// This is an example for serving HTTP, HTTPS, and GoRPC/TLS on the same port.
func Example_recursiveCmux() {
	// Create the TCP listener.
	l, err := net.Listen("tcp", "127.0.0.1:50051")
	if err != nil {
		log.Panic(err)
	}

	// Create a mux.
	tcpm := cmux.New(l)

	// We first match on HTTP 1.1 methods.
	httpl := tcpm.Match(cmux.HTTP1Fast())

	// If not matched, we assume that its TLS.
	tlsl := tcpm.Match(cmux.Any())
	tlsl = tlsListener(tlsl)

	// Now, we build another mux recursively to match HTTPS and GoRPC.
	// You can use the same trick for SSH.
	tlsm := cmux.New(tlsl)
	httpsl := tlsm.Match(cmux.HTTP1Fast())
	gorpcl := tlsm.Match(cmux.Any())
	go recursiveServeHTTP(httpl)
	go recursiveServeHTTP(httpsl)
	go recursiveServeRPC(gorpcl)

	go func() {
		if err := tlsm.Serve(); err != cmux.ErrListenerClosed {
			panic(err)
		}
	}()
	if err := tcpm.Serve(); !strings.Contains(err.Error(), "use of closed network connection") {
		panic(err)
	}
}

// This is an example for serving HTTP and HTTPS on the same port.
func Example_bothHTTPAndHTTPS() {
	// Create the TCP listener.
	l, err := net.Listen("tcp", "127.0.0.1:50051")
	if err != nil {
		log.Panic(err)
	}

	// Create a mux.
	m := cmux.New(l)

	// We first match on HTTP 1.1 methods.
	httpl := m.Match(cmux.HTTP1Fast())

	// If not matched, we assume that its TLS.
	//
	// Note that you can take this listener, do TLS handshake and
	// create another mux to multiplex the connections over TLS.
	tlsl := m.Match(cmux.Any())

	go serveHTTP1(httpl)
	go serveHTTPS(tlsl)

	if err := m.Serve(); !strings.Contains(err.Error(), "use of closed network connection") {
		panic(err)
	}
}

func Example() {
	l, err := net.Listen("tcp", "127.0.0.1:50051")
	if err != nil {
		log.Panic(err)
	}

	m := cmux.New(l)

	// We first match the connection against HTTP2 fields. If matched, the
	// connection will be sent through the "grpcl" listener.
	grpcl := m.Match(cmux.HTTP2HeaderField("content-type", "application/grpc"))
	//Otherwise, we match it againts a websocket upgrade request.
	wsl := m.Match(cmux.HTTP1HeaderField("Upgrade", "websocket"))

	// Otherwise, we match it againts HTTP1 methods. If matched,
	// it is sent through the "httpl" listener.
	httpl := m.Match(cmux.HTTP1Fast())
	// If not matched by HTTP, we assume it is an RPC connection.
	rpcl := m.Match(cmux.Any())

	// Then we used the muxed listeners.
	go serveGRPC(grpcl)
	go serveWS(wsl)
	go serveHTTP(httpl)
	go serveRPC(rpcl)

	if err := m.Serve(); !strings.Contains(err.Error(), "use of closed network connection") {
		panic(err)
	}
}

// ListenAndServe creates a listener and serves handler on it, closing the
// listener when signalled by the stopper. The handling server implements HTTP1
// and HTTP2, with or without TLS. Note that the "real" server also implements
// the postgres wire protocol, and so does not use this function, but the
// pattern used is similar; that implementation is in server/server.go.
func ListenAndServe(stopper *stop.Stopper, handler http.Handler, addr net.Addr, tlsConfig *tls.Config) (net.Listener, error) {
	ln, err := net.Listen(addr.Network(), addr.String())
	if err != nil {
		return ln, err
	}
	stopper.RunWorker(func() {
		<-stopper.ShouldDrain()
		// Some unit tests manually close `ln`, so it may already be closed
		// when we get here.
		FatalIfUnexpected(ln.Close())
	})

	if tlsConfig != nil {
		// We're in TLS mode. ALPN will be used to automatically handle HTTP1 and
		// HTTP2 requests.
		ServeHandler(stopper, handler, tls.NewListener(ln, tlsConfig), tlsConfig)
	} else {
		// We're not in TLS mode. We're going to implement h2c (HTTP2 Clear Text)
		// ourselves.

