2.3"
+tokio = "0.1.16"
+types = { path = "../../eth2/types" }
+ws = "0.9"

beacon_node/websocket_server/src/config.rs

@@ -0,0 +1,45 @@
+use clap::ArgMatches;
+use serde::{Deserialize, Serialize};
+use std::net::Ipv4Addr;
+
+/// The core configuration of a Lighthouse beacon node.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Config {
+    pub enabled: bool,
+    /// The IPv4 address the REST API HTTP server will listen on.
+    pub listen_address: Ipv4Addr,
+    /// The port the REST API HTTP server will listen on.
+    pub port: u16,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Config {
+            enabled: true,
+            listen_address: Ipv4Addr::new(127, 0, 0, 1),
+            port: 5053,
+        }
+    }
+}
+
+impl Config {
+    pub fn apply_cli_args(&mut self, args: &ArgMatches) -> Result<(), &'static str> {
+        if args.is_present("no-ws") {
+            self.enabled = false;
+        }
+
+        if let Some(rpc_address) = args.value_of("ws-address") {
+            self.listen_address = rpc_address
+                .parse::<Ipv4Addr>()
+                .map_err(|_| "ws-address is not a valid IPv4 address.")?;
+        }
+
+        if let Some(rpc_port) = args.value_of("ws-port") {
+            self.port = rpc_port
+                .parse::<u16>()
+                .map_err(|_| "ws-port is not a valid u16.")?;
+        }
+
+        Ok(())
+    }
+}

beacon_node/websocket_server/src/lib.rs

@@ -0,0 +1,117 @@
+use beacon_chain::events::{EventHandler, EventKind};
+use futures::Future;
+use slog::{debug, error, info, warn, Logger};
+use std::marker::PhantomData;
+use std::thread;
+use tokio::runtime::TaskExecutor;
+use types::EthSpec;
+use ws::{Sender, WebSocket};
+
+mod config;
+
+pub use config::Config;
+
+pub struct WebSocketSender<T: EthSpec> {
+    sender: Option<Sender>,
+    _phantom: PhantomData<T>,
+}
+
+impl<T: EthSpec> WebSocketSender<T> {
+    /// Creates a dummy websocket server that never starts and where all future calls are no-ops.
+    pub fn dummy() -> Self {
+        Self {
+            sender: None,
+            _phantom: PhantomData,
+        }
+    }
+
+    pub fn send_string(&self, string: String) -> Result<(), String> {
+        if let Some(sender) = &self.sender {
+            sender
+                .send(string)
+                .map_err(|e| format!("Unable to broadcast to websocket clients: {:?}", e))
+        } else {
+            Ok(())
+        }
+    }
+}
+
+impl<T: EthSpec> EventHandler<T> for WebSocketSender<T> {
+    fn register(&self, kind: EventKind<T>) -> Result<(), String> {
+        self.send_string(
+            serde_json::to_string(&kind)
+                .map_err(|e| format!("Unable to serialize event: {:?}", e))?,
+        )
+    }
+}
+
+pub fn start_server<T: EthSpec>(
+    config: &Config,
+    executor: &TaskExecutor,
+    log: &Logger,
+) -> Result<(WebSocketSender<T>, exit_future::Signal), String> {
+    let server_string = format!("{}:{}", config.listen_address, config.port);
+
+    info!(
+        log,
+        "Websocket server starting";
+        "listen_address" => &server_string
+    );
+
+    // Create a server that simply ignores any incoming messages.
+    let server = WebSocket::new(|_| |_| Ok(()))
+        .map_err(|e| format!("Failed to initialize websocket server: {:?}", e))?;
+
+    let broadcaster = server.broadcaster();
+
+    // Produce a signal/channel that can gracefully shutdown the websocket server.
+    let exit_signal = {
+        let (exit_signal, exit) = exit_future::signal();
+
+        let log_inner = log.clone();
+        let broadcaster_inner = server.broadcaster();
+        let exit_future = exit.and_then(move |_| {
+            if let Err(e) = broadcaster_inner.shutdown() {
+                warn!(
+                    log_inner,
+                    "Websocket server errored on shutdown";
+                    "error" => format!("{:?}", e)
+                );
+            } else {
+                info!(log_inner, "Websocket server shutdown");
+            }
+            Ok(())
+        });
+
+        // Place a future on the executor that will shutdown the websocket server when the
+        // application exits.
+        executor.spawn(exit_future);
+
+        exit_signal
+    };
+
+    let log_inner = log.clone();
+    let _handle = thread::spawn(move || match server.listen(server_string) {
+        Ok(_) => {
+            debug!(
+                log_inner,
+                "Websocket server thread stopped";
+            );
+        }
+        Err(e) => {
+            error!(
+                log_inner,
+                "Websocket server failed to start";
+                "error" => format!("{:?}", e)
+            );
+        }
+    });
+
+    Ok((
+        WebSocketSender {
+            sender: Some(broadcaster),
+            _phantom: PhantomData,
+        },
+        exit_signal,
+    ))
+}

book/.gitignore

@@ -0,0 +1 @@
+book

book/book.toml

@@ -0,0 +1,6 @@
+[book]
+authors = ["Paul Hauner"]
+language = "en"
+multilingual = false
+src = "src"
+title = "Lighthouse"

book/src/SUMMARY.md

@@ -0,0 +1,11 @@
+# Summary
+
+* [Introduction](./intro.md)
+* [Development Environment](./setup.md)
+* [Websocket Interface](./websockets.md)
+* [Simple Local Testnet](./simple-testnet.md)
+* [Interop](./interop.md)
+    * [Environment](./interop-environment.md)
+    * [CLI Overview](./interop-cli.md)
+    * [Scenarios](./interop-scenarios.md)
+    * [Cheat-sheet](./interop-cheat-sheet.md)

book/src/interop-cheat-sheet.md

@@ -0,0 +1,149 @@
+# Interop Cheat-sheet
+
+This document contains a list of tips and tricks that may be useful during
+interop testing.
+
+- When starting a beacon node:
+	- [Specify a boot node by multiaddr](#boot-node-multiaddr)
+	- [Specify a boot node by ENR](#boot-node-enr)
+	- [Avoid port clashes when starting multiple nodes](#port-bump)
+	- [Specify a custom slot time](#slot-time)
+- Using the beacon node HTTP API:
+	- [Pretty-print the genesis state and state root](#http-state)
+	- [Curl a node's ENR](#http-enr)
+	- [Curl a node's connected peers](#http-peer-ids)
+	- [Curl a node's local peer id](#http-peer-id)
+	- [Curl a node's listening multiaddrs](#http-listen-addresses)
+	- [Curl a node's beacon chain head](#http-head)
+	- [Curl a node's finalized checkpoint](#http-finalized)
+
+## Category: CLI
+
+The `--help` command provides detail on the CLI interface. Here are some
+interop-specific CLI commands.
+
+<a name="boot-node-multiaddr"></a>
+### Specify a boot node by multiaddr
+
+You can specify a static list of multiaddrs when booting Lighthouse using
+the `--libp2p-addresses` command.
+
+#### Example:
+
+```
+$ ./beacon_node --libp2p-addresses /ip4/192.168.0.1/tcp/9000
+```
+
+<a name="boot-node-enr"></a>
+### Specify a boot node by ENR
+
+You can specify a static list of Discv5 addresses when booting Lighthouse using
+the `--boot-nodes` command.
+
+#### Example:
+
+```
+$ ./beacon_node --boot-nodes -IW4QB2Hi8TPuEzQ41Cdf1r2AUU1FFVFDBJdJyOkWk2qXpZfFZQy2YnJIyoT_5fnbtrXUouoskmydZl4pIg90clIkYUDgmlwhH8AAAGDdGNwgiMog3VkcIIjKIlzZWNwMjU2azGhAjg0-DsTkQynhJCRnLLttBK1RS78lmUkLa-wgzAi-Ob5
+```
+
+<a name="port-bump"></a>
+### Avoid port clashes when starting nodes
+
+Starting a second Lighthouse node on the same machine will fail due to TCP/UDP
+port collisions. Use the `-b` (`--port-bump`) flag to increase all listening
+ports by some `n`.
+
+#### Example:
+
+Increase all ports by `10` (using multiples of `10` is recommended).
+
+```
+$ ./beacon_node -b 10
+```
+
+<a name="slot-time"></a>
+### Start a testnet with a custom slot time
+
+Lighthouse can run at quite low slot times when there are few validators (e.g.,
+`500 ms` slot times should be fine for 8 validators).
+
+#### Example
+
+The `-t` (`--slot-time`) flag specifies the milliseconds per slot.
+
+```
+$ ./beacon_node testnet -t 500 recent 8
+```
+
+> Note: `bootstrap` loads the slot time via HTTP and therefore conflicts with
+> this flag.
+
+## Category: HTTP API
+
+Examples assume there is a Lighthouse node exposing a HTTP API on
+`localhost:5052`. Responses are JSON.
+
+<a name="http-state"></a>
+### Pretty-print the genesis state and state root
+
+Returns the genesis state and state root in your terminal, in YAML.
+
+```
+$ curl --header "Content-Type: application/yaml" "localhost:5052/beacon/state?slot=0"
+```
+
+<a name="http-enr"></a>
+### Get the node's ENR
+
+```
+$ curl localhost:5052/network/enr
+
+"-IW4QFyf1VlY5pZs0xZuvKMRZ9_cdl9WMCDAAJXZiZiuGcfRYoU40VPrYDLQj5prneJIz3zcbTjHp9BbThc-yiymJO8HgmlwhH8AAAGDdGNwgiMog3VkcIIjKIlzZWNwMjU2azGhAjg0-DsTkQynhJCRnLLttBK1RS78lmUkLa-wgzAi-Ob5"%
+```
+
+<a name="http-peer-ids"></a>
+### Get a list of connected peer ids
+
+```
+$ curl localhost:5052/network/peers
+
+["QmeMFRTWfo3KbVG7dEBXGhyRMa29yfmnJBXW84rKuGEhuL"]%
+```
+
+<a name="http-peer-id"></a>
+### Get the node's peer id
+
+```
+curl localhost:5052/network/peer_id
+
+"QmRD1qs2AqNNRdBcGHUGpUGkpih5cmdL32mhh22Sy79xsJ"%
+```
+
+<a name="http-listen-addresses"></a>
+### Get the list of listening libp2p addresses
+
+Lists all the libp2p multiaddrs that the node is listening on.
+
+```
+curl localhost:5052/network/listen_addresses
+
+["/ip4/127.0.0.1/tcp/9000","/ip4/192.168.1.121/tcp/9000","/ip4/172.17.0.1/tcp/9000","/ip4/172.42.0.1/tcp/9000","/ip6/::1/tcp/9000","/ip6/fdd3:c293:1bc::203/tcp/9000","/ip6/fdd3:c293:1bc:0:9aa9:b2ea:c610:44db/tcp/9000"]%
+```
+
+<a name="http-head"></a>
+### Get the node's beacon chain head
+
+```
+curl localhost:5052/beacon/head
+
+{"slot":0,"block_root":"0x827bf71805540aa13f6d8c7d18b41b287b2094a4d7a28cbb8deb061dbf5df4f5","state_root":"0x90a78d73294bc9c7519a64e1912161be0e823eb472012ff54204e15a4d717fa5"}%
+```
+
+<a name="http-finalized"></a>
+### Get the node's finalized checkpoint
+
+```
+curl localhost:5052/beacon/latest_finalized_checkpoint
+
+{"epoch":0,"root":"0x0000000000000000000000000000000000000000000000000000000000000000"}%
+```

