From 72dd4a18c534453a97ae52b7611d19b8b1f1b363 Mon Sep 17 00:00:00 2001
From: Hitoshi Mitake <h.mitake@gmail.com>
Date: Mon, 31 Dec 2018 19:33:37 +0900
Subject: [PATCH] *: add a new option --enable-grpc-gateway for
 enabling/disabling grpc gateway

---
 embed/config.go      |  3 +++
 embed/etcd.go        |  1 +
 embed/serve.go       | 52 ++++++++++++++++++++++++--------------------
 etcdmain/config.go   |  3 +++
 etcdserver/config.go |  2 ++
 5 files changed, 38 insertions(+), 23 deletions(-)

diff --git a/embed/config.go b/embed/config.go
index d9317b956..01a61f3c9 100644
--- a/embed/config.go
+++ b/embed/config.go
@@ -318,6 +318,9 @@ type Config struct {
 	loggerCore        zapcore.Core
 	loggerWriteSyncer zapcore.WriteSyncer
 
+	// EnableGRPCGateway is false to disable grpc gateway.
+	EnableGRPCGateway bool `json:"enable-grpc-gateway"`
+
 	// TO BE DEPRECATED
 
 	// LogPkgLevels is being deprecated in v3.5.
diff --git a/embed/etcd.go b/embed/etcd.go
index d61692a3a..7cfce805b 100644
--- a/embed/etcd.go
+++ b/embed/etcd.go
@@ -200,6 +200,7 @@ func StartEtcd(inCfg *Config) (e *Etcd, err error) {
 		LoggerWriteSyncer:          cfg.loggerWriteSyncer,
 		Debug:                      cfg.Debug,
 		ForceNewCluster:            cfg.ForceNewCluster,
+		EnableGRPCGateway:          cfg.EnableGRPCGateway,
 	}
 	print(e.cfg.logger, *cfg, srvcfg, memberInitialized)
 	if e.Server, err = etcdserver.NewServer(srvcfg); err != nil {
diff --git a/embed/serve.go b/embed/serve.go
index af82dbe50..7cbcc9e57 100644
--- a/embed/serve.go
+++ b/embed/serve.go
@@ -118,9 +118,11 @@ func (sctx *serveCtx) serve(
 		go func() { errHandler(gs.Serve(grpcl)) }()
 
 		var gwmux *gw.ServeMux
-		gwmux, err = sctx.registerGateway([]grpc.DialOption{grpc.WithInsecure()})
-		if err != nil {
-			return err
+		if s.Cfg.EnableGRPCGateway {
+			gwmux, err = sctx.registerGateway([]grpc.DialOption{grpc.WithInsecure()})
+			if err != nil {
+				return err
+			}
 		}
 
 		httpmux := sctx.createMux(gwmux, handler)
@@ -156,15 +158,17 @@ func (sctx *serveCtx) serve(
 		}
 		handler = grpcHandlerFunc(gs, handler)
 
-		dtls := tlscfg.Clone()
-		// trust local server
-		dtls.InsecureSkipVerify = true
-		creds := credentials.NewTLS(dtls)
-		opts := []grpc.DialOption{grpc.WithTransportCredentials(creds)}
 		var gwmux *gw.ServeMux
-		gwmux, err = sctx.registerGateway(opts)
-		if err != nil {
-			return err
+		if s.Cfg.EnableGRPCGateway {
+			dtls := tlscfg.Clone()
+			// trust local server
+			dtls.InsecureSkipVerify = true
+			creds := credentials.NewTLS(dtls)
+			opts := []grpc.DialOption{grpc.WithTransportCredentials(creds)}
+			gwmux, err = sctx.registerGateway(opts)
+			if err != nil {
+				return err
+			}
 		}
 
 		var tlsl net.Listener
@@ -270,19 +274,21 @@ func (sctx *serveCtx) createMux(gwmux *gw.ServeMux, handler http.Handler) *http.
 		httpmux.Handle(path, h)
 	}
 
-	httpmux.Handle(
-		"/v3/",
-		wsproxy.WebsocketProxy(
-			gwmux,
-			wsproxy.WithRequestMutator(
-				// Default to the POST method for streams
-				func(_ *http.Request, outgoing *http.Request) *http.Request {
-					outgoing.Method = "POST"
-					return outgoing
-				},
+	if gwmux != nil {
+		httpmux.Handle(
+			"/v3/",
+			wsproxy.WebsocketProxy(
+				gwmux,
+				wsproxy.WithRequestMutator(
+					// Default to the POST method for streams
+					func(_ *http.Request, outgoing *http.Request) *http.Request {
+						outgoing.Method = "POST"
+						return outgoing
+					},
+				),
 			),
-		),
-	)
+		)
+	}
 	if handler != nil {
 		httpmux.Handle("/", handler)
 	}
diff --git a/etcdmain/config.go b/etcdmain/config.go
index 78700e74d..db5ece034 100644
--- a/etcdmain/config.go
+++ b/etcdmain/config.go
@@ -241,6 +241,9 @@ func newConfig() *config {
 	fs.StringVar(&cfg.ec.AuthToken, "auth-token", cfg.ec.AuthToken, "Specify auth token specific options.")
 	fs.UintVar(&cfg.ec.BcryptCost, "bcrypt-cost", cfg.ec.BcryptCost, "Specify bcrypt algorithm cost factor for auth password hashing.")
 
+	// gateway
+	fs.BoolVar(&cfg.ec.EnableGRPCGateway, "enable-grpc-gateway", true, "Enable GRPC gateway.")
+
 	// experimental
 	fs.BoolVar(&cfg.ec.ExperimentalInitialCorruptCheck, "experimental-initial-corrupt-check", cfg.ec.ExperimentalInitialCorruptCheck, "Enable to check data corruption before serving any client/peer traffic.")
 	fs.DurationVar(&cfg.ec.ExperimentalCorruptCheckTime, "experimental-corrupt-check-time", cfg.ec.ExperimentalCorruptCheckTime, "Duration of time between cluster corruption check passes.")
diff --git a/etcdserver/config.go b/etcdserver/config.go
index 5bf10ea4d..d037b83b9 100644
--- a/etcdserver/config.go
+++ b/etcdserver/config.go
@@ -148,6 +148,8 @@ type ServerConfig struct {
 
 	// LeaseCheckpointInterval time.Duration is the wait duration between lease checkpoints.
 	LeaseCheckpointInterval time.Duration
+
+	EnableGRPCGateway bool
 }
 
 // VerifyBootstrap sanity-checks the initial config for bootstrap case