Add ChainStart Delay Flag (#1591)

* add flag

* log formatting

* fix test

* do not process logs if flag is enabled

beacon-chain/main.go

@@ -71,6 +71,7 @@ VERSION:
 		utils.GenesisJSON,
 		utils.EnablePOWChain,
 		utils.EnableDBCleanup,
+		utils.ChainStartDelay,
 		cmd.BootstrapNode,
 		cmd.RelayNode,
 		cmd.P2PPort,

beacon-chain/node/node.go

@@ -207,6 +207,8 @@ func (b *BeaconNode) registerPOWChainService(ctx *cli.Context) error {
 	}
 	powClient := ethclient.NewClient(rpcClient)
 
+	delay := ctx.GlobalUint64(utils.ChainStartDelay.Name)
+
 	web3Service, err := powchain.NewWeb3Service(context.TODO(), &powchain.Web3ServiceConfig{
 		Endpoint:        b.ctx.GlobalString(utils.Web3ProviderFlag.Name),
 		DepositContract: common.HexToAddress(b.ctx.GlobalString(utils.DepositContractFlag.Name)),
@@ -215,6 +217,7 @@ func (b *BeaconNode) registerPOWChainService(ctx *cli.Context) error {
 		Logger:          powClient,
 		ContractBackend: powClient,
 		BeaconDB:        b.db,
+		ChainStartDelay: delay,
 	})
 	if err != nil {
 		return fmt.Errorf("could not register proof-of-work chain web3Service: %v", err)

beacon-chain/powchain/service.go

@@ -89,6 +89,7 @@ type Web3Service struct {
 	chainStarted            bool
 	beaconDB                *db.BeaconDB
 	lastReceivedMerkleIndex int64 // Keeps track of the last received index to prevent log spam.
+	chainStartDelay         uint64
 }
 
 // Web3ServiceConfig defines a config struct for web3 service to use through its life cycle.
@@ -100,6 +101,7 @@ type Web3ServiceConfig struct {
 	Logger          bind.ContractFilterer
 	ContractBackend bind.ContractBackend
 	BeaconDB        *db.BeaconDB
+	ChainStartDelay uint64
 }
 
 var (
@@ -140,6 +142,7 @@ func NewWeb3Service(ctx context.Context, config *Web3ServiceConfig) (*Web3Servic
 		chainStartDeposits:      []*pb.Deposit{},
 		beaconDB:                config.BeaconDB,
 		lastReceivedMerkleIndex: -1,
+		chainStartDelay:         config.ChainStartDelay,
 	}, nil
 }
 
@@ -149,6 +152,10 @@ func (w *Web3Service) Start() {
 		"endpoint": w.endpoint,
 	}).Info("Starting service")
 	go w.run(w.ctx.Done())
+
+	if w.chainStartDelay > 0 {
+		go w.runDelayTimer(w.ctx.Done())
+	}
 }
 
 // Stop the web3 service's main event loop and associated goroutines.
@@ -291,10 +298,32 @@ func (w *Web3Service) ProcessChainStartLog(depositLog gethTypes.Log) {
 	chainStartTime := time.Unix(int64(timestamp), 0)
 	log.WithFields(logrus.Fields{
 		"ChainStartTime": chainStartTime,
-	}).Info("Minimum Number of Validators Reached for beacon-chain to start")
+	}).Info("Minimum number of validators reached for beacon-chain to start")
 	w.chainStartFeed.Send(chainStartTime)
 }
 
+func (w *Web3Service) runDelayTimer(done <-chan struct{}) {
+	timer := time.NewTimer(time.Duration(w.chainStartDelay) * time.Second)
+
+	for {
+		select {
+		case <-done:
+			log.Debug("ETH1.0 chain service context closed, exiting goroutine")
+			timer.Stop()
+			return
+		case currentTime := <-timer.C:
+
+			w.chainStarted = true
+			log.WithFields(logrus.Fields{
+				"ChainStartTime": currentTime.Unix(),
+			}).Info("Minimum number of validators reached for beacon-chain to start")
+			w.chainStartFeed.Send(currentTime)
+			timer.Stop()
+			return
+		}
+	}
+}
+
 // run subscribes to all the services for the ETH1.0 chain.
 func (w *Web3Service) run(done <-chan struct{}) {
 	if err := w.initDataFromContract(); err != nil {
@@ -323,9 +352,13 @@ func (w *Web3Service) run(done <-chan struct{}) {
 		log.Errorf("Unable to query logs from deposit contract: %v", err)
 		return
 	}
-	if err := w.processPastLogs(query); err != nil {
+
-		log.Errorf("Unable to process past logs %v", err)
+	// Only process logs if the chain start delay flag is not enabled.
-		return
+	if w.chainStartDelay == 0 {
+		if err := w.processPastLogs(query); err != nil {
+			log.Errorf("Unable to process past logs %v", err)
+			return
+		}
 	}
 	defer logSub.Unsubscribe()
 	defer headSub.Unsubscribe()

beacon-chain/powchain/service_test.go

@@ -777,7 +777,7 @@ func TestProcessChainStartLog(t *testing.T) {
 	testutil.AssertLogsDoNotContain(t, hook, "Unable to unpack ChainStart log data")
 	testutil.AssertLogsDoNotContain(t, hook, "Receipt root from log doesn't match the root saved in memory")
 	testutil.AssertLogsDoNotContain(t, hook, "Invalid timestamp from log")
-	testutil.AssertLogsContain(t, hook, "Minimum Number of Validators Reached for beacon-chain to start")
+	testutil.AssertLogsContain(t, hook, "Minimum number of validators reached for beacon-chain to start")
 
 	hook.Reset()
 

beacon-chain/utils/flags.go

@@ -54,4 +54,10 @@ var (
 		Name:  "enable-db-cleanup",
 		Usage: "Enable automatic DB cleanup routine",
 	}
+	// ChainStartDelay tells the beacon node to wait for a period of time from the current time, before
+	// logging chainstart.
+	ChainStartDelay = cli.Uint64Flag{
+		Name:  "chain-start-delay",
+		Usage: "Delay the chain start so as to make local testing easier",
+	}
 )