Add --rpc-host option to beacon chain (#4571)

beacon-chain/flags/base.go

@@ -27,6 +27,12 @@ var (
 		Name:  "deposit-contract",
 		Usage: "Deposit contract address. Beacon chain node will listen logs coming from the deposit contract to determine when validator is eligible to participate.",
 	}
+	// RPCHost defines the host on which the RPC server should listen.
+	RPCHost = cli.StringFlag{
+		Name:  "rpc-host",
+		Usage: "Host on which the RPC server should listen",
+		Value: "0.0.0.0",
+	}
 	// RPCPort defines a beacon node RPC port to open.
 	RPCPort = cli.IntFlag{
 		Name:  "rpc-port",

beacon-chain/main.go

@@ -28,6 +28,7 @@ var appFlags = []cli.Flag{
 	flags.DepositContractFlag,
 	flags.Web3ProviderFlag,
 	flags.HTTPWeb3ProviderFlag,
+	flags.RPCHost,
 	flags.RPCPort,
 	flags.CertFlag,
 	flags.KeyFlag,

beacon-chain/node/node.go

@@ -446,6 +446,7 @@ func (b *BeaconNode) registerRPCService(ctx *cli.Context) error {
 		chainStartFetcher = web3Service
 	}
 
+	host := ctx.GlobalString(flags.RPCHost.Name)
 	port := ctx.GlobalString(flags.RPCPort.Name)
 	cert := ctx.GlobalString(flags.CertFlag.Name)
 	key := ctx.GlobalString(flags.KeyFlag.Name)
@@ -454,6 +455,7 @@ func (b *BeaconNode) registerRPCService(ctx *cli.Context) error {
 
 	mockEth1DataVotes := ctx.GlobalBool(flags.InteropMockEth1DataVotesFlag.Name)
 	rpcService := rpc.NewService(context.Background(), &rpc.Config{
+		Host:                  host,
 		Port:                  port,
 		CertFlag:              cert,
 		KeyFlag:               key,

beacon-chain/rpc/service.go

@@ -65,6 +65,7 @@ type Service struct {
 	mockEth1Votes          bool
 	attestationsPool       attestations.Pool
 	syncService            sync.Checker
+	host                   string
 	port                   string
 	listener               net.Listener
 	withCert               string
@@ -88,6 +89,7 @@ type Service struct {
 
 // Config options for the beacon node RPC server.
 type Config struct {
+	Host                  string
 	Port                  string
 	CertFlag              string
 	KeyFlag               string
@@ -136,6 +138,7 @@ func NewService(ctx context.Context, cfg *Config) *Service {
 		mockEth1Votes:         cfg.MockEth1Votes,
 		attestationsPool:      cfg.AttestationsPool,
 		syncService:           cfg.SyncService,
+		host:                  cfg.Host,
 		port:                  cfg.Port,
 		withCert:              cfg.CertFlag,
 		withKey:               cfg.KeyFlag,
@@ -152,12 +155,13 @@ func NewService(ctx context.Context, cfg *Config) *Service {
 
 // Start the gRPC server.
 func (s *Service) Start() {
-	lis, err := net.Listen("tcp", fmt.Sprintf(":%s", s.port))
+	address := fmt.Sprintf("%s:%s", s.host, s.port)
+	lis, err := net.Listen("tcp", address)
 	if err != nil {
-		log.Errorf("Could not listen to port in Start() :%s: %v", s.port, err)
+		log.Errorf("Could not listen to port in Start() %s: %v", address, err)
 	}
 	s.listener = lis
-	log.WithField("port", fmt.Sprintf(":%s", s.port)).Info("RPC-API listening on port")
+	log.WithField("address", address).Info("RPC-API listening on port")
 
 	opts := []grpc.ServerOption{
 		grpc.StatsHandler(&ocgrpc.ServerHandler{}),

beacon-chain/usage.go

@@ -82,6 +82,7 @@ var appHelpFlagGroups = []flagGroup{
 			flags.DepositContractFlag,
 			flags.ContractDeploymentBlock,
 			flags.Web3ProviderFlag,
+			flags.RPCHost,
 			flags.RPCPort,
 			flags.RPCMaxPageSize,
 			flags.CertFlag,