Eagerly sign sync committee messages on head events

book/src/help_vc.md

@@ -187,11 +187,11 @@ Flags:
           validators-dir. Validators will need to be manually added to the
           validator_definitions.yml file.
       --disable-beacon-head-monitor
-          Disable the beacon head monitor which tries to attest as soon as any
-          of the configured beacon nodes sends a head event. Leaving the service
-          enabled is recommended, but disabling it can lead to reduced bandwidth
-          and more predictable usage of the primary beacon node (rather than the
-          fastest BN).
+          Disable the beacon head monitor which triggers attestations and sync
+          committee messages when a configured beacon node sends a head event.
+          Leaving it enabled is recommended, but disabling it can lead to
+          reduced bandwidth and more predictable usage of the primary beacon
+          node (rather than the fastest BN).
       --disable-latency-measurement-service
           Disables the service that periodically attempts to measure latency to
           BNs.

testing/validator_test_rig/src/mock_beacon_node.rs

@@ -1,5 +1,5 @@
 use eth2::types::{
-    GenericResponse, ProduceBlockV4Response, PublishBlockRequest,
+    GenericResponse, ProduceBlockV4Response, PublishBlockRequest, RootData,
     SignedExecutionPayloadEnvelopeContents, SubmittedBuilderPreferences, SyncingData,
 };
 use eth2::{BLOB_DATA_INCLUDED_HEADER, BeaconNodeHttpClient, CONSENSUS_VERSION_HEADER, Timeouts};
@@ -14,9 +14,10 @@ use std::sync::{Arc, Mutex};
 use std::time::Duration;
 use tracing::info;
 use types::{
-    ChainSpec, ConfigAndPreset, EthSpec, ExecutionPayloadEnvelope, ForkName, Hash256,
+    ChainSpec, ConfigAndPreset, Epoch, EthSpec, ExecutionPayloadEnvelope, ForkName, Hash256,
     PayloadAttestationData, PayloadAttestationMessage, SignedBlindedBeaconBlock,
-    SignedExecutionPayloadEnvelope, Slot,
+    SignedContributionAndProof, SignedExecutionPayloadEnvelope, Slot, SyncCommitteeContribution,
+    SyncCommitteeMessage, SyncDuty,
 };
 
 pub struct MockBeaconNode<E: EthSpec> {
@@ -30,6 +31,8 @@ pub struct MockBeaconNode<E: EthSpec> {
         Arc<Mutex<Vec<SignedExecutionPayloadEnvelopeContents<E>>>>,
     pub payload_attestation_message: Arc<Mutex<Vec<PayloadAttestationMessage>>>,
     pub builder_preferences: Arc<Mutex<Vec<SubmittedBuilderPreferences>>>,
+    pub sync_committee_messages: Arc<Mutex<Vec<SyncCommitteeMessage>>>,
+    pub sync_committee_contributions: Arc<Mutex<Vec<SignedContributionAndProof<E>>>>,
 }
 
 impl<E: EthSpec> MockBeaconNode<E> {
@@ -50,6 +53,8 @@ impl<E: EthSpec> MockBeaconNode<E> {
             execution_payload_envelope_contents: Arc::new(Mutex::new(Vec::new())),
             payload_attestation_message: Arc::new(Mutex::new(Vec::new())),
             builder_preferences: Arc::new(Mutex::new(Vec::new())),
+            sync_committee_messages: Arc::new(Mutex::new(Vec::new())),
+            sync_committee_contributions: Arc::new(Mutex::new(Vec::new())),
         }
     }
 
@@ -110,6 +115,116 @@ impl<E: EthSpec> MockBeaconNode<E> {
             .create();
     }
 
