add metrics::VALIDATOR_DUTIES_SYNC_HTTP_POST for `post_validator_du…

…ties_sync` (#4617)

It seems `post_validator_duties_sync` is the only api which doesn't have its own metric in `duties_service`, this PR adds `metrics::VALIDATOR_DUTIES_SYNC_HTTP_POST` for completeness.

validator_client/src/duties_service/sync.rs

@@ -2,8 +2,10 @@ use crate::beacon_node_fallback::{OfflineOnFailure, RequireSynced};
 use crate::{
     doppelganger_service::DoppelgangerStatus,
     duties_service::{DutiesService, Error},
+    http_metrics::metrics,
     validator_store::Error as ValidatorStoreError,
 };
+
 use futures::future::join_all;
 use itertools::Itertools;
 use parking_lot::{MappedRwLockReadGuard, RwLock, RwLockReadGuard, RwLockWriteGuard};
@@ -426,6 +428,10 @@ pub async fn poll_sync_committee_duties_for_period<T: SlotClock + 'static, E: Et
             RequireSynced::No,
             OfflineOnFailure::Yes,
             |beacon_node| async move {
+                let _timer = metrics::start_timer_vec(
+                    &metrics::DUTIES_SERVICE_TIMES,
+                    &[metrics::VALIDATOR_DUTIES_SYNC_HTTP_POST],
+                );
                 beacon_node
                     .post_validator_duties_sync(period_start_epoch, local_indices)
                     .await

validator_client/src/http_metrics/metrics.rs

@@ -29,6 +29,7 @@ pub const UPDATE_ATTESTERS_FETCH: &str = "update_attesters_fetch";
 pub const UPDATE_ATTESTERS_STORE: &str = "update_attesters_store";
 pub const ATTESTER_DUTIES_HTTP_POST: &str = "attester_duties_http_post";
 pub const PROPOSER_DUTIES_HTTP_GET: &str = "proposer_duties_http_get";
+pub const VALIDATOR_DUTIES_SYNC_HTTP_POST: &str = "validator_duties_sync_http_post";
 pub const VALIDATOR_ID_HTTP_GET: &str = "validator_id_http_get";
 pub const SUBSCRIPTIONS_HTTP_POST: &str = "subscriptions_http_post";
 pub const UPDATE_PROPOSERS: &str = "update_proposers";