Add self-hosted runners v2 (#4506)

## Issue Addressed

NA

## Proposed Changes

Carries on from #4115, with the following modifications:

1. Self-hosted runners are only enabled if `github.repository == sigp/lighthouse`.
    - This allows forks to still have Github-hosted CI.
    - This gives us a method to switch back to Github-runners if we have extended downtime on self-hosted. 
1. Does not remove any existing dependency builds for Github-hosted runners (e.g., installing the latest Rust).
1. Adds the `WATCH_HOST` environment variable which defines where we expect to find the postgres db in the `watch` tests. This should be set to `host.docker.internal` for the tests to pass on self-hosted runners.

## Additional Info

NA


Co-authored-by: antondlr <anton@delaruelle.net>

.github/workflows/test-suite.yml

@@ -17,6 +17,10 @@ env:
   PINNED_NIGHTLY: nightly-2023-04-16
   # Prevent Github API rate limiting.
   LIGHTHOUSE_GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+  # Enable self-hosted runners for the sigp repo only.
+  SELF_HOSTED_RUNNERS: ${{ github.repository == 'sigp/lighthouse' }}
+  # Self-hosted runners need to reference a different host for `./watch` tests.
+  WATCH_HOST: ${{ github.repository == 'sigp/lighthouse' && 'host.docker.internal' || 'localhost' }}
 jobs:
   target-branch-check:
     name: target-branch-check
@@ -48,11 +52,13 @@ jobs:
       run: make cargo-fmt
   release-tests-ubuntu:
     name: release-tests-ubuntu
-    runs-on: ubuntu-latest
+    # Use self-hosted runners only on the sigp repo.
+    runs-on: ${{ github.repository == 'sigp/lighthouse' && fromJson('["self-hosted", "linux", "large"]') || 'ubuntu-latest'  }}
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v3
     - name: Get latest version of stable Rust
+      if: env.SELF_HOSTED_RUNNERS == false
       run: rustup update stable
     - name: Install Protoc
       uses: arduino/setup-protoc@e52d9eb8f7b63115df1ac544a1376fdbf5a39612
@@ -64,11 +70,12 @@ jobs:
       run: make test-release
   release-tests-windows:
     name: release-tests-windows
-    runs-on: windows-2019
+    runs-on: ${{ github.repository == 'sigp/lighthouse' && fromJson('["self-hosted", "windows"]') || 'windows-2019'  }}
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v3
     - name: Get latest version of stable Rust
+      if: env.SELF_HOSTED_RUNNERS == false
       run: rustup update stable
     - name: Use Node.js
       uses: actions/setup-node@v2
@@ -83,6 +90,7 @@ jobs:
     - name: Install make
       run: choco install -y make
     - uses: KyleMayes/install-llvm-action@v1
+      if: env.SELF_HOSTED_RUNNERS == false
       with:
         version: "15.0"
         directory: ${{ runner.temp }}/llvm
@@ -92,11 +100,13 @@ jobs:
       run: make test-release
   beacon-chain-tests:
     name: beacon-chain-tests
-    runs-on: ubuntu-latest
+    # Use self-hosted runners only on the sigp repo.
+    runs-on: ${{ github.repository == 'sigp/lighthouse' && fromJson('["self-hosted", "linux", "large"]') || 'ubuntu-latest'  }}
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v3
     - name: Get latest version of stable Rust
+      if: env.SELF_HOSTED_RUNNERS == false
       run: rustup update stable
     - name: Install Protoc
       uses: arduino/setup-protoc@e52d9eb8f7b63115df1ac544a1376fdbf5a39612
@@ -130,11 +140,13 @@ jobs:
       run: make test-slasher
   debug-tests-ubuntu:
     name: debug-tests-ubuntu
-    runs-on: ubuntu-22.04
+    # Use self-hosted runners only on the sigp repo.
+    runs-on: ${{ github.repository == 'sigp/lighthouse' && fromJson('["self-hosted", "linux", "large"]') || 'ubuntu-latest'  }}
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v3
     - name: Get latest version of stable Rust
+      if: env.SELF_HOSTED_RUNNERS == false
       run: rustup update stable
     - name: Install Protoc
       uses: arduino/setup-protoc@e52d9eb8f7b63115df1ac544a1376fdbf5a39612
@@ -160,11 +172,13 @@ jobs:
       run: make run-state-transition-tests
   ef-tests-ubuntu:
     name: ef-tests-ubuntu
-    runs-on: ubuntu-latest
+    # Use self-hosted runners only on the sigp repo.
+    runs-on: ${{ github.repository == 'sigp/lighthouse' && fromJson('["self-hosted", "linux", "small"]') || 'ubuntu-latest'  }}
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v3
     - name: Get latest version of stable Rust
+      if: env.SELF_HOSTED_RUNNERS == false
       run: rustup update stable
     - name: Install Protoc
       uses: arduino/setup-protoc@e52d9eb8f7b63115df1ac544a1376fdbf5a39612

watch/tests/tests.rs

@@ -22,6 +22,7 @@ use watch::{
 };
 
 use log::error;
+use std::env;
 use std::net::SocketAddr;
 use std::time::Duration;
 use tokio::{runtime, task::JoinHandle};
@@ -36,6 +37,11 @@ const VALIDATOR_COUNT: usize = 32;
 const SLOTS_PER_EPOCH: u64 = 32;
 const DEFAULT_TIMEOUT: Duration = Duration::from_secs(5);
 
+/// Set this environment variable to use a different hostname for connecting to
+/// the database. Can be set to `host.docker.internal` for docker-in-docker
+/// setups.
+const WATCH_HOST_ENV_VARIABLE: &str = "WATCH_HOST";
+
 fn build_test_config(config: &DatabaseConfig) -> PostgresConfig {
     let mut postgres_config = PostgresConfig::new();
     postgres_config
@@ -71,6 +77,10 @@ pub async fn create_test_database(config: &DatabaseConfig) {
         .expect("Database creation failed");
 }
 
+pub fn get_host_from_env() -> String {
+    env::var(WATCH_HOST_ENV_VARIABLE).unwrap_or_else(|_| "localhost".to_string())
+}
+
 struct TesterBuilder {
     pub harness: BeaconChainHarness<EphemeralHarnessType<E>>,
     pub config: Config,
@@ -107,6 +117,7 @@ impl TesterBuilder {
             database: DatabaseConfig {
                 dbname: random_dbname(),
                 port: database_port,
+                host: get_host_from_env(),
                 ..Default::default()
             },
             server: ServerConfig {