Cross-compile to vendored x86_84, aarch64 (Raspberry Pi 4) (#1497)

## Issue Addressed

NA

## Proposed Changes

Adds support for using the [`cross`](https://github.com/rust-embedded/cross) project to produce cross-compiled binaries using Docker images.

Provides quite clean and simple cross-compiles cause all the complexity is hidden in Dockerfiles. It does require you to be in the `docker` group though.

## Details

- Adds shortcut commands to `Makefile`
- Ensures `reqwest` and `discv5` use vendored openssl libs (i.e., static not shared).
- Switches to a [commit](284f705964) of blst that has a renamed C function to avoid a collision with openssl (upstream issue: https://github.com/supranational/blst/issues/21).
- Updates `ring` to the latest satisfiable version, since an earlier version was causing issues with `cross`.
- Off-topic, but adds extra message about Windows support as suggested by Discord user.

## Additional Info

- ~~Blocked on #1495~~
- There are no tests in CI for this yet for a few reasons:
  - I'm hesitant to add more long-running tasks.
  - Short-term bitrot should be avoided since we'll use it each release.
  - In the long term I think it would be good to automate binary creation on a release.
- I observed the binaries increase in size from 50mb to 52mb after these changes.

Cargo.lock

@@ -521,7 +521,7 @@ dependencies = [
 [[package]]
 name = "blst"
 version = "0.1.1"
-source = "git+https://github.com/sigp/blst.git?rev=22bfb91721af125d1cb08aa201a18477665a45fe#22bfb91721af125d1cb08aa201a18477665a45fe"
+source = "git+https://github.com/sigp/blst.git?rev=284f7059642851c760a09fb1708bcb59c7ca323c#284f7059642851c760a09fb1708bcb59c7ca323c"
 dependencies = [
  "cc",
  "glob",
@@ -3468,6 +3468,15 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "77af24da69f9d9341038eba93a073b1fdaaa1b788221b00a69bce9e762cb32de"
 
+[[package]]
+name = "openssl-src"
+version = "111.10.2+1.1.1g"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a287fdb22e32b5b60624d4a5a7a02dbe82777f730ec0dbc42a0554326fef5a70"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "openssl-sys"
 version = "0.9.58"
@@ -3477,6 +3486,7 @@ dependencies = [
  "autocfg 1.0.0",
  "cc",
  "libc",
+ "openssl-src",
  "pkg-config",
  "vcpkg",
 ]

Makefile

@@ -21,6 +21,28 @@ else
 	cargo install --path lcli --force --locked
 endif
 
+# The following commands use `cross` to build a cross-compile.
+#
+# These commands require that:
+#
+# - `cross` is installed (`cargo install cross`).
+# - Docker is running.
+# - The current user is in the `docker` group.
+#
+# The resulting binaries will be created in the `target/` directory.
+#
+# The *-portable options compile the blst library *without* the use of some
+# optimized CPU functions that may not be available on some systems. This
+# results in a more portable binary with ~20% slower BLS verification.
+build-x86_64:
+	cross build --release --manifest-path lighthouse/Cargo.toml --target x86_64-unknown-linux-gnu
+build-x86_64-portable:
+	cross build --release --manifest-path lighthouse/Cargo.toml --target x86_64-unknown-linux-gnu --features portable
+build-aarch64:
+	cross build --release --manifest-path lighthouse/Cargo.toml --target aarch64-unknown-linux-gnu
+build-aarch64-portable:
+	cross build --release --manifest-path lighthouse/Cargo.toml --target aarch64-unknown-linux-gnu --features portable
+
 # Runs the full workspace tests in **release**, without downloading any additional
 # test vectors.
 test-release:

beacon_node/client/Cargo.toml

@@ -31,7 +31,7 @@ slog-async = "2.5.0"
 tokio = "0.2.21"
 dirs = "2.0.2"
 futures = "0.3.5"
-reqwest = "0.10.4"
+reqwest = { version = "0.10.4", features = ["native-tls-vendored"] }
 url = "2.1.1"
 eth1 = { path = "../eth1" }
 genesis = { path = "../genesis" }

beacon_node/eth1/Cargo.toml

@@ -11,7 +11,7 @@ web3 = "0.11.0"
 sloggers = "1.0.0"
 
 [dependencies]
-reqwest = "0.10.4"
+reqwest = { version = "0.10.4", features = ["native-tls-vendored"] }
 futures = { version = "0.3.5", features = ["compat"] }
 serde_json = "1.0.52"
 serde = { version = "1.0.110", features = ["derive"] }

beacon_node/eth2_libp2p/Cargo.toml

@@ -32,7 +32,7 @@ snap = "1.0.0"
 void = "1.0.2"
 tokio-io-timeout = "0.4.0"
 tokio-util = { version = "0.3.1", features = ["codec", "compat"] }
-discv5 = { version = "0.1.0-alpha.8", features = ["libp2p"] }
+discv5 = { version = "0.1.0-alpha.8", features = ["libp2p", "openssl-vendored"] }
 tiny-keccak = "2.0.2"
 environment = { path = "../../lighthouse/environment" }
 # TODO: Remove rand crate for mainnet

book/src/SUMMARY.md

@@ -7,6 +7,7 @@
 * [Installation](./installation.md)
     * [Docker](./docker.md)
     * [Raspberry Pi 4](./pi.md)
+    * [Cross-Compiling](./cross-compiling.md)
 * [Key Management](./key-management.md)
     * [Create a wallet](./wallet-create.md)
     * [Create a validator](./validator-create.md)

book/src/become-a-validator-source.md

@@ -3,7 +3,9 @@
 ## 0. Install Rust
 If you don't have Rust installed already, visit [rustup.rs](https://rustup.rs/) to install it.
 