book/src/interop-cli.md

@@ -0,0 +1,29 @@
+# Interop CLI Overview
+
+The Lighthouse CLI has two primary tasks:
+
+- **Resuming** an existing database with `$ ./beacon_node`.
+- **Creating** a new testnet database using `$ ./beacon_node testnet`.
+
+_See [Scenarios](./interop-scenarios.md) for methods we've anticipated will be
+used interop._
+
+## Creating a new database
+
+There are several methods for creating a new beacon node database:
+
+- `quick`: using the `(validator_client, genesis_time)` tuple.
+- `recent`: as above but `genesis_time` is set to the start of some recent time
+	window.
+- `file`: loads the genesis file from disk in one of multiple formats.
+- `bootstrap`: a Lighthouse-specific method where we connect to a running node
+	and download it's specification and genesis state via the HTTP API.
+
+See `$ ./beacon_node testnet --help` for more detail.
+
+## Resuming from an existing database
+
+Once a database has been created, it can be resumed by running `$ ./beacon_node`.
+
+Presently, this command will fail if no existing database is found. You must
+use the `$ ./beacon_node testnet` command to create a new database.

book/src/interop-environment.md

@@ -0,0 +1,30 @@
+# Interop Environment
+
+All that is required for inter-op is a built and tested [development
+environment](./setup.md).
+
+## Repositories
+
+You will only require the [sigp/lighthouse](http://github.com/sigp/lighthouse)
+library.
+
+To allow for faster build/test iterations we will use the
+[`interop`](https://github.com/sigp/lighthouse/tree/interop) branch of
+[sigp/lighthouse](https://github.com/sigp/lighthouse/tree/interop) for
+September 2019 interop.  **Please use ensure you `git checkout interop` after
+cloning the repo.**
+
+## File System
+
+When lighthouse boots, it will create the following
+directories:
+
+- `~/.lighthouse`: database and configuration for the beacon node.
+- `~/.lighthouse-validator`: database and configuration for the validator
+	client.
+
+After building the binaries with `cargo build --release --all`, there will be a
+`target/release` directory in the root of the Lighthouse repository. This is
+where the `beacon_node` and `validator_client` binaries are located.
+
+You do not need to create any of these directories manually.

book/src/interop-scenarios.md

@@ -0,0 +1,101 @@
+# Interop Scenarios
+
+Here we demonstrate some expected interop scenarios.
+
+All scenarios assume a working [development environment](./setup.md) and
+commands are based in the `target/release` directory (this is the build dir for
+`cargo`).
+
+Additional functions can be found in the [interop
+cheat-sheet](./interop-cheat-sheet.md).
+
+### Table of contents
+
+- [Starting from a`validator_count, genesis_time` tuple](#quick-start)
+- [Starting a node from a genesis state file](#state-file)
+- [Starting a validator client](#val-client)
+- [Exporting a genesis state file](#export) from a running Lighthouse
+	node
+
+
+<a name="quick-start"></a>
+### Start beacon node given a validator count and genesis_time
+
+
+To start a brand-new beacon node (with no history) use:
+
+```
+$ ./beacon_node testnet -f quick 8 <GENESIS_TIME>
+```
+
+Where `GENESIS_TIME` is in [unix time](https://duckduckgo.com/?q=unix+time&t=ffab&ia=answer).
+
+> Notes:
+>
+> - This method conforms the ["Quick-start
+genesis"](https://github.com/ethereum/eth2.0-pm/tree/6e41fcf383ebeb5125938850d8e9b4e9888389b4/interop/mocked_start#quick-start-genesis)
+method in the `ethereum/eth2.0-pm` repository.
+> - The `-f` flag ignores any existing database or configuration, backing them
+>   up before re-initializing.
+> - `8` is the validator count and `1567222226` is the genesis time.
+> - See `$ ./beacon_node testnet quick --help` for more configuration options.
+
+<a name="state-file"></a>
+### Start Beacon Node given a genesis state file
+
+A genesis state can be read from file using the `testnet file` subcommand.
+There are three supported formats:
+
+- `ssz` (default)
+- `json`
+- `yaml`
+
+Start a new node using `/tmp/genesis.ssz` as the genesis state:
+
+```
+$ ./beacon_node testnet --spec minimal -f file ssz /tmp/genesis.ssz
+```
+
+> Notes:
+>
+> - The `-f` flag ignores any existing database or configuration, backing them
+>   up before re-initializing.
+> - See `$ ./beacon_node testnet file --help` for more configuration options.
+> - The `--spec` flag is required to allow SSZ parsing of fixed-length lists.
+
+<a name="val-client"></a>
+### Start an auto-configured validator client
+
+To start a brand-new validator client (with no history) use:
+
+```
+$ ./validator_client testnet -b insecure 0 8
+```
+
+> Notes:
+>
+> - The `-b` flag means the validator client will "bootstrap" specs and config
+>   from the beacon node.
+> - The `insecure` command dictates that the [interop keypairs](https://github.com/ethereum/eth2.0-pm/tree/6e41fcf383ebeb5125938850d8e9b4e9888389b4/interop/mocked_start#pubkeyprivkey-generation)
+>   will be used.
+> - The `0 8` indicates that this validator client should manage 8 validators,
+>   starting at validator 0 (the first deposited validator).
+> - The validator client will try to connect to the beacon node at `localhost`.
+>   See `--help` to configure that address and other features.
+> - The validator client will operate very unsafely in `testnet` mode, happily
+>   swapping between chains and creating double-votes.
+
+<a name="export"></a>
+### Exporting a genesis file
+
+Genesis states can downloaded from a running Lighthouse node via the HTTP API. Three content-types are supported:
+
+- `application/json`
+- `application/yaml`
+- `application/ssz`
+
+Using `curl`, a genesis state can be downloaded to `/tmp/genesis.ssz`:
+
+```
+$ curl --header "Content-Type: application/ssz" "localhost:5052/beacon/state/genesis" -o /tmp/genesis.ssz
+```

book/src/interop.md

@@ -0,0 +1,11 @@
+# Lighthouse Interop Guide
+
+This guide is intended for other Ethereum 2.0 client developers performing
+inter-operability testing with Lighthouse.
+
+## Chapters
+
+- Read about the required [development environment](./interop-environment.md).
+- Get an [overview](./interop-cli.md) of the Lighthouse CLI.
+- See how we expect to handle some [interop scenarios](./interop-scenarios.md).
+- See the [interop cheat-sheet](./interop-cheat-sheet.md) for useful CLI tips.

