Adds error handling to validator client service

beacon_node/client/src/lib.rs

@@ -64,8 +64,6 @@ impl<TClientType: ClientTypes> Client<TClientType> {
             ));
         }
 
-        println!("Here");
-
         Ok(Client {
             config,
             beacon_chain,

validator_client/Cargo.toml

@@ -21,3 +21,4 @@ slog-term = "^2.4.0"
 slog-async = "^2.3.0"
 tokio = "0.1.18"
 tokio-timer = "0.2.10"
+error-chain = "0.12.0"

validator_client/src/error.rs

@@ -0,0 +1,22 @@
+use slot_clock;
+
+use error_chain::{
+    error_chain, error_chain_processing, impl_error_chain_kind, impl_error_chain_processed,
+    impl_extract_backtrace,
+};
+
+error_chain! {
+   links  { }
+
+   errors {
+    SlotClockError(e: slot_clock::SystemTimeSlotClockError) {
+        description("Error reading system time"),
+        display("SlotClockError: '{:?}'", e)
+    }
+
+    SystemTimeError(t: String ) {
+        description("Error reading system time"),
+        display("SystemTimeError: '{}'", t)
+    }
+   }
+}

validator_client/src/main.rs

@@ -2,12 +2,13 @@ mod attester_service;
 mod block_producer_service;
 mod config;
 mod duties;
+pub mod error;
 mod service;
 
 use crate::config::Config as ValidatorConfig;
 use clap::{App, Arg};
 use service::Service as ValidatorService;
-use slog::{o, Drain};
+use slog::{error, info, o, Drain};
 
 fn main() {
     // Logging
@@ -50,5 +51,8 @@ fn main() {
     let config = ValidatorConfig::parse_args(matches, &log).unwrap();
 
     // start the validator service.
-    ValidatorService::start(config, log);
+    match ValidatorService::start(config, log.clone()) {
+        Ok(_) => info!(log, "Validator client shutdown successfully."),
+        Err(e) => error!(log, "Validator exited due to {:?}", e),
+    }
 }

validator_client/src/service.rs

@@ -3,6 +3,8 @@ use crate::attester_service::{AttestationGrpcClient, AttesterService};
 use crate::block_producer_service::{BeaconBlockGrpcClient, BlockProducerService};
 use crate::config::Config as ValidatorConfig;
 use crate::duties::{DutiesManager, DutiesManagerService, EpochDutiesMap};
+use crate::error as error_chain;
+use crate::error::ErrorKind;
 use attester::test_utils::EpochMap;
 use attester::{test_utils::LocalSigner as AttesterLocalSigner, Attester};
 use block_proposer::{test_utils::LocalSigner as BlockProposerLocalSigner, BlockProducer};
@@ -13,9 +15,8 @@ use protos::services_grpc::{
     AttestationServiceClient, BeaconBlockServiceClient, BeaconNodeServiceClient,
     ValidatorServiceClient,
 };
-use slog::{debug, info, warn};
+use slog::{debug, error, info, warn};
 use slot_clock::{SlotClock, SystemTimeSlotClock};
-use std::ops::Sub;
 use std::sync::Arc;
 use std::time::{Duration, Instant, SystemTime};
 use tokio::prelude::*;
@@ -57,7 +58,10 @@ impl Service {
     ///
     ///  This tries to connect to a beacon node. Once connected, it initialised the gRPC clients
     ///  and returns an instance of the service.
-    fn initialize_service(config: &ValidatorConfig, log: slog::Logger) -> Self {
+    fn initialize_service(
+        config: &ValidatorConfig,
+        log: slog::Logger,
+    ) -> error_chain::Result<Self> {
         // initialise the beacon node client to check for a connection
 
         let env = Arc::new(EnvBuilder::new().build());
@@ -86,7 +90,7 @@ impl Service {
                             log,
                             "Beacon Node's genesis time is in the future. No work to do.\n Exiting"
                         );
-                        //                        return Err("Genesis Time in the future");
+                        return Err("Genesis time in the future".into());
                     }
                     break info;
                 }
@@ -136,35 +140,37 @@ impl Service {
             Arc::new(AttestationServiceClient::new(ch))
         };
 
-        //TODO: Add error chain. Handle errors
+        let current_slot = slot_clock
-        let current_slot = slot_clock.present_slot().unwrap().unwrap().sub(1);
+            .present_slot()
+            .map_err(|e| ErrorKind::SlotClockError(e))?
+            .expect("Genesis must be in the future");
 
