Implement validator_identities Beacon API endpoint (#7462)

* #7442

beacon_node/http_api/src/lib.rs

@@ -48,7 +48,8 @@ use directory::DEFAULT_ROOT_DIR;
 use eth2::types::{
     self as api_types, BroadcastValidation, ContextDeserialize, EndpointVersion, ForkChoice,
     ForkChoiceNode, LightClientUpdatesQuery, PublishBlockRequest, StateId as CoreStateId,
-    ValidatorBalancesRequestBody, ValidatorId, ValidatorStatus, ValidatorsRequestBody,
+    ValidatorBalancesRequestBody, ValidatorId, ValidatorIdentitiesRequestBody, ValidatorStatus,
+    ValidatorsRequestBody,
 };
 use eth2::{CONSENSUS_VERSION_HEADER, CONTENT_TYPE_HEADER, SSZ_CONTENT_TYPE_HEADER};
 use health_metrics::observe::Observe;
@@ -702,6 +703,34 @@ pub fn serve<T: BeaconChainTypes>(
             },
         );
 
+    // POST beacon/states/{state_id}/validator_identities
+    let post_beacon_state_validator_identities = beacon_states_path
+        .clone()
+        .and(warp::path("validator_identities"))
+        .and(warp::path::end())
+        .and(warp_utils::json::json_no_body())
+        .then(
+            |state_id: StateId,
+             task_spawner: TaskSpawner<T::EthSpec>,
+             chain: Arc<BeaconChain<T>>,
+             query: ValidatorIdentitiesRequestBody| {
+                // Prioritise requests for validators at the head. These should be fast to service
+                // and could be required by the validator client.
+                let priority = if let StateId(eth2::types::StateId::Head) = state_id {
+                    Priority::P0
+                } else {
+                    Priority::P1
+                };
+                task_spawner.blocking_json_task(priority, move || {
+                    crate::validators::get_beacon_state_validator_identities(
+                        state_id,
+                        chain,
+                        Some(&query.ids),
+                    )
+                })
+            },
+        );
+
     // GET beacon/states/{state_id}/validators?id,status
     let get_beacon_state_validators = beacon_states_path
         .clone()
@@ -4852,6 +4881,7 @@ pub fn serve<T: BeaconChainTypes>(
                     .uor(post_beacon_pool_bls_to_execution_changes)
                     .uor(post_beacon_state_validators)
                     .uor(post_beacon_state_validator_balances)
+                    .uor(post_beacon_state_validator_identities)
                     .uor(post_beacon_rewards_attestations)
                     .uor(post_beacon_rewards_sync_committee)
                     .uor(post_validator_duties_attester)

beacon_node/http_api/src/validators.rs

@@ -2,7 +2,7 @@ use crate::state_id::StateId;
 use beacon_chain::{BeaconChain, BeaconChainTypes};
 use eth2::types::{
     self as api_types, ExecutionOptimisticFinalizedResponse, ValidatorBalanceData, ValidatorData,
-    ValidatorId, ValidatorStatus,
+    ValidatorId, ValidatorIdentityData, ValidatorStatus,
 };
 use std::{collections::HashSet, sync::Arc};
 
@@ -119,3 +119,51 @@ pub fn get_beacon_state_validator_balances<T: BeaconChainTypes>(
         finalized: Some(finalized),
     })
 }
+
+pub fn get_beacon_state_validator_identities<T: BeaconChainTypes>(
+    state_id: StateId,
+    chain: Arc<BeaconChain<T>>,
+    optional_ids: Option<&[ValidatorId]>,
+) -> Result<ExecutionOptimisticFinalizedResponse<Vec<ValidatorIdentityData>>, warp::Rejection> {
+    let (data, execution_optimistic, finalized) = state_id
+        .map_state_and_execution_optimistic_and_finalized(
+            &chain,
+            |state, execution_optimistic, finalized| {
+                let ids_filter_set: Option<HashSet<&ValidatorId>> = match optional_ids {
+                    // Same logic as validator_balances endpoint above
+                    Some([]) => None,
+                    Some(ids) => Some(HashSet::from_iter(ids.iter())),
+                    None => None,
+                };
+
+                Ok((
+                    // From the BeaconState, extract the Validator data and convert it into ValidatorIdentityData type
+                    state
+                        .validators()
+                        .iter()
+                        .enumerate()
+                        // filter by validator id(s) if provided
+                        .filter(|(index, validator)| {
+                            ids_filter_set.as_ref().is_none_or(|ids_set| {
+                                ids_set.contains(&ValidatorId::PublicKey(validator.pubkey))
+                                    || ids_set.contains(&ValidatorId::Index(*index as u64))
+                            })
+                        })
+                        .map(|(index, validator)| ValidatorIdentityData {
+                            index: index as u64,
+                            pubkey: validator.pubkey,
+                            activation_epoch: validator.activation_epoch,
+                        })
+                        .collect::<Vec<_>>(),
+                    execution_optimistic,
+                    finalized,
+                ))
+            },
+        )?;
+
+    Ok(api_types::ExecutionOptimisticFinalizedResponse {
+        data,
+        execution_optimistic: Some(execution_optimistic),
+        finalized: Some(finalized),
+    })
+}

