Rename random to prev_randao (#3040)

## Issue Addressed

As discussed on last-night's consensus call, the testnets next week will target the [Kiln Spec v2](https://hackmd.io/@n0ble/kiln-spec).

Presently, we support Kiln V1. V2 is backwards compatible, except for renaming `random` to `prev_randao` in:

- https://github.com/ethereum/execution-apis/pull/180
- https://github.com/ethereum/consensus-specs/pull/2835

With this PR we'll no longer be compatible with the existing Kintsugi and Kiln testnets, however we'll be ready for the testnets next week. I raised this breaking change in the call last night, we are all keen to move forward and break things.

We now target the [`merge-kiln-v2`](https://github.com/MariusVanDerWijden/go-ethereum/tree/merge-kiln-v2) branch for interop with Geth. This required adding the `--http.aauthport` to the tester to avoid a port conflict at startup.

### Changes to exec integration tests

There's some change in the `merge-kiln-v2` version of Geth that means it can't compile on a vanilla Github runner. Bumping the `go` version on the runner solved this issue.

Whilst addressing this, I refactored the `testing/execution_integration` crate to be a *binary* rather than a *library* with tests. This means that we don't need to run the `build.rs` and build Geth whenever someone runs `make lint` or `make test-release`. This is nice for everyday users, but it's also nice for CI so that we can have a specific runner for these tests and we don't need to ensure *all* runners support everything required to build all execution clients.

## More Info

- [x] ~~EF tests are failing since the rename has broken some tests that reference the old field name. I have been told there will be new tests released in the coming days (25/02/22 or 26/02/22).~~

testing/execution_engine_integration/src/build_geth.rs

@@ -0,0 +1,66 @@
+use std::env;
+use std::fs;
+use std::path::{Path, PathBuf};
+use std::process::Command;
+
+const GETH_BRANCH: &str = "merge-kiln-v2";
+const GETH_REPO_URL: &str = "https://github.com/MariusVanDerWijden/go-ethereum";
+
+pub fn build() {
+    let manifest_dir: PathBuf = env::var("CARGO_MANIFEST_DIR").unwrap().into();
+    let execution_clients_dir = manifest_dir.join("execution_clients");
+
+    if !execution_clients_dir.exists() {
+        fs::create_dir(&execution_clients_dir).unwrap();
+    }
+
+    build_geth(&execution_clients_dir);
+}
+
+fn build_geth(execution_clients_dir: &Path) {
+    let repo_dir = execution_clients_dir.join("go-ethereum");
+
+    if !repo_dir.exists() {
+        // Clone the repo
+        assert!(Command::new("git")
+            .arg("clone")
+            .arg(GETH_REPO_URL)
+            .current_dir(&execution_clients_dir)
+            .output()
+            .expect("failed to clone geth repo")
+            .status
+            .success());
+    }
+
+    // Checkout the correct branch
+    assert!(Command::new("git")
+        .arg("checkout")
+        .arg(GETH_BRANCH)
+        .current_dir(&repo_dir)
+        .output()
+        .expect("failed to checkout geth branch")
+        .status
+        .success());
+
+    // Update the branch
+    assert!(Command::new("git")
+        .arg("pull")
+        .current_dir(&repo_dir)
+        .output()
+        .expect("failed to update geth branch")
+        .status
+        .success());
+
+    // Build geth
+    let make_result = Command::new("make")
+        .arg("geth")
+        .current_dir(&repo_dir)
+        .output()
+        .expect("failed to make geth");
+
+    if !make_result.status.success() {
+        dbg!(String::from_utf8_lossy(&make_result.stdout));
+        dbg!(String::from_utf8_lossy(&make_result.stderr));
+        panic!("make failed");
+    }
+}

testing/execution_engine_integration/src/execution_engine.rs

@@ -9,7 +9,7 @@ use unused_port::unused_tcp_port;
 /// Defined for each EE type (e.g., Geth, Nethermind, etc).
 pub trait GenericExecutionEngine: Clone {
     fn init_datadir() -> TempDir;
-    fn start_client(datadir: &TempDir, http_port: u16) -> Child;
+    fn start_client(datadir: &TempDir, http_port: u16, http_auth_port: u16) -> Child;
 }
 
 /// Holds handle to a running EE process, plus some other metadata.
@@ -19,6 +19,7 @@ pub struct ExecutionEngine<E> {
     #[allow(dead_code)]
     datadir: TempDir,
     http_port: u16,
+    http_auth_port: u16,
     child: Child,
 }
 