book/src/intro.md

@@ -0,0 +1,27 @@
+# Lighthouse Documentation
+
+[![Build Status]][Build Link] [![Doc Status]][Doc Link] [![Chat Badge]][Chat Link]
+
+[Build Status]: https://gitlab.sigmaprime.io/sigp/lighthouse/badges/master/build.svg
+[Build Link]: https://gitlab.sigmaprime.io/sigp/lighthouse/pipelines
+[Chat Badge]: https://img.shields.io/badge/chat-discord-%237289da
+[Chat Link]: https://discord.gg/cyAszAh
+[Doc Status]:https://img.shields.io/badge/rust--docs-master-orange
+[Doc Link]: http://lighthouse-docs.sigmaprime.io/
+
+Lighthouse is an **Ethereum 2.0 client** that connects to other Ethereum 2.0
+clients to form a resilient and decentralized proof-of-stake blockchain.
+
+It is written in Rust, maintained by Sigma Prime and funded by the Ethereum
+Foundation, Consensys and other individuals and organisations.
+
+## Developer Resources
+
+Documentation is presently targeted at **researchers and developers**. It
+assumes significant prior knowledge of Ethereum 2.0.
+
+Topics:
+
+- Get started with [development environment setup](./setup.md).
+- See the [interop docs](./interop.md).
+- [Run a simple testnet](./simple-testnet.md) in Only Three CLI Commands™.

book/src/setup.md

@@ -0,0 +1,81 @@
+# Development Environment Setup
+
+Follow this guide to get a Lighthouse development environment up-and-running.
+
+See the [Quick instructions](#quick-instructions) for a summary or the
+[Detailed instructions](#detailed-instructions) for clarification.
+
+## Quick instructions
+
+1. Install Rust + Cargo with [rustup](https://rustup.rs/).
+1. Install build dependencies using your package manager.
+    - `$ <package-manager> clang protobuf libssl-dev cmake`
+1. Clone the [sigp/lighthouse](https://github.com/sigp/lighthouse).
+1. In the root of the repo, run the tests with `cargo test --all --release`.
+1. Then, build the binaries with `cargo build --all --release`.
+1. Lighthouse is now fully built and tested.
+
+_Note: first-time compilation may take several minutes._
+
+## Detailed instructions
+
+A fully-featured development environment can be achieved with the following
+steps:
+
+   1. Install [rustup](https://rustup.rs/).
+   1. Use the command `rustup show` to get information about the Rust
+	  installation. You should see that the active tool-chain is the stable
+	  version.
+	  - Updates can be performed using` rustup update`, Lighthouse generally
+		  requires a recent version of Rust.
+   1. Install build dependencies (Arch packages are listed here, your
+   distribution will likely be similar):
+	  - `clang`: required by RocksDB.
+	  - `protobuf`: required for protobuf serialization (gRPC)
+      - `libssl-dev`: also gRPC
+	  - `cmake`: required for building protobuf
+   1. Clone the repository with submodules: `git clone
+	  https://github.com/sigp/lighthouse`.
+   1. Change directory to the root of the repository.
+   1. Run the test suite with `cargo test --all --release`. The build and test
+	  process can take several minutes. If you experience any failures on
+	  `master`, please raise an
+	  [issue](https://github.com/sigp/lighthouse/issues).
+
+### Notes:
+
+Lighthouse targets Rust `stable` but generally runs on `nightly` too.
+
+#### Note for Windows users:
+
+Perl may also be required to build lighthouse. You can install [Strawberry
+Perl](http://strawberryperl.com/), or alternatively use a choco install command
+`choco install strawberryperl`.
+
+Additionally, the dependency `protoc-grpcio v0.3.1` is reported to have issues
+compiling in Windows. You can specify a known working version by editing
+version in `protos/Cargo.toml`  section to `protoc-grpcio = "<=0.3.0"`.
+
+## eth2.0-spec-tests
+
+The
+[ethereum/eth2.0-spec-tests](https://github.com/ethereum/eth2.0-spec-tests/)
+repository contains a large set of tests that verify Lighthouse behaviour
+against the Ethereum Foundation specifications.
+
+The `tests/ef_tests` crate runs these tests and it has some interesting
+behaviours:
+
+- If the `tests/ef_tests/eth2.0-spec-tests` directory is not present, all tests
+	indicate a `pass` when they did not actually run.
+- If that directory _is_ present, the tests are executed faithfully, failing if
+	a discrepancy is found.
+
+The `tests/ef_tests/eth2.0-spec-tests` directory is not present by default. To
+obtain it, use the Makefile in the root of the repository:
+
+```
+make ef_tests
+```
+
+_Note: this will download 100+ MB of test files from the [ethereum/eth2.0-spec-tests](https://github.com/ethereum/eth2.0-spec-tests/)._

book/src/simple-testnet.md

@@ -0,0 +1,81 @@
+# Simple Local Testnet
+
+You can setup a local, two-node testnet in **Only Three CLI Commands™**.
+
+Follow the [Quick instructions](#tldr) version if you're confident, or see
+[Detailed instructions](#detail) for more.
+
+
+## Quick instructions
+
+Setup a development environment, build the project and navigate to the
+`target/release` directory.
+
+1. Start the first node: `$ ./beacon_node testnet -f recent 8`
+1. Start a validator client: `$ ./validator_client testnet -b insecure 0 8`
+1. Start another node `$ ./beacon_node -b 10 testnet -f bootstrap http://localhost:5052`
+
+_Repeat #3 to add more nodes._
+
+## Detailed instructions
+
+First, setup a Lighthouse development environment and navigate to the
+`target/release` directory (this is where the binaries are located).
+
+## Starting the Beacon Node
+
+Start a new node (creating a fresh database and configuration in `~/.lighthouse`), using:
+
+```
+$ ./beacon_node testnet -f recent 8
+```
+
+> Notes:
+>
+> - The `-f` flag ignores any existing database or configuration, backing them
+>   up before re-initializing.
+> - `8` is number of validators with deposits in the genesis state.
+> - See `$ ./beacon_node testnet recent --help` for more configuration options,
+>   including `minimal`/`mainnet` specification.
+
+## Starting the Validator Client
+
+In a new terminal window, start the validator client with:
+
+```
+$ ./validator_client testnet -b insecure 0 8
+```
+
+> Notes:
+>
+> - The `-b` flag means the validator client will "bootstrap" specs and config
+>   from the beacon node.
+> - The `insecure` command uses predictable, well-known private keys. Since
+>   this is just a local testnet, these are fine.
+> - The `0 8` indicates that this validator client should manage 8 validators,
+>   starting at validator 0 (the first deposited validator).
+> - The validator client will try to connect to the beacon node at `localhost`.
+>   See `--help` to configure that address and other features.
+
+## Adding another Beacon Node
+
+You may connect another (non-validating) node to your local network using the
+lighthouse `bootstrap` command.
+
+In a new terminal terminal, run:
+
+
+```
+$ ./beacon_node -b 10 testnet -r bootstrap
+```
+
+> Notes:
+>
+> - The `-b` (or `--port-bump`) increases all the listening TCP/UDP ports of
+>   the new node to `10` higher. Your first node's HTTP server was at TCP
+>   `5052` but this one will be at `5062`.
+> - The `-r` flag creates a new data directory with a random string appended
+>   (avoids data directory collisions between nodes).
+> - The default bootstrap HTTP address is `http://localhost:5052`. The new node
+>   will download configuration via HTTP before starting sync via libp2p.
+> - See `$ ./beacon_node testnet bootstrap --help` for more configuration.

book/src/testnets.md

@@ -0,0 +1,10 @@
+# Testnets
+
+Lighthouse does not offer a public testnet _yet_. In the meantime, it's easy to
+start a local testnet:
+
+- [Run a simple testnet](testnets.html) in Only Three CLI Commands™.
+- Developers of other Eth2 clients should see the [interop guide](interop.html).
+- The [sigp/lighthouse-docker](https://github.com/sigp/lighthouse-docker) repo
+	contains a `docker-compose` setup that runs a multi-node network with
+	built-in metrics and monitoring dashboards, all from your local machine.