		m := cmux.New(ln)
		// HTTP2 connections are easy to identify because they have a common
		// preface.
		h2L := m.Match(cmux.HTTP2())
		// All other connections will get the default treatment.
		anyL := m.Match(cmux.Any())

		// Construct our h2c handler function.
		var h2 http2.Server
		serveConnOpts := &http2.ServeConnOpts{
			Handler: handler,
		}
		serveH2 := func(conn net.Conn) {
			h2.ServeConn(conn, serveConnOpts)
		}

		// Start serving HTTP1 on all non-HTTP2 connections.
		serveConn := ServeHandler(stopper, handler, anyL, tlsConfig)

		// Start serving h2c on all HTTP2 connections.
		stopper.RunWorker(func() {
			FatalIfUnexpected(serveConn(h2L, serveH2))
		})

		// Finally start the multiplexing listener.
		stopper.RunWorker(func() {
			FatalIfUnexpected(m.Serve())
		})
	}
	return ln, nil
}

// serve accepts incoming connections on the listener l,
// creating a new service goroutine for each. The service goroutines
// read requests and then call handler to reply to them.
func serve(sctx *serveCtx, s *etcdserver.EtcdServer, tlscfg *tls.Config, handler http.Handler) error {
	logger := defaultLog.New(ioutil.Discard, "etcdhttp", 0)

	<-s.ReadyNotify()
	plog.Info("ready to serve client requests")

	m := cmux.New(sctx.l)

	if sctx.insecure {
		gs := v3rpc.Server(s, nil)
		grpcl := m.Match(cmux.HTTP2())
		go func() { plog.Fatal(gs.Serve(grpcl)) }()

		srvhttp := &http.Server{
			Handler:  handler,
			ErrorLog: logger, // do not log user error
		}
		httpl := m.Match(cmux.HTTP1())
		go func() { plog.Fatal(srvhttp.Serve(httpl)) }()
		plog.Noticef("serving insecure client requests on %s, this is strongly discouraged!", sctx.host)
	}

	if sctx.secure {
		gs := v3rpc.Server(s, tlscfg)
		handler = grpcHandlerFunc(gs, handler)

		tlsl := tls.NewListener(m.Match(cmux.Any()), tlscfg)
		// TODO: add debug flag; enable logging when debug flag is set
		srv := &http.Server{
			Handler:   handler,
			TLSConfig: tlscfg,
			ErrorLog:  logger, // do not log user error
		}
		go func() { plog.Fatal(srv.Serve(tlsl)) }()

		plog.Infof("serving client requests on %s", sctx.host)
	}

	return m.Serve()
}

// serve accepts incoming connections on the listener l,
// creating a new service goroutine for each. The service goroutines
// read requests and then call handler to reply to them.
func serve(sctx *serveCtx, s *etcdserver.EtcdServer, tlscfg *tls.Config, handler http.Handler) error {
	logger := defaultLog.New(ioutil.Discard, "etcdhttp", 0)

	<-s.ReadyNotify()
	plog.Info("ready to serve client requests")

	m := cmux.New(sctx.l)

	if sctx.insecure {
		gs := v3rpc.Server(s, nil)
		grpcl := m.Match(cmux.HTTP2())
		go func() { plog.Fatal(gs.Serve(grpcl)) }()

		opts := []grpc.DialOption{
			grpc.WithInsecure(),
		}
		gwmux, err := registerGateway(sctx.l.Addr().String(), opts)
		if err != nil {
			return err
		}

		httpmux := http.NewServeMux()
		httpmux.Handle("/v3alpha/", gwmux)
		httpmux.Handle("/", handler)
		srvhttp := &http.Server{
			Handler:  httpmux,
			ErrorLog: logger, // do not log user error
		}
		httpl := m.Match(cmux.HTTP1())
		go func() { plog.Fatal(srvhttp.Serve(httpl)) }()
		plog.Noticef("serving insecure client requests on %s, this is strongly discouraged!", sctx.host)
	}

	if sctx.secure {
		gs := v3rpc.Server(s, tlscfg)
		handler = grpcHandlerFunc(gs, handler)