-> Note:  if you're not familiar with Rust or you'd like more detailed instructions, see our  [installation guide](./installation.md).
+> Notes:
+>   - If you're not familiar with Rust or you'd like more detailed instructions, see our  [installation guide](./installation.md).
+>   - Windows is presently only supported via [WSL](https://docs.microsoft.com/en-us/windows/wsl/about).
 
 
 ## 1. Download and install Lighthouse

book/src/cross-compiling.md

@@ -0,0 +1,41 @@
+# Cross-compiling
+
+Lighthouse supports cross-compiling, allowing users to run a binary on one
+platform (e.g., `aarch64`) that was compiled on another platform (e.g.,
+`x86_64`).
+
+
+## Instructions
+
+Cross-compiling requires [`Docker`](https://docs.docker.com/engine/install/),
+[`rustembedded/cross`](https://github.com/rust-embedded/cross) and for the
+current user to be in the `docker` group.
+
+The binaries will be created in the `target/` directory of the Lighthouse
+project.
+
+### Targets
+
+The `Makefile` in the project contains four targets for cross-compiling:
+
+- `build-x86_64`: builds an optimized version for x86_64 processors (suitable
+	for most users).
+- `build-x86_64-portable`: builds a version x86_64 processors which avoids
+	using some modern CPU instructions that might cause an "illegal
+	instruction" error on older CPUs.
+- `build-aarch64`: builds an optimized version for 64bit ARM processors
+	(suitable for Raspberry Pi 4).
+- `build-aarch64-portable`: builds a version 64 bit ARM processors which avoids
+	using some modern CPU instructions that might cause an "illegal
+	instruction" error on older CPUs.
+
+
+### Example
+
+```bash
+cd lighthouse
+make build-aarch64
+```
+
+The `lighthouse` binary will be compiled inside a Docker container and placed
+in `lighthouse/target/aarch64-unknown-linux-gnu/release`.

book/src/pi.md

@@ -5,6 +5,11 @@ Tested on:
  - Raspberry Pi 4 Model B (4GB)
  - `Ubuntu 20.04 LTS (GNU/Linux 5.4.0-1011-raspi aarch64)`
 
+
+*Note: [Lighthouse supports cross-compiling](./cross-compiling.md) to target a
+Raspberry Pi (`aarch64`). Compiling on a faster machine (i.e., `x86_64`
+desktop) may be convenient.*
+
 ### 1. Install Ubuntu
 
 Follow the [Ubuntu Raspberry Pi installation instructions](https://ubuntu.com/download/raspberry-pi).

common/deposit_contract/Cargo.toml

@@ -7,7 +7,7 @@ edition = "2018"
 build = "build.rs"
 
 [build-dependencies]
-reqwest = { version = "0.10.4", features = ["blocking", "json"] }
+reqwest = { version = "0.10.4", features = ["blocking", "json", "native-tls-vendored"] }
 serde_json = "1.0.52"
 sha2 = "0.9.1"
 hex = "0.4.2"

common/eth2_testnet_config/Cargo.toml

@@ -7,7 +7,7 @@ edition = "2018"
 build = "build.rs"
 
 [build-dependencies]
-reqwest = { version = "0.10.4", features = ["blocking"] }
+reqwest = { version = "0.10.4", features = ["blocking", "native-tls-vendored"] }
 eth2_config = { path = "../eth2_config"}
 handlebars = "3.3.0"
 serde_json = "1.0.56"

common/remote_beacon_node/Cargo.toml

@@ -7,7 +7,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-reqwest = { version = "0.10.4", features = ["json"] }
+reqwest = { version = "0.10.4", features = ["json", "native-tls-vendored"] }
 url = "2.1.1"
 serde = "1.0.110"
 futures = "0.3.5"

crypto/bls/Cargo.toml

@@ -17,7 +17,7 @@ eth2_hashing = "0.1.0"
 ethereum-types = "0.9.1"
 arbitrary = { version = "0.4.4", features = ["derive"], optional = true }
 zeroize = { version = "1.0.0", features = ["zeroize_derive"] }
-blst = { git = "https://github.com/sigp/blst.git", rev = "22bfb91721af125d1cb08aa201a18477665a45fe" }
+blst = { git = "https://github.com/sigp/blst.git", rev = "284f7059642851c760a09fb1708bcb59c7ca323c" }
 
 [features]
 default = ["supranational"]

crypto/eth2_hashing/Cargo.toml

@@ -10,7 +10,7 @@ description = "Hashing primitives used in Ethereum 2.0"
 lazy_static = { version = "1.4.0", optional = true }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
-ring = "0.16.9"
+ring = "0.16.12"
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 sha2 = "0.9.1"

lighthouse/environment/Cargo.toml

@@ -21,4 +21,4 @@ slog-json = "2.3.0"
 exit-future = "0.2.0"
 lazy_static = "1.4.0"
 lighthouse_metrics = { path = "../../common/lighthouse_metrics" }
-discv5 = "0.1.0-alpha.8"
+discv5 = { version = "0.1.0-alpha.8", features = ["libp2p", "openssl-vendored"] }

testing/node_test_rig/Cargo.toml

@@ -10,7 +10,7 @@ beacon_node = { path = "../../beacon_node" }
 types = { path = "../../consensus/types" }
 eth2_config = { path = "../../common/eth2_config" }
 tempdir = "0.3.7"
-reqwest = "0.10.4"
+reqwest = { version = "0.10.4", features = ["native-tls-vendored"] }
 url = "2.1.1"
 serde = "1.0.110"
 futures = "0.3.5"