book/src/websockets.md

@@ -0,0 +1,108 @@
+# Websocket Interface
+
+By default, a Lighthouse `beacon_node` exposes a websocket server on `localhost:5053`.
+
+The following CLI flags control the websocket server:
+
+- `--no-ws`: disable the websocket server.
+- `--ws-port`: specify the listen port of the server.
+- `--ws-address`: specify the listen address of the server.
+
+All clients connected to the websocket server will receive the same stream of events, all triggered
+by the `BeaconChain`. Each event is a JSON object with the following schema:
+
+```json
+{
+    "event": "string",
+    "data": "object"
+}
+```
+
+## Events
+
+The following events may be emitted:
+
+### Beacon Head Changed
+
+Occurs whenever the canonical head of the beacon chain changes.
+
+```json
+{
+    "event": "beacon_head_changed",
+    "data": {
+        "reorg": "boolean",
+        "current_head_beacon_block_root": "string",
+        "previous_head_beacon_block_root": "string"
+    }
+}
+```
+
+### Beacon Finalization
+
+Occurs whenever the finalized checkpoint of the canonical head changes.
+
+```json
+{
+    "event": "beacon_finalization",
+    "data": {
+        "epoch": "number",
+        "root": "string"
+    }
+}
+```
+
+### Beacon Block Imported
+
+Occurs whenever the beacon node imports a valid block.
+
+```json
+{
+    "event": "beacon_block_imported",
+    "data": {
+        "block": "object"
+    }
+}
+```
+
+### Beacon Block Rejected
+
+Occurs whenever the beacon node rejects a block because it is invalid or an
+error occurred during validation.
+
+```json
+{
+    "event": "beacon_block_rejected",
+    "data": {
+        "reason": "string",
+        "block": "object"
+    }
+}
+```
+
+### Beacon Attestation Imported
+
+Occurs whenever the beacon node imports a valid attestation.
+
+```json
+{
+    "event": "beacon_attestation_imported",
+    "data": {
+        "attestation": "object"
+    }
+}
+```
+
+### Beacon Attestation Rejected
+
+Occurs whenever the beacon node rejects an attestation because it is invalid or
+an error occurred during validation.
+
+```json
+{
+    "event": "beacon_attestation_rejected",
+    "data": {
+        "reason": "string",
+        "attestation": "object"
+    }
+}
+```

eth2/lmd_ghost/src/lib.rs

@@ -46,4 +46,10 @@ pub trait LmdGhost<S: Store, E: EthSpec>: Send + Sync {
 
     /// Returns the latest message for a given validator index.
     fn latest_message(&self, validator_index: usize) -> Option<(Hash256, Slot)>;
+
+    /// Runs an integrity verification function on fork choice algorithm.
+    ///
+    /// Returns `Ok(())` if the underlying fork choice has maintained it's integrity,
+    /// `Err(description)` otherwise.
+    fn verify_integrity(&self) -> Result<()>;
 }

eth2/lmd_ghost/src/reduced_tree.rs

@@ -43,16 +43,6 @@ impl<T, E> fmt::Debug for ThreadSafeReducedTree<T, E> {
     }
 }
 
-impl<T, E> ThreadSafeReducedTree<T, E>
-where
-    T: Store,
-    E: EthSpec,
-{
-    pub fn verify_integrity(&self) -> std::result::Result<(), String> {
-        self.core.read().verify_integrity()
-    }
-}
-
 impl<T, E> LmdGhost<T, E> for ThreadSafeReducedTree<T, E>
 where
     T: Store,
@@ -80,7 +70,7 @@ where
     fn process_block(&self, block: &BeaconBlock<E>, block_hash: Hash256) -> SuperResult<()> {
         self.core
             .write()
-            .add_weightless_node(block.slot, block_hash)
+            .maybe_add_weightless_node(block.slot, block_hash)
             .map_err(|e| format!("process_block failed: {:?}", e))
     }
 
@@ -113,6 +103,10 @@ where
     fn latest_message(&self, validator_index: usize) -> Option<(Hash256, Slot)> {
         self.core.read().latest_message(validator_index)
     }
+
+    fn verify_integrity(&self) -> std::result::Result<(), String> {
+        self.core.read().verify_integrity()
+    }
 }
 
 struct ReducedTree<T, E> {
@@ -163,15 +157,7 @@ where
     /// The given `new_root` must be in the block tree (but not necessarily in the reduced tree).
     /// Any nodes which are not a descendant of `new_root` will be removed from the store.
     pub fn update_root(&mut self, new_slot: Slot, new_root: Hash256) -> Result<()> {
-        if !self.nodes.contains_key(&new_root) {
-            let node = Node {
-                block_hash: new_root,
-                voters: vec![],
-                ..Node::default()
-            };
-
-            self.add_node(node)?;
-        }
+        self.maybe_add_weightless_node(new_slot, new_root)?;
 
         self.retain_subtree(self.root.0, new_root)?;
 
@@ -247,7 +233,7 @@ where
         //
         // In this case, we add a weightless node at `start_block_root`.
         if !self.nodes.contains_key(&start_block_root) {
-            self.add_weightless_node(start_block_slot, start_block_root)?;
+            self.maybe_add_weightless_node(start_block_slot, start_block_root)?;
         };
 
         let _root_weight = self.update_weight(start_block_root, weight_fn)?;
@@ -325,51 +311,53 @@ where
     /// become redundant and removed from the reduced tree.
     fn remove_latest_message(&mut self, validator_index: usize) -> Result<()> {
         if let Some(vote) = *self.latest_votes.get(validator_index) {
-            self.get_mut_node(vote.hash)?.remove_voter(validator_index);
-            let node = self.get_node(vote.hash)?.clone();
+            if self.nodes.contains_key(&vote.hash) {
+                self.get_mut_node(vote.hash)?.remove_voter(validator_index);
+                let node = self.get_node(vote.hash)?.clone();
 
-            if let Some(parent_hash) = node.parent_hash {
-                if node.has_votes() || node.children.len() > 1 {
-                    // A node with votes or more than one child is never removed.
-                } else if node.children.len() == 1 {
-                    // A node which has only one child may be removed.
-                    //
-                    // Load the child of the node and set it's parent to be the parent of this
-                    // node (viz., graft the node's child to the node's parent)
-                    let child = self.get_mut_node(node.children[0])?;
-                    child.parent_hash = node.parent_hash;
+                if let Some(parent_hash) = node.parent_hash {
+                    if node.has_votes() || node.children.len() > 1 {
+                        // A node with votes or more than one child is never removed.
+                    } else if node.children.len() == 1 {
+                        // A node which has only one child may be removed.
+                        //
+                        // Load the child of the node and set it's parent to be the parent of this
+                        // node (viz., graft the node's child to the node's parent)
+                        let child = self.get_mut_node(node.children[0])?;
+                        child.parent_hash = node.parent_hash;
 
-                    // Graft the parent of this node to it's child.
-                    if let Some(parent_hash) = node.parent_hash {
-                        let parent = self.get_mut_node(parent_hash)?;
-                        parent.replace_child(node.block_hash, node.children[0])?;
+                        // Graft the parent of this node to it's child.
+                        if let Some(parent_hash) = node.parent_hash {
+                            let parent = self.get_mut_node(parent_hash)?;
+                            parent.replace_child(node.block_hash, node.children[0])?;
+                        }
+
+                        self.nodes.remove(&vote.hash);
+                    } else if node.children.is_empty() {
+                        // Remove the to-be-deleted node from it's parent.
+                        if let Some(parent_hash) = node.parent_hash {
+                            self.get_mut_node(parent_hash)?
+                                .remove_child(node.block_hash)?;
+                        }
+
+                        self.nodes.remove(&vote.hash);
+
+                        // A node which has no children may be deleted and potentially it's parent
+                        // too.
+                        self.maybe_delete_node(parent_hash)?;
+                    } else {
+                        // It is impossible for a node to have a number of children that is not 0, 1 or
+                        // greater than one.
+                        //
+                        // This code is strictly unnecessary, however we keep it for readability.
+                        unreachable!();
                     }
-
-                    self.nodes.remove(&vote.hash);
-                } else if node.children.is_empty() {
-                    // Remove the to-be-deleted node from it's parent.
-                    if let Some(parent_hash) = node.parent_hash {
-                        self.get_mut_node(parent_hash)?
-                            .remove_child(node.block_hash)?;
-                    }
-
-                    self.nodes.remove(&vote.hash);
-
-                    // A node which has no children may be deleted and potentially it's parent
-                    // too.
-                    self.maybe_delete_node(parent_hash)?;
                 } else {
-                    // It is impossible for a node to have a number of children that is not 0, 1 or
-                    // greater than one.
-                    //
-                    // This code is strictly unnecessary, however we keep it for readability.
-                    unreachable!();
+                    // A node without a parent is the genesis/finalized node and should never be removed.
                 }
-            } else {
-                // A node without a parent is the genesis/finalized node and should never be removed.
-            }
 
-            self.latest_votes.insert(validator_index, Some(vote));
+                self.latest_votes.insert(validator_index, Some(vote));
+            }
         }
 
         Ok(())
@@ -384,25 +372,30 @@ where
     /// - it does not have any votes.
     fn maybe_delete_node(&mut self, hash: Hash256) -> Result<()> {
         let should_delete = {
-            let node = self.get_node(hash)?.clone();
+            if let Ok(node) = self.get_node(hash) {
+                let node = node.clone();
 
-            if let Some(parent_hash) = node.parent_hash {
-                if (node.children.len() == 1) && !node.has_votes() {
-                    let child_hash = node.children[0];
+                if let Some(parent_hash) = node.parent_hash {
+                    if (node.children.len() == 1) && !node.has_votes() {
+                        let child_hash = node.children[0];
 
-                    // Graft the single descendant `node` to the `parent` of node.
-                    self.get_mut_node(child_hash)?.parent_hash = Some(parent_hash);
+                        // Graft the single descendant `node` to the `parent` of node.
+                        self.get_mut_node(child_hash)?.parent_hash = Some(parent_hash);
 
-                    // Detach `node` from `parent`, replacing it with `child`.
-                    self.get_mut_node(parent_hash)?
-                        .replace_child(hash, child_hash)?;
+                        // Detach `node` from `parent`, replacing it with `child`.
+                        self.get_mut_node(parent_hash)?
+                            .replace_child(hash, child_hash)?;
 