		dtls := *tlscfg
		// trust local server
		dtls.InsecureSkipVerify = true
		creds := credentials.NewTLS(&dtls)
		opts := []grpc.DialOption{grpc.WithTransportCredentials(creds)}
		gwmux, err := registerGateway(sctx.l.Addr().String(), opts)
		if err != nil {
			return err
		}

		tlsl := tls.NewListener(m.Match(cmux.Any()), tlscfg)
		// TODO: add debug flag; enable logging when debug flag is set
		httpmux := http.NewServeMux()
		httpmux.Handle("/v3alpha/", gwmux)
		httpmux.Handle("/", handler)
		srv := &http.Server{
			Handler:   httpmux,
			TLSConfig: tlscfg,
			ErrorLog:  logger, // do not log user error
		}
		go func() { plog.Fatal(srv.Serve(tlsl)) }()

		plog.Infof("serving client requests on %s", sctx.host)
	}

	return m.Serve()
}

// Start starts the server on the specified port, starts gossip and
// initializes the node using the engines from the server's context.
func (s *Server) Start() error {
	s.initHTTP()

	tlsConfig, err := s.ctx.GetServerTLSConfig()
	if err != nil {
		return err
	}

	// The following code is a specialization of util/net.go's ListenAndServe
	// which adds pgwire support. A single port is used to serve all protocols
	// (pg, http, h2) via the following construction:
	//
	// non-TLS case:
	// net.Listen -> cmux.New -> pgwire.Match -> pgwire.Server.ServeConn
	//               |
	//               -  -> cmux.HTTP2 -> http2.(*Server).ServeConn
	//               -  -> cmux.Any -> http.(*Server).Serve
	//
	// TLS case:
	// net.Listen -> cmux.New -> pgwire.Match -> pgwire.Server.ServeConn
	//               |
	//               -  -> cmux.Any -> tls.NewListener -> http.(*Server).Serve
	//
	// Note that the difference between the TLS and non-TLS cases exists due to
	// Go's lack of an h2c (HTTP2 Clear Text) implementation. See inline comments
	// in util.ListenAndServe for an explanation of how h2c is implemented there
	// and here.

	ln, err := net.Listen("tcp", s.ctx.Addr)
	if err != nil {
		return err
	}
	unresolvedAddr, err := officialAddr(s.ctx.Addr, ln.Addr())
	if err != nil {
		return err
	}
	s.ctx.Addr = unresolvedAddr.String()

	s.stopper.RunWorker(func() {
		<-s.stopper.ShouldDrain()
		if err := ln.Close(); err != nil {
			log.Fatal(err)
		}
	})

	m := cmux.New(ln)
	pgL := m.Match(pgwire.Match)

	var serveConn func(net.Listener, func(net.Conn)) error
	if tlsConfig != nil {
		anyL := m.Match(cmux.Any())
		serveConn = util.ServeHandler(s.stopper, s, tls.NewListener(anyL, tlsConfig), tlsConfig)
	} else {
		h2L := m.Match(cmux.HTTP2())
		anyL := m.Match(cmux.Any())

		var h2 http2.Server
		serveConnOpts := &http2.ServeConnOpts{
			Handler: s,
		}
		serveH2 := func(conn net.Conn) {
			h2.ServeConn(conn, serveConnOpts)
		}

		serveConn = util.ServeHandler(s.stopper, s, anyL, tlsConfig)

		s.stopper.RunWorker(func() {
			util.FatalIfUnexpected(serveConn(h2L, serveH2))
		})
	}

	s.stopper.RunWorker(func() {
		util.FatalIfUnexpected(serveConn(pgL, func(conn net.Conn) {
			if err := s.pgServer.ServeConn(conn); err != nil && !util.IsClosedConnection(err) {
				log.Error(err)
			}
		}))
	})

	s.stopper.RunWorker(func() {
		util.FatalIfUnexpected(m.Serve())
	})

	s.rpcContext.SetLocalServer(s.rpc, s.ctx.Addr)

	s.gossip.Start(s.grpc, unresolvedAddr)

	if err := s.node.start(s.rpc, unresolvedAddr, s.ctx.Engines, s.ctx.NodeAttributes); err != nil {
		return err
	}

	// Begin recording runtime statistics.
	runtime := status.NewRuntimeStatRecorder(s.node.Descriptor.NodeID, s.clock)
	s.tsDB.PollSource(runtime, s.ctx.MetricsFrequency, ts.Resolution10s, s.stopper)

	// Begin recording time series data collected by the status monitor.
	s.tsDB.PollSource(s.recorder, s.ctx.MetricsFrequency, ts.Resolution10s, s.stopper)

//.........这里部分代码省略.........