+    /// Mocks `POST /eth/v1/validator/duties/sync/{epoch}`
+    pub fn mock_sync_duties(&mut self, epoch: Epoch, duties: Vec<SyncDuty>) -> Mock {
+        let path_pattern = Regex::new(&format!(
+            r"^/eth/v1/validator/duties/sync/{}$",
+            epoch.as_u64()
+        ))
+        .unwrap();
+        let response =
+            GenericResponse::from(duties).add_execution_optimistic_finalized(false, false);
+
+        self.server
+            .mock("POST", Matcher::Regex(path_pattern.to_string()))
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .with_body(serde_json::to_string(&response).unwrap())
+            .create()
+    }
+
+    /// Mocks `GET /eth/v1/beacon/blocks/head/root`
+    pub fn mock_get_head_block_root(&mut self, root: Hash256) -> Mock {
+        let path_pattern = Regex::new(r"^/eth/v1/beacon/blocks/head/root$").unwrap();
+        let response = GenericResponse::from(RootData { root })
+            .add_execution_optimistic_finalized(false, false);
+
+        self.server
+            .mock("GET", Matcher::Regex(path_pattern.to_string()))
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .with_body(serde_json::to_string(&response).unwrap())
+            .create()
+    }
+
+    /// Mocks `POST /eth/v1/beacon/pool/sync_committees`
+    pub fn mock_post_sync_committee_messages(&mut self) -> Mock {
+        let path_pattern = Regex::new(r"^/eth/v1/beacon/pool/sync_committees$").unwrap();
+        let sync_committee_messages = Arc::clone(&self.sync_committee_messages);
+
+        self.server
+            .mock("POST", Matcher::Regex(path_pattern.to_string()))
+            .with_status(200)
+            .with_body_from_request(move |request| {
+                let body = request.body().expect("Failed to get request body");
+                let messages: Vec<SyncCommitteeMessage> = serde_json::from_slice(body)
+                    .expect("Failed to deserialize sync committee messages");
+                sync_committee_messages.lock().unwrap().extend(messages);
+                vec![]
+            })
+            .create()
+    }
+
+    /// Mocks `GET /eth/v1/validator/sync_committee_contribution`, matching the slot, block root
+    /// and subcommittee index of `contribution`.
+    pub fn mock_get_sync_committee_contribution(
+        &mut self,
+        contribution: &SyncCommitteeContribution<E>,
+    ) -> Mock {
+        let path_pattern = Regex::new(r"^/eth/v1/validator/sync_committee_contribution$").unwrap();
+        let response = GenericResponse::from(contribution.clone());
+
+        self.server
+            .mock("GET", Matcher::Regex(path_pattern.to_string()))
+            .match_query(Matcher::AllOf(vec![
+                Matcher::UrlEncoded("slot".into(), contribution.slot.to_string()),
+                Matcher::UrlEncoded(
+                    "beacon_block_root".into(),
+                    format!("{:?}", contribution.beacon_block_root),
+                ),
+                Matcher::UrlEncoded(
+                    "subcommittee_index".into(),
+                    contribution.subcommittee_index.to_string(),
+                ),
+            ]))
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .with_body(serde_json::to_string(&response).unwrap())
+            .create()
+    }
+
+    /// Mocks `POST /eth/v1/validator/contribution_and_proofs`
+    pub fn mock_post_contribution_and_proofs(&mut self) -> Mock {
+        let path_pattern = Regex::new(r"^/eth/v1/validator/contribution_and_proofs$").unwrap();
+        let sync_committee_contributions = Arc::clone(&self.sync_committee_contributions);
+
+        self.server
+            .mock("POST", Matcher::Regex(path_pattern.to_string()))
+            .with_status(200)
+            .with_body_from_request(move |request| {
+                let body = request.body().expect("Failed to get request body");
+                let contributions: Vec<SignedContributionAndProof<E>> =
+                    serde_json::from_slice(body)
+                        .expect("Failed to deserialize sync committee contributions");
+                sync_committee_contributions
+                    .lock()
+                    .unwrap()
+                    .extend(contributions);
+                vec![]
+            })
+            .create()
+    }
+
+    /// Mocks `POST /eth/v1/validator/sync_committee_subscriptions`
+    pub fn mock_sync_committee_subscriptions(&mut self) -> Mock {
+        let path_pattern = Regex::new(r"^/eth/v1/validator/sync_committee_subscriptions$").unwrap();
+
+        self.server
+            .mock("POST", Matcher::Regex(path_pattern.to_string()))
+            .with_status(200)
+            .create()
+    }
+
     /// Mocks `POST /eth/v4/validator/blocks/{slot}`, matching the given `include_payload` query
     /// value and answering with `response`.
     pub fn mock_post_validator_blocks_v4(

testing/validator_test_rig/src/validator_client_harness.rs

@@ -51,7 +51,6 @@ impl ValidatorClientHarness {
         config: &ValidatorStoreConfig,
     ) -> Self {
         let spec = Arc::new(spec);
-
         let test_runtime = TestRuntime::default();
         let executor = test_runtime.task_executor.clone();
         let slot_duration = spec.get_slot_duration();

validator_client/beacon_node_fallback/Cargo.toml

@@ -25,4 +25,5 @@ types = { workspace = true }
 validator_metrics = { workspace = true }
 
 [dev-dependencies]
+tokio = { workspace = true, features = ["test-util"] }
 validator_test_rig = { workspace = true }