-                    true
+                        true
+                    } else {
+                        false
+                    }
                 } else {
+                    // A node without a parent is the genesis node and should not be deleted.
                     false
                 }
             } else {
-                // A node without a parent is the genesis node and should not be deleted.
+                // No need to delete a node that does not exist.
                 false
             }
         };
@@ -430,7 +423,7 @@ where
         Ok(())
     }
 
-    fn add_weightless_node(&mut self, slot: Slot, hash: Hash256) -> Result<()> {
+    fn maybe_add_weightless_node(&mut self, slot: Slot, hash: Hash256) -> Result<()> {
         if slot > self.root_slot() && !self.nodes.contains_key(&hash) {
             let node = Node {
                 block_hash: hash,
@@ -477,6 +470,7 @@ where
                 // descendant of both `node` and `prev_in_tree`.
                 if self
                     .iter_ancestors(child_hash)?
+                    .take_while(|(_, slot)| *slot >= self.root_slot())
                     .any(|(ancestor, _slot)| ancestor == node.block_hash)
                 {
                     let child = self.get_mut_node(child_hash)?;
@@ -562,6 +556,7 @@ where
     fn find_prev_in_tree(&mut self, hash: Hash256) -> Option<Hash256> {
         self.iter_ancestors(hash)
             .ok()?
+            .take_while(|(_, slot)| *slot >= self.root_slot())
             .find(|(root, _slot)| self.nodes.contains_key(root))
             .and_then(|(root, _slot)| Some(root))
     }
@@ -569,8 +564,12 @@ where
     /// For the two given block roots (`a_root` and `b_root`), find the first block they share in
     /// the tree. Viz, find the block that these two distinct blocks forked from.
     fn find_highest_common_ancestor(&self, a_root: Hash256, b_root: Hash256) -> Result<Hash256> {
-        let mut a_iter = self.iter_ancestors(a_root)?;
-        let mut b_iter = self.iter_ancestors(b_root)?;
+        let mut a_iter = self
+            .iter_ancestors(a_root)?
+            .take_while(|(_, slot)| *slot >= self.root_slot());
+        let mut b_iter = self
+            .iter_ancestors(b_root)?
+            .take_while(|(_, slot)| *slot >= self.root_slot());
 
         // Combines the `next()` fns on the `a_iter` and `b_iter` and returns the roots of two
         // blocks at the same slot, or `None` if we have gone past genesis or the root of this tree.

eth2/lmd_ghost/tests/test.rs

@@ -4,7 +4,8 @@
 extern crate lazy_static;
 
 use beacon_chain::test_utils::{
-    AttestationStrategy, BeaconChainHarness as BaseBeaconChainHarness, BlockStrategy,
+    generate_deterministic_keypairs, AttestationStrategy,
+    BeaconChainHarness as BaseBeaconChainHarness, BlockStrategy,
 };
 use lmd_ghost::{LmdGhost, ThreadSafeReducedTree as BaseThreadSafeReducedTree};
 use rand::{prelude::*, rngs::StdRng};
@@ -51,7 +52,7 @@ struct ForkedHarness {
 impl ForkedHarness {
     /// A new standard instance of with constant parameters.
     pub fn new() -> Self {
-        let harness = BeaconChainHarness::new(VALIDATOR_COUNT);
+        let harness = BeaconChainHarness::new(generate_deterministic_keypairs(VALIDATOR_COUNT));
 
         // Move past the zero slot.
         harness.advance_slot();

eth2/operation_pool/src/lib.rs

@@ -16,9 +16,9 @@ use state_processing::per_block_processing::errors::{
 };
 use state_processing::per_block_processing::{
     get_slashable_indices_modular, verify_attestation_for_block_inclusion,
-    verify_attestation_for_state, verify_attester_slashing, verify_exit,
-    verify_exit_time_independent_only, verify_proposer_slashing, verify_transfer,
-    verify_transfer_time_independent_only, VerifySignatures,
+    verify_attester_slashing, verify_exit, verify_exit_time_independent_only,
+    verify_proposer_slashing, verify_transfer, verify_transfer_time_independent_only,
+    VerifySignatures,
 };
 use std::collections::{btree_map::Entry, hash_map, BTreeMap, HashMap, HashSet};
 use std::marker::PhantomData;

eth2/state_processing/Cargo.toml

@@ -15,6 +15,7 @@ serde = "1.0"
 serde_derive = "1.0"
 lazy_static = "0.1"
 serde_yaml = "0.8"
+eth2_ssz = { path = "../utils/ssz" }
 beacon_chain = { path = "../../beacon_node/beacon_chain" }
 store = { path = "../../beacon_node/store" }
 lmd_ghost = { path = "../lmd_ghost" }

eth2/state_processing/benches/benches.rs

@@ -2,6 +2,7 @@ extern crate env_logger;
 
 use criterion::Criterion;
 use criterion::{black_box, criterion_group, criterion_main, Benchmark};
+use ssz::Encode;
 use state_processing::{test_utils::BlockBuilder, BlockSignatureStrategy, VerifySignatures};
 use types::{BeaconBlock, BeaconState, ChainSpec, EthSpec, MainnetEthSpec, MinimalEthSpec, Slot};
 
@@ -393,6 +394,32 @@ fn bench_block<T: EthSpec>(
         })
         .sample_size(10),
     );
+
+    let local_block = block.clone();
+    c.bench(
+        &title,
+        Benchmark::new("ssz_serialize_block", move |b| {
+            b.iter_batched_ref(
+                || (),
+                |_| black_box(local_block.as_ssz_bytes()),
+                criterion::BatchSize::SmallInput,
+            )
+        })
+        .sample_size(10),
+    );
+
+    let local_block = block.clone();
+    c.bench(
+        &title,
+        Benchmark::new("ssz_block_len", move |b| {
+            b.iter_batched_ref(
+                || (),
+                |_| black_box(local_block.ssz_bytes_len()),
+                criterion::BatchSize::SmallInput,
+            )
+        })
+        .sample_size(10),
+    );
 }
 
 criterion_group!(benches, all_benches,);

eth2/state_processing/src/common/get_attesting_indices.rs

@@ -17,11 +17,9 @@ pub fn get_attesting_indices<T: EthSpec>(
         target_relative_epoch,
     )?;
 
-    /* TODO(freeze): re-enable this?
-    if bitlist.len() > committee.committee.len() {
+    if bitlist.len() != committee.committee.len() {
         return Err(BeaconStateError::InvalidBitfield);
     }
-    */
 
     Ok(committee
         .committee

eth2/state_processing/src/common/get_compact_committees_root.rs

@@ -3,7 +3,7 @@ use types::*;
 
 /// Return the compact committee root at `relative_epoch`.
 ///
-/// Spec v0.8.0
+/// Spec v0.8.3
 pub fn get_compact_committees_root<T: EthSpec>(
     state: &BeaconState<T>,
     relative_epoch: RelativeEpoch,
@@ -11,28 +11,13 @@ pub fn get_compact_committees_root<T: EthSpec>(
 ) -> Result<Hash256, BeaconStateError> {
     let mut committees =
         FixedVector::<_, T::ShardCount>::from_elem(CompactCommittee::<T>::default());
-    // FIXME: this is a spec bug, whereby the start shard for the epoch after the next epoch
-    // is mistakenly used. The start shard from the cache SHOULD work.
-    // Waiting on a release to fix https://github.com/ethereum/eth2.0-specs/issues/1315
-    let start_shard = if relative_epoch == RelativeEpoch::Next {
-        state.next_epoch_start_shard(spec)?
-    } else {
-        state.get_epoch_start_shard(relative_epoch)?
-    };
+    let start_shard = state.get_epoch_start_shard(relative_epoch)?;
 
     for committee_number in 0..state.get_committee_count(relative_epoch)? {
         let shard = (start_shard + committee_number) % T::ShardCount::to_u64();
-        // FIXME: this is a partial workaround for the above, but it only works in the case
-        // where there's a committee for every shard in every epoch. It works for the minimal
-        // tests but not the mainnet ones.
-        let fake_shard = if relative_epoch == RelativeEpoch::Next {
-            (shard + 1) % T::ShardCount::to_u64()
-        } else {
-            shard
-        };
 
         for &index in state
-            .get_crosslink_committee_for_shard(fake_shard, relative_epoch)?
+            .get_crosslink_committee_for_shard(shard, relative_epoch)?
             .committee
         {
             let validator = state

eth2/state_processing/src/common/get_indexed_attestation.rs

@@ -11,6 +11,8 @@ pub fn get_indexed_attestation<T: EthSpec>(
     state: &BeaconState<T>,
     attestation: &Attestation<T>,
 ) -> Result<IndexedAttestation<T>> {
+    // Note: we rely on both calls to `get_attesting_indices` to check the bitfield lengths
+    // against the committee length
     let attesting_indices =
         get_attesting_indices(state, &attestation.data, &attestation.aggregation_bits)?;
 

eth2/state_processing/src/per_block_processing/signature_sets.rs

@@ -42,8 +42,12 @@ pub fn block_proposal_signature_set<'a, T: EthSpec>(
     block_signed_root: Option<Hash256>,
     spec: &'a ChainSpec,
 ) -> Result<SignatureSet<'a>> {
-    let block_proposer = &state.validators
-        [state.get_beacon_proposer_index(block.slot, RelativeEpoch::Current, spec)?];
+    let proposer_index =
+        state.get_beacon_proposer_index(block.slot, RelativeEpoch::Current, spec)?;
+    let block_proposer = &state
+        .validators
+        .get(proposer_index)
+        .ok_or_else(|| Error::ValidatorUnknown(proposer_index as u64))?;
 
     let domain = spec.get_domain(
         block.slot.epoch(T::slots_per_epoch()),

eth2/state_processing/src/per_block_processing/tests.rs

@@ -1,4 +1,5 @@
 #![cfg(all(test, not(feature = "fake_crypto")))]
+
 use super::block_processing_builder::BlockProcessingBuilder;
 use super::errors::*;
 use crate::{per_block_processing, BlockSignatureStrategy};

eth2/state_processing/src/per_epoch_processing.rs

@@ -1,8 +1,5 @@
 use crate::common::get_compact_committees_root;
-use apply_rewards::process_rewards_and_penalties;
 use errors::EpochProcessingError as Error;
-use process_slashings::process_slashings;
-use registry_updates::process_registry_updates;
 use std::collections::HashMap;
 use tree_hash::TreeHash;
 use types::*;
@@ -17,6 +14,10 @@ pub mod tests;
 pub mod validator_statuses;
 pub mod winning_root;
 