// Start starts the server on the specified port, starts gossip and
// initializes the node using the engines from the server's context.
func (s *Server) Start() error {
	s.initHTTP()

	tlsConfig, err := s.ctx.GetServerTLSConfig()
	if err != nil {
		return err
	}

	// The following code is a specialization of util/net.go's ListenAndServe
	// which adds pgwire support. A single port is used to serve all protocols
	// (pg, http, h2) via the following construction:
	//
	// non-TLS case:
	// net.Listen -> cmux.New
	//               |
	//               -  -> pgwire.Match -> pgwire.Server.ServeConn
	//               -  -> cmux.Any -> grpc.(*Server).Serve
	//
	// TLS case:
	// net.Listen -> cmux.New
	//               |
	//               -  -> pgwire.Match -> pgwire.Server.ServeConn
	//               -  -> cmux.Any -> grpc.(*Server).Serve
	//
	// Note that the difference between the TLS and non-TLS cases exists due to
	// Go's lack of an h2c (HTTP2 Clear Text) implementation. See inline comments
	// in util.ListenAndServe for an explanation of how h2c is implemented there
	// and here.

	ln, err := net.Listen("tcp", s.ctx.Addr)
	if err != nil {
		return err
	}
	unresolvedAddr, err := officialAddr(s.ctx.Addr, ln.Addr())
	if err != nil {
		return err
	}
	s.ctx.Addr = unresolvedAddr.String()
	s.rpcContext.SetLocalInternalServer(s.node, s.ctx.Addr)

	s.stopper.RunWorker(func() {
		<-s.stopper.ShouldDrain()
		if err := ln.Close(); err != nil {
			log.Fatal(err)
		}
	})

	m := cmux.New(ln)
	pgL := m.Match(pgwire.Match)
	anyL := m.Match(cmux.Any())

	httpLn, err := net.Listen("tcp", s.ctx.HTTPAddr)
	if err != nil {
		return err
	}
	unresolvedHTTPAddr, err := officialAddr(s.ctx.HTTPAddr, httpLn.Addr())
	if err != nil {
		return err
	}
	s.ctx.HTTPAddr = unresolvedHTTPAddr.String()

	s.stopper.RunWorker(func() {
		<-s.stopper.ShouldDrain()
		if err := httpLn.Close(); err != nil {
			log.Fatal(err)
		}
	})

	if tlsConfig != nil {
		httpMux := cmux.New(httpLn)
		clearL := httpMux.Match(cmux.HTTP1Fast())
		tlsL := httpMux.Match(cmux.Any())

		s.stopper.RunWorker(func() {
			util.FatalIfUnexpected(httpMux.Serve())
		})

		util.ServeHandler(s.stopper, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// TODO(tamird): s/308/http.StatusPermanentRedirect/ when it exists.
			http.Redirect(w, r, "https://"+r.Host+r.RequestURI, 308)
		}), clearL, tlsConfig)

		httpLn = tls.NewListener(tlsL, tlsConfig)
	}

	serveConn := util.ServeHandler(s.stopper, s, httpLn, tlsConfig)

	s.stopper.RunWorker(func() {
		util.FatalIfUnexpected(s.grpc.Serve(anyL))
	})

	s.stopper.RunWorker(func() {
		util.FatalIfUnexpected(serveConn(pgL, func(conn net.Conn) {
			if err := s.pgServer.ServeConn(conn); err != nil && !util.IsClosedConnection(err) {
				log.Error(err)
			}
		}))
	})
//.........这里部分代码省略.........