@@ -35,11 +36,13 @@ impl<E: GenericExecutionEngine> ExecutionEngine<E> {
     pub fn new(engine: E) -> Self {
         let datadir = E::init_datadir();
         let http_port = unused_tcp_port().unwrap();
-        let child = E::start_client(&datadir, http_port);
+        let http_auth_port = unused_tcp_port().unwrap();
+        let child = E::start_client(&datadir, http_port, http_auth_port);
         Self {
             engine,
             datadir,
             http_port,
+            http_auth_port,
             child,
         }
     }
@@ -47,6 +50,11 @@ impl<E: GenericExecutionEngine> ExecutionEngine<E> {
     pub fn http_url(&self) -> SensitiveUrl {
         SensitiveUrl::parse(&format!("http://127.0.0.1:{}", self.http_port)).unwrap()
     }
+
+    #[allow(dead_code)] // Future use.
+    pub fn http_ath_url(&self) -> SensitiveUrl {
+        SensitiveUrl::parse(&format!("http://127.0.0.1:{}", self.http_auth_port)).unwrap()
+    }
 }
 
 /*
@@ -90,7 +98,7 @@ impl GenericExecutionEngine for Geth {
         datadir
     }
 
-    fn start_client(datadir: &TempDir, http_port: u16) -> Child {
+    fn start_client(datadir: &TempDir, http_port: u16, http_auth_port: u16) -> Child {
         let network_port = unused_tcp_port().unwrap();
 
         Command::new(Self::binary_path())
@@ -101,6 +109,8 @@ impl GenericExecutionEngine for Geth {
             .arg("engine,eth")
             .arg("--http.port")
             .arg(http_port.to_string())
+            .arg("--http.authport")
+            .arg(http_auth_port.to_string())
             .arg("--port")
             .arg(network_port.to_string())
             .stdout(build_stdio())

testing/execution_engine_integration/src/lib.rs

@@ -1,12 +0,0 @@
-/// This library provides integration testing between Lighthouse and other execution engines.
-///
-/// See the `tests/tests.rs` file to run tests.
-mod execution_engine;
-mod genesis_json;
-mod test_rig;
-
-pub use execution_engine::Geth;
-pub use test_rig::TestRig;
-
-/// Set to `false` to send logs to the console during tests. Logs are useful when debugging.
-const SUPPRESS_LOGS: bool = true;

testing/execution_engine_integration/src/main.rs

@@ -0,0 +1,28 @@
+/// This binary runs integration tests between Lighthouse and execution engines.
+///
+/// It will first attempt to build any supported integration clients, then it will run tests.
+///
+/// A return code of `0` indicates the tests succeeded.
+mod build_geth;
+mod execution_engine;
+mod genesis_json;
+mod test_rig;
+
+use execution_engine::Geth;
+use test_rig::TestRig;
+
+/// Set to `false` to send logs to the console during tests. Logs are useful when debugging.
+const SUPPRESS_LOGS: bool = false;
+
+fn main() {
+    if cfg!(windows) {
+        panic!("windows is not supported, only linux");
+    }
+
+    test_geth()
+}
+
+fn test_geth() {
+    build_geth::build();
+    TestRig::new(Geth).perform_tests_blocking();
+}

testing/execution_engine_integration/src/test_rig.rs

@@ -138,7 +138,7 @@ impl<E: GenericExecutionEngine> TestRig<E> {
 
         let parent_hash = terminal_pow_block_hash;
         let timestamp = timestamp_now();
-        let random = Hash256::zero();
+        let prev_randao = Hash256::zero();
         let finalized_block_hash = ExecutionBlockHash::zero();
         let proposer_index = 0;
         let valid_payload = self
@@ -147,7 +147,7 @@ impl<E: GenericExecutionEngine> TestRig<E> {
             .get_payload::<MainnetEthSpec>(
                 parent_hash,
                 timestamp,
-                random,
+                prev_randao,
                 finalized_block_hash,
                 proposer_index,
             )
@@ -210,7 +210,7 @@ impl<E: GenericExecutionEngine> TestRig<E> {
          */
 
         let mut invalid_payload = valid_payload.clone();
-        invalid_payload.random = Hash256::from_low_u64_be(42);
+        invalid_payload.prev_randao = Hash256::from_low_u64_be(42);
         let status = self
             .ee_a
             .execution_layer
@@ -227,7 +227,7 @@ impl<E: GenericExecutionEngine> TestRig<E> {
 
         let parent_hash = valid_payload.block_hash;
         let timestamp = valid_payload.timestamp + 1;
-        let random = Hash256::zero();
+        let prev_randao = Hash256::zero();
         let finalized_block_hash = ExecutionBlockHash::zero();
         let proposer_index = 0;
         let second_payload = self
@@ -236,7 +236,7 @@ impl<E: GenericExecutionEngine> TestRig<E> {
             .get_payload::<MainnetEthSpec>(
                 parent_hash,
                 timestamp,
-                random,
+                prev_randao,
                 finalized_block_hash,
                 proposer_index,
             )
@@ -266,7 +266,7 @@ impl<E: GenericExecutionEngine> TestRig<E> {
         let finalized_block_hash = ExecutionBlockHash::zero();
         let payload_attributes = Some(PayloadAttributes {
             timestamp: second_payload.timestamp + 1,
-            random: Hash256::zero(),
+            prev_randao: Hash256::zero(),
             suggested_fee_recipient: Address::zero(),
         });
         let status = self