         // calculate the duration to the next slot
         let duration_to_next_slot = {
+            let seconds_per_slot = config.spec.seconds_per_slot;
             let syslot_time = SystemTime::now();
-            let duration_since_epoch = syslot_time.duration_since(SystemTime::UNIX_EPOCH).unwrap();
+            let duration_since_epoch = syslot_time
-            let mut duration_to_next_slot = None;
+                .duration_since(SystemTime::UNIX_EPOCH)
-            if let Some(duration_since_genesis) =
+                .map_err(|e| ErrorKind::SystemTimeError(e.to_string()))?;
-                duration_since_epoch.checked_sub(Duration::from_secs(genesis_time))
+            let duration_since_genesis = duration_since_epoch
-            {
+                .checked_sub(Duration::from_secs(genesis_time))
-                let elapsed_slots = duration_since_epoch
+                .expect("Genesis must be in the future. Checked on connection");
-                    .as_secs()
+            let elapsed_slots = duration_since_epoch
-                    .checked_div(config.spec.seconds_per_slot as u64)
+                .as_secs()
-                    .unwrap();
+                .checked_div(seconds_per_slot as u64)
-                duration_to_next_slot = Some(
+                .expect("Seconds per slot should not be 0");
-                    Duration::from_secs(
+
-                        (elapsed_slots + 1)
+            // the duration to the next slot
-                            .checked_mul(config.spec.seconds_per_slot)
+            Duration::from_secs(
-                            .unwrap(),
+                (elapsed_slots + 1)
-                    )
+                    .checked_mul(seconds_per_slot)
-                    .checked_sub(duration_since_genesis)
+                    .expect("Next slot time should not overflow u64"),
-                    .expect("This should never saturate"),
+            )
-                );
+            .checked_sub(duration_since_genesis)
-            }
+            .expect("This should never saturate")
-            duration_to_next_slot.unwrap_or_else(|| Duration::from_secs(0))
         };
 
-        Self {
+        Ok(Self {
             connected_node_version: node_info.version,
             chain_id: node_info.chain_id as u16,
             fork,
@@ -175,13 +181,13 @@ impl Service {
             validator_client,
             attester_client,
             log,
-        }
+        })
     }
 
     /// Initialise the service then run the core thread.
-    pub fn start(config: ValidatorConfig, log: slog::Logger) {
+    pub fn start(config: ValidatorConfig, log: slog::Logger) -> error_chain::Result<()> {
         // connect to the node and retrieve its properties and initialize the gRPC clients
-        let service = Service::initialize_service(&config, log);
+        let service = Service::initialize_service(&config, log)?;
 
         // we have connected to a node and established its parameters. Spin up the core service
 
@@ -190,10 +196,9 @@ impl Service {
             .clock(Clock::system())
             .name_prefix("validator-client-")
             .build()
-            .unwrap();
+            .map_err(|e| format!("Tokio runtime failed: {}", e))?;
 
         // set up the validator work interval - start at next slot and proceed every slot
-        // TODO: Error chain handle errors.
         let interval = {
             // Set the interval to start at the next slot, and every slot after
             let slot_duration = Duration::from_secs(config.spec.seconds_per_slot);
@@ -223,16 +228,23 @@ impl Service {
             beacon_node: service.validator_client.clone(),
         };
 
-        runtime.block_on(interval.for_each(move |_| {
+        runtime
-            // update duties
+            .block_on(interval.for_each(move |_| {
-            debug!(
+                // update duties
-                service.log,
+                let current_slot = match service.slot_clock.present_slot() {
-                "Processing slot: {}",
+                    Err(e) => {
-                service.slot_clock.present_slot().unwrap().unwrap().as_u64()
+                        error!(service.log, "SystemTimeError {:?}", e);
-            );
+                        return Ok(());
-            manager.poll();
+                    }
-            Ok(())
+                    Ok(slot) => slot.expect("Genesis is in the future"),
-        }));
+                };
+
+                debug!(service.log, "Processing slot: {}", current_slot.as_u64());
+                manager.poll();
+                Ok(())
+            }))
+            .map_err(|e| format!("Service thread failed: {:?}", e))?;
+        Ok(())
     }
 
     /*