// Start starts the server on the specified port, starts gossip and initializes
// the node using the engines from the server's context.
//
// The passed context can be used to trace the server startup. The context
// should represent the general startup operation.
func (s *Server) Start(ctx context.Context) error {
	ctx = s.AnnotateCtx(ctx)

	startTime := timeutil.Now()

	tlsConfig, err := s.cfg.GetServerTLSConfig()
	if err != nil {
		return err
	}

	httpServer := netutil.MakeServer(s.stopper, tlsConfig, s)
	plainRedirectServer := netutil.MakeServer(s.stopper, tlsConfig, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Redirect(w, r, "https://"+r.Host+r.RequestURI, http.StatusPermanentRedirect)
	}))

	// The following code is a specialization of util/net.go's ListenAndServe
	// which adds pgwire support. A single port is used to serve all protocols
	// (pg, http, h2) via the following construction:
	//
	// non-TLS case:
	// net.Listen -> cmux.New
	//               |
	//               -  -> pgwire.Match -> pgwire.Server.ServeConn
	//               -  -> cmux.Any -> grpc.(*Server).Serve
	//
	// TLS case:
	// net.Listen -> cmux.New
	//               |
	//               -  -> pgwire.Match -> pgwire.Server.ServeConn
	//               -  -> cmux.Any -> grpc.(*Server).Serve
	//
	// Note that the difference between the TLS and non-TLS cases exists due to
	// Go's lack of an h2c (HTTP2 Clear Text) implementation. See inline comments
	// in util.ListenAndServe for an explanation of how h2c is implemented there
	// and here.

	ln, err := net.Listen("tcp", s.cfg.Addr)
	if err != nil {
		return err
	}
	log.Eventf(ctx, "listening on port %s", s.cfg.Addr)
	unresolvedListenAddr, err := officialAddr(s.cfg.Addr, ln.Addr())
	if err != nil {
		return err
	}
	s.cfg.Addr = unresolvedListenAddr.String()
	unresolvedAdvertAddr, err := officialAddr(s.cfg.AdvertiseAddr, ln.Addr())
	if err != nil {
		return err
	}
	s.cfg.AdvertiseAddr = unresolvedAdvertAddr.String()

	s.rpcContext.SetLocalInternalServer(s.node)

	m := cmux.New(ln)
	pgL := m.Match(pgwire.Match)
	anyL := m.Match(cmux.Any())

	httpLn, err := net.Listen("tcp", s.cfg.HTTPAddr)
	if err != nil {
		return err
	}
	unresolvedHTTPAddr, err := officialAddr(s.cfg.HTTPAddr, httpLn.Addr())
	if err != nil {
		return err
	}
	s.cfg.HTTPAddr = unresolvedHTTPAddr.String()

	workersCtx := s.AnnotateCtx(context.Background())

	s.stopper.RunWorker(func() {
		<-s.stopper.ShouldQuiesce()
		if err := httpLn.Close(); err != nil {
			log.Fatal(workersCtx, err)
		}
	})

	if tlsConfig != nil {
		httpMux := cmux.New(httpLn)
		clearL := httpMux.Match(cmux.HTTP1())
		tlsL := httpMux.Match(cmux.Any())

		s.stopper.RunWorker(func() {
			netutil.FatalIfUnexpected(httpMux.Serve())
		})

		s.stopper.RunWorker(func() {
			netutil.FatalIfUnexpected(plainRedirectServer.Serve(clearL))
		})

		httpLn = tls.NewListener(tlsL, tlsConfig)
	}

	s.stopper.RunWorker(func() {
		netutil.FatalIfUnexpected(httpServer.Serve(httpLn))
//.........这里部分代码省略.........

// Start starts the server on the specified port, starts gossip and initializes
// the node using the engines from the server's context.
//
// The passed context can be used to trace the server startup. The context
// should represent the general startup operation, and is different from
// contexts used at runtime for server's background work (like `s.Ctx()`).
func (s *Server) Start(ctx context.Context) error {
	// Copy log tags from s.Ctx()
	ctx = log.WithLogTagsFromCtx(ctx, s.Ctx())

	tlsConfig, err := s.ctx.GetServerTLSConfig()
	if err != nil {
		return err
	}

	httpServer := netutil.MakeServer(s.stopper, tlsConfig, s)
	plainRedirectServer := netutil.MakeServer(s.stopper, tlsConfig, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Redirect(w, r, "https://"+r.Host+r.RequestURI, http.StatusPermanentRedirect)
	}))