beacon_node/http_api/tests/tests.rs

@@ -964,6 +964,87 @@ impl ApiTester {
         self
     }
 
+    pub async fn test_beacon_states_validator_identities(self) -> Self {
+        for state_id in self.interesting_state_ids() {
+            for validator_indices in self.interesting_validator_indices() {
+                let state_opt = state_id.state(&self.chain).ok();
+                let validators: Vec<Validator> = match state_opt.as_ref() {
+                    Some((state, _execution_optimistic, _finalized)) => {
+                        state.validators().clone().to_vec()
+                    }
+                    None => vec![],
+                };
+
+                let validator_index_ids = validator_indices
+                    .iter()
+                    .cloned()
+                    .map(ValidatorId::Index)
+                    .collect::<Vec<ValidatorId>>();
+
+                let validator_pubkey_ids = validator_indices
+                    .iter()
+                    .cloned()
+                    .map(|i| {
+                        ValidatorId::PublicKey(
+                            validators
+                                .get(i as usize)
+                                .map_or(PublicKeyBytes::empty(), |val| val.pubkey),
+                        )
+                    })
+                    .collect::<Vec<ValidatorId>>();
+
+                let result_index_ids = self
+                    .client
+                    .post_beacon_states_validator_identities(state_id.0, validator_index_ids)
+                    .await
+                    .unwrap()
+                    .map(|res| res.data);
+                let result_pubkey_ids = self
+                    .client
+                    .post_beacon_states_validator_identities(state_id.0, validator_pubkey_ids)
+                    .await
+                    .unwrap()
+                    .map(|res| res.data);
+
+                let expected = state_opt.map(|(state, _execution_optimistic, _finalized)| {
+                    // If validator_indices is empty, return identities for all validators
+                    if validator_indices.is_empty() {
+                        state
+                            .validators()
+                            .iter()
+                            .enumerate()
+                            .map(|(index, validator)| ValidatorIdentityData {
+                                index: index as u64,
+                                pubkey: validator.pubkey,
+                                activation_epoch: validator.activation_epoch,
+                            })
+                            .collect()
+                    } else {
+                        let mut validators = Vec::with_capacity(validator_indices.len());
+
+                        for i in validator_indices {
+                            if i < state.validators().len() as u64 {
+                                // access each validator, and then transform the data into ValidatorIdentityData
+                                let validator = state.validators().get(i as usize).unwrap();
+                                validators.push(ValidatorIdentityData {
+                                    index: i,
+                                    pubkey: validator.pubkey,
+                                    activation_epoch: validator.activation_epoch,
+                                });
+                            }
+                        }
+
+                        validators
+                    }
+                });
+
+                assert_eq!(result_index_ids, expected, "{:?}", state_id);
+                assert_eq!(result_pubkey_ids, expected, "{:?}", state_id);
+            }
+        }
+        self
+    }
+
     pub async fn test_beacon_states_validators(self) -> Self {
         for state_id in self.interesting_state_ids() {
             for statuses in self.interesting_validator_statuses() {
@@ -6685,6 +6766,8 @@ async fn beacon_get_state_info() {
         .await
         .test_beacon_states_validator_balances()
         .await
+        .test_beacon_states_validator_identities()
+        .await
         .test_beacon_states_committees()
         .await
         .test_beacon_states_validator_id()