+pub use apply_rewards::process_rewards_and_penalties;
+pub use process_slashings::process_slashings;
+pub use registry_updates::process_registry_updates;
+
 /// Maps a shard to a winning root.
 ///
 /// It is generated during crosslink processing and later used to reward/penalize validators.
@@ -47,15 +48,10 @@ pub fn per_epoch_processing<T: EthSpec>(
     process_justification_and_finalization(state, &validator_statuses.total_balances)?;
 
     // Crosslinks.
-    let winning_root_for_shards = process_crosslinks(state, spec)?;
+    process_crosslinks(state, spec)?;
 
     // Rewards and Penalties.
-    process_rewards_and_penalties(
-        state,
-        &mut validator_statuses,
-        &winning_root_for_shards,
-        spec,
-    )?;
+    process_rewards_and_penalties(state, &mut validator_statuses, spec)?;
 
     // Registry Updates.
     process_registry_updates(state, spec)?;
@@ -159,9 +155,7 @@ pub fn process_justification_and_finalization<T: EthSpec>(
 pub fn process_crosslinks<T: EthSpec>(
     state: &mut BeaconState<T>,
     spec: &ChainSpec,
-) -> Result<WinningRootHashSet, Error> {
-    let mut winning_root_for_shards: WinningRootHashSet = HashMap::new();
-
+) -> Result<(), Error> {
     state.previous_crosslinks = state.current_crosslinks.clone();
 
     for &relative_epoch in &[RelativeEpoch::Previous, RelativeEpoch::Current] {
@@ -181,12 +175,11 @@ pub fn process_crosslinks<T: EthSpec>(
                 if 3 * winning_root.total_attesting_balance >= 2 * total_committee_balance {
                     state.current_crosslinks[shard as usize] = winning_root.crosslink.clone();
                 }
-                winning_root_for_shards.insert(shard, winning_root);
             }
         }
     }
 
-    Ok(winning_root_for_shards)
+    Ok(())
 }
 
 /// Finish up an epoch update.
@@ -218,45 +211,29 @@ pub fn process_final_updates<T: EthSpec>(
         }
     }
 
-    // Update start shard.
-    state.start_shard = state.next_epoch_start_shard(spec)?;
-
-    // This is a hack to allow us to update index roots and slashed balances for the next epoch.
-    //
-    // The indentation here is to make it obvious where the weird stuff happens.
-    {
-        state.slot += 1;
-
-        // Set active index root
-        let index_epoch = next_epoch + spec.activation_exit_delay;
-        let indices_list = VariableList::<usize, T::ValidatorRegistryLimit>::from(
-            state.get_active_validator_indices(index_epoch),
-        );
-        state.set_active_index_root(
-            index_epoch,
-            Hash256::from_slice(&indices_list.tree_hash_root()),
-            spec,
-        )?;
-
-        // Reset slashings
-        state.set_slashings(next_epoch, 0)?;
-
-        // Set randao mix
-        state.set_randao_mix(next_epoch, *state.get_randao_mix(current_epoch)?)?;
-
-        state.slot -= 1;
-    }
+    // Set active index root
+    let index_epoch = next_epoch + spec.activation_exit_delay;
+    let indices_list = VariableList::<usize, T::ValidatorRegistryLimit>::from(
+        state.get_active_validator_indices(index_epoch),
+    );
+    state.set_active_index_root(
+        index_epoch,
+        Hash256::from_slice(&indices_list.tree_hash_root()),
+        spec,
+    )?;
 
     // Set committees root
-    // Note: we do this out-of-order w.r.t. to the spec, because we don't want the slot to be
-    // incremented. It's safe because the updates to slashings and the RANDAO mix (above) don't
-    // affect this.
     state.set_compact_committee_root(
         next_epoch,
         get_compact_committees_root(state, RelativeEpoch::Next, spec)?,
-        spec,
     )?;
 
+    // Reset slashings
+    state.set_slashings(next_epoch, 0)?;
+
+    // Set randao mix
+    state.set_randao_mix(next_epoch, *state.get_randao_mix(current_epoch)?)?;
+
     // Set historical root accumulator
     if next_epoch.as_u64() % (T::SlotsPerHistoricalRoot::to_u64() / T::slots_per_epoch()) == 0 {
         let historical_batch = state.historical_batch();
@@ -265,6 +242,9 @@ pub fn process_final_updates<T: EthSpec>(
             .push(Hash256::from_slice(&historical_batch.tree_hash_root()))?;
     }
 
+    // Update start shard.
+    state.start_shard = state.get_epoch_start_shard(RelativeEpoch::Next)?;
+
     // Rotate current/previous epoch attestations
     state.previous_epoch_attestations =
         std::mem::replace(&mut state.current_epoch_attestations, VariableList::empty());

eth2/state_processing/src/per_epoch_processing/apply_rewards.rs

@@ -1,5 +1,5 @@
 use super::validator_statuses::{TotalBalances, ValidatorStatus, ValidatorStatuses};
-use super::{Error, WinningRootHashSet};
+use super::Error;
 use integer_sqrt::IntegerSquareRoot;
 use types::*;
 
@@ -36,7 +36,6 @@ impl std::ops::AddAssign for Delta {
 pub fn process_rewards_and_penalties<T: EthSpec>(
     state: &mut BeaconState<T>,
     validator_statuses: &mut ValidatorStatuses,
-    winning_root_for_shards: &WinningRootHashSet,
     spec: &ChainSpec,
 ) -> Result<(), Error> {
     if state.current_epoch() == T::genesis_epoch() {
@@ -53,15 +52,13 @@ pub fn process_rewards_and_penalties<T: EthSpec>(
     let mut deltas = vec![Delta::default(); state.balances.len()];
 
     get_attestation_deltas(&mut deltas, state, &validator_statuses, spec)?;
+
+    // Update statuses with the information from winning roots.
+    validator_statuses.process_winning_roots(state, spec)?;
+
     get_crosslink_deltas(&mut deltas, state, &validator_statuses, spec)?;
 
-    get_proposer_deltas(
-        &mut deltas,
-        state,
-        validator_statuses,
-        winning_root_for_shards,
-        spec,
-    )?;
+    get_proposer_deltas(&mut deltas, state, validator_statuses, spec)?;
 
     // Apply the deltas, over-flowing but not under-flowing (saturating at 0 instead).
     for (i, delta) in deltas.iter().enumerate() {
@@ -79,12 +76,8 @@ fn get_proposer_deltas<T: EthSpec>(
     deltas: &mut Vec<Delta>,
     state: &BeaconState<T>,
     validator_statuses: &mut ValidatorStatuses,
-    winning_root_for_shards: &WinningRootHashSet,
     spec: &ChainSpec,
 ) -> Result<(), Error> {
-    // Update statuses with the information from winning roots.
-    validator_statuses.process_winning_roots(state, winning_root_for_shards, spec)?;
-
     for (index, validator) in validator_statuses.statuses.iter().enumerate() {
         if validator.is_previous_epoch_attester {
             let inclusion = validator

eth2/state_processing/src/per_epoch_processing/validator_statuses.rs

@@ -1,4 +1,4 @@
-use super::WinningRootHashSet;
+use super::{winning_root::winning_root, WinningRootHashSet};
 use crate::common::get_attesting_indices;
 use types::*;
 
