do not start indexer/synchronizer when beacon node is synchronizing

indexer/indexer.go

@@ -254,18 +254,38 @@ func (indexer *Indexer) runIndexer() {
 	defer indexer.runMutex.Unlock()
 
 	for {
+		runIndexerLoop := true
+
 		genesis, err := indexer.rpcClient.GetGenesis()
 		if err != nil {
 			logger.Errorf("Indexer Error while fetching genesis: %v", err)
+			runIndexerLoop = false
 		} else if genesis != nil {
 			genesisTime := uint64(genesis.Data.GenesisTime)
 			if genesisTime != utils.Config.Chain.GenesisTimestamp {
 				logger.Warnf("Genesis time from RPC does not match the genesis time from explorer configuration.")
+				runIndexerLoop = false
 			}
 			if genesis.Data.GenesisForkVersion.String() != utils.Config.Chain.Config.GenesisForkVersion {
 				logger.Warnf("Genesis fork version from RPC does not match the genesis fork version explorer configuration.")
+				runIndexerLoop = false
 			}
+		}
+
+		if runIndexerLoop {
+			syncStatus, err := indexer.rpcClient.GetNodeSyncing()
+			if err != nil {
+				logger.Errorf("Indexer Error while fetching syncing status: %v", err)
+				runIndexerLoop = false
+			} else if syncStatus != nil {
+				if syncStatus.Data.IsSyncing {
+					logger.Errorf("Cannot run indexer, beacon node is synchronizing.")
+					runIndexerLoop = false
+				}
+			}
+		}
 
+		if runIndexerLoop {
 			err := indexer.runIndexerLoop()
 			if err == nil {
 				break

rpc/beaconapi.go

@@ -109,6 +109,24 @@ func (bc *BeaconClient) GetGenesis() (*rpctypes.StandardV1GenesisResponse, error
 	return &parsedGenesis, nil
 }
 
+func (bc *BeaconClient) GetNodeSyncing() (*rpctypes.StandardV1NodeSyncingResponse, error) {
+	resGenesis, err := bc.get(fmt.Sprintf("%s/eth/v1/node/syncing", bc.endpoint))
+	if err != nil {
+		if err == errNotFound {
+			// no block found
+			return nil, nil
+		}
+		return nil, fmt.Errorf("error retrieving syncing status: %v", err)
+	}
+
+	var parsedSyncingStatus rpctypes.StandardV1NodeSyncingResponse
+	err = json.Unmarshal(resGenesis, &parsedSyncingStatus)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing syncing status response: %v", err)
+	}
+	return &parsedSyncingStatus, nil
+}
+
 func (bc *BeaconClient) GetLatestBlockHead() (*rpctypes.StandardV1BeaconHeaderResponse, error) {
 	resHeaders, err := bc.get(fmt.Sprintf("%s/eth/v1/beacon/headers/head", bc.endpoint))
 	if err != nil {

rpctypes/beaconapi.go

@@ -93,3 +93,13 @@ type StandardV1GenesisResponse struct {
 type StandardV1BlobSidecarsResponse struct {
 	Data []BlobSidecar `json:"data"`
 }
+
+type StandardV1NodeSyncingResponse struct {
+	Data struct {
+		HeadSlot     Uint64Str `json:"head_slot"`
+		SyncDistance Uint64Str `json:"sync_distance"`
+		IsSyncing    bool      `json:"is_syncing"`
+		IsOptimistic bool      `json:"is_optimistic"`
+		ElOffline    bool      `json:"el_offline"`
+	} `json:"data"`
+}