@@ -292,9 +292,29 @@ impl ValidatorStatuses {
     pub fn process_winning_roots<T: EthSpec>(
         &mut self,
         state: &BeaconState<T>,
-        winning_roots: &WinningRootHashSet,
         spec: &ChainSpec,
     ) -> Result<(), BeaconStateError> {
+        // We must re-calculate the winning roots here because it is possible that they have
+        // changed since the first time they were calculated.
+        //
+        // This is because we altered the state during the first time we calculated the winning
+        // roots.
+        let winning_root_for_shards = {
+            let mut winning_root_for_shards = WinningRootHashSet::new();
+            let relative_epoch = RelativeEpoch::Previous;
+
+            let epoch = relative_epoch.into_epoch(state.current_epoch());
+            for offset in 0..state.get_committee_count(relative_epoch)? {
+                let shard = (state.get_epoch_start_shard(relative_epoch)? + offset)
+                    % T::ShardCount::to_u64();
+                if let Some(winning_root) = winning_root(state, shard, epoch, spec)? {
+                    winning_root_for_shards.insert(shard, winning_root);
+                }
+            }
+
+            winning_root_for_shards
+        };
+
         // Loop through each slot in the previous epoch.
         for slot in state.previous_epoch().slot_iter(T::slots_per_epoch()) {
             let crosslink_committees_at_slot = state.get_crosslink_committees_at_slot(slot)?;
@@ -302,7 +322,7 @@ impl ValidatorStatuses {
             // Loop through each committee in the slot.
             for c in crosslink_committees_at_slot {
                 // If there was some winning crosslink root for the committee's shard.
-                if let Some(winning_root) = winning_roots.get(&c.shard) {
+                if let Some(winning_root) = winning_root_for_shards.get(&c.shard) {
                     let total_committee_balance = state.get_total_balance(&c.committee, spec)?;
                     for &validator_index in &winning_root.attesting_validator_indices {
                         // Take note of the balance information for the winning root, it will be

eth2/state_processing/src/per_epoch_processing/winning_root.rs

@@ -3,7 +3,7 @@ use std::collections::{HashMap, HashSet};
 use tree_hash::TreeHash;
 use types::*;
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct WinningRoot {
     pub crosslink: Crosslink,
     pub attesting_validator_indices: Vec<usize>,

eth2/state_processing/tests/tests.rs

@@ -1,3 +1,5 @@
+#![cfg(not(feature = "fake_crypto"))]
+
 use state_processing::{
     per_block_processing, test_utils::BlockBuilder, BlockProcessingError, BlockSignatureStrategy,
 };

eth2/types/Cargo.toml

@@ -31,3 +31,4 @@ tree_hash_derive = "0.2"
 
 [dev-dependencies]
 env_logger = "0.6.0"
+serde_json = "^1.0"

eth2/types/src/attestation_data.rs

@@ -4,25 +4,13 @@ use crate::{Checkpoint, Crosslink, Hash256};
 use serde_derive::{Deserialize, Serialize};
 use ssz_derive::{Decode, Encode};
 use test_random_derive::TestRandom;
-use tree_hash::TreeHash;
-use tree_hash_derive::{SignedRoot, TreeHash};
+use tree_hash_derive::TreeHash;
 
 /// The data upon which an attestation is based.
 ///
 /// Spec v0.8.0
 #[derive(
-    Debug,
-    Clone,
-    PartialEq,
-    Eq,
-    Serialize,
-    Deserialize,
-    Hash,
-    Encode,
-    Decode,
-    TreeHash,
-    TestRandom,
-    SignedRoot,
+    Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Hash, Encode, Decode, TreeHash, TestRandom,
 )]
 pub struct AttestationData {
     // LMD GHOST vote

eth2/types/src/beacon_state.rs

@@ -60,6 +60,22 @@ pub enum Error {
     SszTypesError(ssz_types::Error),
 }
 
+/// Control whether an epoch-indexed field can be indexed at the next epoch or not.
+#[derive(Debug, PartialEq, Clone, Copy)]
+enum AllowNextEpoch {
+    True,
+    False,
+}
+
+impl AllowNextEpoch {
+    fn upper_bound_of(self, current_epoch: Epoch) -> Epoch {
+        match self {
+            AllowNextEpoch::True => current_epoch + 1,
+            AllowNextEpoch::False => current_epoch,
+        }
+    }
+}
+
 /// The state of the `BeaconChain` at some slot.
 ///
 /// Spec v0.8.0
@@ -108,12 +124,12 @@ where
     pub start_shard: u64,
     pub randao_mixes: FixedVector<Hash256, T::EpochsPerHistoricalVector>,
     #[compare_fields(as_slice)]
-    active_index_roots: FixedVector<Hash256, T::EpochsPerHistoricalVector>,
+    pub active_index_roots: FixedVector<Hash256, T::EpochsPerHistoricalVector>,
     #[compare_fields(as_slice)]
-    compact_committees_roots: FixedVector<Hash256, T::EpochsPerHistoricalVector>,
+    pub compact_committees_roots: FixedVector<Hash256, T::EpochsPerHistoricalVector>,
 
     // Slashings
-    slashings: FixedVector<u64, T::EpochsPerSlashingsVector>,
+    pub slashings: FixedVector<u64, T::EpochsPerSlashingsVector>,
 
     // Attestations
     pub previous_epoch_attestations: VariableList<PendingAttestation<T>, T::MaxPendingAttestations>,
@@ -282,14 +298,6 @@ impl<T: EthSpec> BeaconState<T> {
         Ok(cache.epoch_start_shard())
     }
 
-    pub fn next_epoch_start_shard(&self, spec: &ChainSpec) -> Result<u64, Error> {
-        let cache = self.cache(RelativeEpoch::Current)?;
-        let active_validator_count = cache.active_validator_count();
-        let shard_delta = T::get_shard_delta(active_validator_count, spec.target_committee_size);
-
-        Ok((self.start_shard + shard_delta) % T::ShardCount::to_u64())
-    }
-
     /// Get the slot of an attestation.
     ///
     /// Note: Utilizes the cache and will fail if the appropriate cache is not initialized.
@@ -463,12 +471,16 @@ impl<T: EthSpec> BeaconState<T> {
 
     /// Safely obtains the index for `randao_mixes`
     ///
-    /// Spec v0.8.0
-    fn get_randao_mix_index(&self, epoch: Epoch) -> Result<usize, Error> {
+    /// Spec v0.8.1
+    fn get_randao_mix_index(
+        &self,
+        epoch: Epoch,
+        allow_next_epoch: AllowNextEpoch,
+    ) -> Result<usize, Error> {
         let current_epoch = self.current_epoch();
         let len = T::EpochsPerHistoricalVector::to_u64();
 
-        if epoch + len > current_epoch && epoch <= current_epoch {
+        if current_epoch < epoch + len && epoch <= allow_next_epoch.upper_bound_of(current_epoch) {
             Ok(epoch.as_usize() % len as usize)
         } else {
             Err(Error::EpochOutOfBounds)
@@ -496,7 +508,7 @@ impl<T: EthSpec> BeaconState<T> {
     ///
     /// Spec v0.8.1
     pub fn get_randao_mix(&self, epoch: Epoch) -> Result<&Hash256, Error> {
-        let i = self.get_randao_mix_index(epoch)?;
+        let i = self.get_randao_mix_index(epoch, AllowNextEpoch::False)?;
         Ok(&self.randao_mixes[i])
     }
 
@@ -504,21 +516,29 @@ impl<T: EthSpec> BeaconState<T> {
     ///
     /// Spec v0.8.1
     pub fn set_randao_mix(&mut self, epoch: Epoch, mix: Hash256) -> Result<(), Error> {
-        let i = self.get_randao_mix_index(epoch)?;
+        let i = self.get_randao_mix_index(epoch, AllowNextEpoch::True)?;
         self.randao_mixes[i] = mix;
         Ok(())
     }
 
     /// Safely obtains the index for `active_index_roots`, given some `epoch`.
     ///
+    /// If `allow_next_epoch` is `True`, then we allow an _extra_ one epoch of lookahead.
+    ///
     /// Spec v0.8.1
-    fn get_active_index_root_index(&self, epoch: Epoch, spec: &ChainSpec) -> Result<usize, Error> {
+    fn get_active_index_root_index(
+        &self,
+        epoch: Epoch,
+        spec: &ChainSpec,
+        allow_next_epoch: AllowNextEpoch,
+    ) -> Result<usize, Error> {
         let current_epoch = self.current_epoch();
 
         let lookahead = spec.activation_exit_delay;
         let lookback = self.active_index_roots.len() as u64 - lookahead;
+        let epoch_upper_bound = allow_next_epoch.upper_bound_of(current_epoch) + lookahead;
 
-        if epoch + lookback > current_epoch && current_epoch + lookahead >= epoch {
+        if current_epoch < epoch + lookback && epoch <= epoch_upper_bound {
             Ok(epoch.as_usize() % self.active_index_roots.len())
         } else {
             Err(Error::EpochOutOfBounds)
@@ -529,7 +549,7 @@ impl<T: EthSpec> BeaconState<T> {
     ///
     /// Spec v0.8.1
     pub fn get_active_index_root(&self, epoch: Epoch, spec: &ChainSpec) -> Result<Hash256, Error> {
-        let i = self.get_active_index_root_index(epoch, spec)?;
+        let i = self.get_active_index_root_index(epoch, spec, AllowNextEpoch::False)?;
         Ok(self.active_index_roots[i])
     }
 
@@ -542,7 +562,7 @@ impl<T: EthSpec> BeaconState<T> {
         index_root: Hash256,
         spec: &ChainSpec,
     ) -> Result<(), Error> {
-        let i = self.get_active_index_root_index(epoch, spec)?;
+        let i = self.get_active_index_root_index(epoch, spec, AllowNextEpoch::True)?;
         self.active_index_roots[i] = index_root;
         Ok(())
     }
@@ -556,19 +576,17 @@ impl<T: EthSpec> BeaconState<T> {
 
     /// Safely obtains the index for `compact_committees_roots`, given some `epoch`.
     ///
-    /// Spec v0.8.0
+    /// Spec v0.8.1
     fn get_compact_committee_root_index(
         &self,
         epoch: Epoch,
-        spec: &ChainSpec,
+        allow_next_epoch: AllowNextEpoch,
     ) -> Result<usize, Error> {
         let current_epoch = self.current_epoch();
+        let len = T::EpochsPerHistoricalVector::to_u64();
 
-        let lookahead = spec.activation_exit_delay;
-        let lookback = self.compact_committees_roots.len() as u64 - lookahead;
-
-        if epoch + lookback > current_epoch && current_epoch + lookahead >= epoch {
-            Ok(epoch.as_usize() % self.compact_committees_roots.len())
+        if current_epoch < epoch + len && epoch <= allow_next_epoch.upper_bound_of(current_epoch) {
+            Ok(epoch.as_usize() % len as usize)
         } else {
             Err(Error::EpochOutOfBounds)
         }
@@ -576,26 +594,21 @@ impl<T: EthSpec> BeaconState<T> {
 
     /// Return the `compact_committee_root` at a recent `epoch`.
     ///
-    /// Spec v0.8.0
-    pub fn get_compact_committee_root(
-        &self,
-        epoch: Epoch,
-        spec: &ChainSpec,
-    ) -> Result<Hash256, Error> {
-        let i = self.get_compact_committee_root_index(epoch, spec)?;
+    /// Spec v0.8.1
+    pub fn get_compact_committee_root(&self, epoch: Epoch) -> Result<Hash256, Error> {
+        let i = self.get_compact_committee_root_index(epoch, AllowNextEpoch::False)?;
         Ok(self.compact_committees_roots[i])
     }
 
     /// Set the `compact_committee_root` at a recent `epoch`.
     ///
-    /// Spec v0.8.0
+    /// Spec v0.8.1
     pub fn set_compact_committee_root(
         &mut self,
         epoch: Epoch,
         index_root: Hash256,
-        spec: &ChainSpec,
     ) -> Result<(), Error> {
-        let i = self.get_compact_committee_root_index(epoch, spec)?;
+        let i = self.get_compact_committee_root_index(epoch, AllowNextEpoch::True)?;
         self.compact_committees_roots[i] = index_root;
         Ok(())
     }
@@ -646,14 +659,19 @@ impl<T: EthSpec> BeaconState<T> {
 
     /// Safely obtain the index for `slashings`, given some `epoch`.
     ///
-    /// Spec v0.8.0
-    fn get_slashings_index(&self, epoch: Epoch) -> Result<usize, Error> {
+    /// Spec v0.8.1
+    fn get_slashings_index(
+        &self,
+        epoch: Epoch,
+        allow_next_epoch: AllowNextEpoch,
+    ) -> Result<usize, Error> {
         // We allow the slashings vector to be accessed at any cached epoch at or before
-        // the current epoch.
-        if epoch <= self.current_epoch()
-            && epoch + T::EpochsPerSlashingsVector::to_u64() >= self.current_epoch() + 1
+        // the current epoch, or the next epoch if `AllowNextEpoch::True` is passed.
+        let current_epoch = self.current_epoch();
+        if current_epoch < epoch + T::EpochsPerSlashingsVector::to_u64()
+            && epoch <= allow_next_epoch.upper_bound_of(current_epoch)
         {
-            Ok((epoch.as_u64() % T::EpochsPerSlashingsVector::to_u64()) as usize)
+            Ok(epoch.as_usize() % T::EpochsPerSlashingsVector::to_usize())
         } else {
             Err(Error::EpochOutOfBounds)
         }
@@ -668,17 +686,17 @@ impl<T: EthSpec> BeaconState<T> {
 
     /// Get the total slashed balances for some epoch.
     ///
-    /// Spec v0.8.0
+    /// Spec v0.8.1
     pub fn get_slashings(&self, epoch: Epoch) -> Result<u64, Error> {
-        let i = self.get_slashings_index(epoch)?;
+        let i = self.get_slashings_index(epoch, AllowNextEpoch::False)?;
         Ok(self.slashings[i])
     }
 
     /// Set the total slashed balances for some epoch.
     ///
-    /// Spec v0.8.0
+    /// Spec v0.8.1
     pub fn set_slashings(&mut self, epoch: Epoch, value: u64) -> Result<(), Error> {
-        let i = self.get_slashings_index(epoch)?;
+        let i = self.get_slashings_index(epoch, AllowNextEpoch::True)?;
         self.slashings[i] = value;
         Ok(())
     }

eth2/types/src/beacon_state/beacon_state_types.rs

@@ -120,6 +120,13 @@ pub trait EthSpec: 'static + Default + Sync + Send + Clone + Debug + PartialEq {
     fn epochs_per_historical_vector() -> usize {
         Self::EpochsPerHistoricalVector::to_usize()
     }
+
+    /// Returns the `SLOTS_PER_ETH1_VOTING_PERIOD` constant for this specification.
+    ///
+    /// Spec v0.8.1
+    fn slots_per_eth1_voting_period() -> usize {
+        Self::EpochsPerHistoricalVector::to_usize()
+    }
 }
 
 /// Macro to inherit some type values from another EthSpec.

eth2/types/src/beacon_state/committee_cache/tests.rs

@@ -9,7 +9,7 @@ fn default_values() {
     let cache = CommitteeCache::default();
 
     assert_eq!(cache.is_initialized_at(Epoch::new(0)), false);
-    assert_eq!(cache.active_validator_indices(), &[]);
+    assert!(&cache.active_validator_indices().is_empty());
     assert_eq!(cache.get_crosslink_committee_for_shard(0), None);
     assert_eq!(cache.get_attestation_duties(0), None);
     assert_eq!(cache.active_validator_count(), 0);

eth2/types/src/beacon_state/tests.rs

@@ -90,11 +90,11 @@ fn test_active_index<T: EthSpec>(state_slot: Slot) {
 
     // Test the start and end of the range.
     assert_eq!(
-        state.get_active_index_root_index(*range.start(), &spec),
+        state.get_active_index_root_index(*range.start(), &spec, AllowNextEpoch::False),
         Ok(modulo(*range.start()))
     );
     assert_eq!(
-        state.get_active_index_root_index(*range.end(), &spec),
+        state.get_active_index_root_index(*range.end(), &spec, AllowNextEpoch::False),
         Ok(modulo(*range.end()))
     );
 
@@ -102,12 +102,12 @@ fn test_active_index<T: EthSpec>(state_slot: Slot) {
     if state.current_epoch() > 0 {
         // Test is invalid on epoch zero, cannot subtract from zero.
         assert_eq!(
-            state.get_active_index_root_index(*range.start() - 1, &spec),
+            state.get_active_index_root_index(*range.start() - 1, &spec, AllowNextEpoch::False),
             Err(Error::EpochOutOfBounds)
         );
     }
     assert_eq!(
-        state.get_active_index_root_index(*range.end() + 1, &spec),
+        state.get_active_index_root_index(*range.end() + 1, &spec, AllowNextEpoch::False),
         Err(Error::EpochOutOfBounds)
     );
 }

eth2/types/src/chain_spec.rs

@@ -58,7 +58,7 @@ pub struct ChainSpec {
     /*
      * Time parameters
      */
-    pub seconds_per_slot: u64,
+    pub milliseconds_per_slot: u64,
     pub min_attestation_inclusion_delay: u64,
     pub min_seed_lookahead: Epoch,
     pub activation_exit_delay: u64,
@@ -158,7 +158,7 @@ impl ChainSpec {
             /*
              * Time parameters
              */
-            seconds_per_slot: 6,
+            milliseconds_per_slot: 6_000,
             min_attestation_inclusion_delay: 1,
             min_seed_lookahead: Epoch::new(1),
             activation_exit_delay: 4,
@@ -221,7 +221,7 @@ impl ChainSpec {
         let boot_nodes = vec![];
 
         Self {
-            seconds_per_slot: 12,
+            milliseconds_per_slot: 12_000,
             target_committee_size: 4,
             shuffle_round_count: 10,
             network_id: 13,

eth2/types/src/checkpoint.rs

@@ -3,8 +3,7 @@ use crate::{Epoch, Hash256};
 use serde_derive::{Deserialize, Serialize};
 use ssz_derive::{Decode, Encode};
 use test_random_derive::TestRandom;
-use tree_hash::TreeHash;
-use tree_hash_derive::{SignedRoot, TreeHash};
+use tree_hash_derive::TreeHash;
 
 /// Casper FFG checkpoint, used in attestations.
 ///
@@ -22,7 +21,6 @@ use tree_hash_derive::{SignedRoot, TreeHash};
     Decode,
     TreeHash,
     TestRandom,
-    SignedRoot,
 )]
 pub struct Checkpoint {
     pub epoch: Epoch,