	// The following code is a specialization of util/net.go's ListenAndServe
	// which adds pgwire support. A single port is used to serve all protocols
	// (pg, http, h2) via the following construction:
	//
	// non-TLS case:
	// net.Listen -> cmux.New
	//               |
	//               -  -> pgwire.Match -> pgwire.Server.ServeConn
	//               -  -> cmux.Any -> grpc.(*Server).Serve
	//
	// TLS case:
	// net.Listen -> cmux.New
	//               |
	//               -  -> pgwire.Match -> pgwire.Server.ServeConn
	//               -  -> cmux.Any -> grpc.(*Server).Serve
	//
	// Note that the difference between the TLS and non-TLS cases exists due to
	// Go's lack of an h2c (HTTP2 Clear Text) implementation. See inline comments
	// in util.ListenAndServe for an explanation of how h2c is implemented there
	// and here.

	ln, err := net.Listen("tcp", s.ctx.Addr)
	if err != nil {
		return err
	}
	log.Tracef(ctx, "listening on port %s", s.ctx.Addr)
	unresolvedAddr, err := officialAddr(s.ctx.Addr, ln.Addr())
	if err != nil {
		return err
	}
	s.ctx.Addr = unresolvedAddr.String()
	s.rpcContext.SetLocalInternalServer(s.node)

	m := cmux.New(ln)
	pgL := m.Match(pgwire.Match)
	anyL := m.Match(cmux.Any())

	httpLn, err := net.Listen("tcp", s.ctx.HTTPAddr)
	if err != nil {
		return err
	}
	unresolvedHTTPAddr, err := officialAddr(s.ctx.HTTPAddr, httpLn.Addr())
	if err != nil {
		return err
	}
	s.ctx.HTTPAddr = unresolvedHTTPAddr.String()

	s.stopper.RunWorker(func() {
		<-s.stopper.ShouldQuiesce()
		if err := httpLn.Close(); err != nil {
			log.Fatal(s.Ctx(), err)
		}
	})

	if tlsConfig != nil {
		httpMux := cmux.New(httpLn)
		clearL := httpMux.Match(cmux.HTTP1())
		tlsL := httpMux.Match(cmux.Any())

		s.stopper.RunWorker(func() {
			netutil.FatalIfUnexpected(httpMux.Serve())
		})

		s.stopper.RunWorker(func() {
			netutil.FatalIfUnexpected(plainRedirectServer.Serve(clearL))
		})

		httpLn = tls.NewListener(tlsL, tlsConfig)
	}

	s.stopper.RunWorker(func() {
		netutil.FatalIfUnexpected(httpServer.Serve(httpLn))
	})

	s.stopper.RunWorker(func() {
		<-s.stopper.ShouldQuiesce()
		netutil.FatalIfUnexpected(anyL.Close())
		<-s.stopper.ShouldStop()
		s.grpc.Stop()
	})
//.........这里部分代码省略.........

// Start starts the server on the specified port, starts gossip and
// initializes the node using the engines from the server's context.
func (s *Server) Start() error {
	tlsConfig, err := s.ctx.GetServerTLSConfig()
	if err != nil {
		return err
	}

	httpServer := netutil.MakeServer(s.stopper, tlsConfig, s)
	plainRedirectServer := netutil.MakeServer(s.stopper, tlsConfig, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// TODO(tamird): s/308/http.StatusPermanentRedirect/ when it exists.
		http.Redirect(w, r, "https://"+r.Host+r.RequestURI, 308)
	}))

	// The following code is a specialization of util/net.go's ListenAndServe
	// which adds pgwire support. A single port is used to serve all protocols
	// (pg, http, h2) via the following construction:
	//
	// non-TLS case:
	// net.Listen -> cmux.New
	//               |
	//               -  -> pgwire.Match -> pgwire.Server.ServeConn
	//               -  -> cmux.Any -> grpc.(*Server).Serve
	//
	// TLS case:
	// net.Listen -> cmux.New
	//               |
	//               -  -> pgwire.Match -> pgwire.Server.ServeConn
	//               -  -> cmux.Any -> grpc.(*Server).Serve
	//
	// Note that the difference between the TLS and non-TLS cases exists due to
	// Go's lack of an h2c (HTTP2 Clear Text) implementation. See inline comments
	// in util.ListenAndServe for an explanation of how h2c is implemented there
	// and here.

	ln, err := net.Listen("tcp", s.ctx.Addr)
	if err != nil {
		return err
	}
	unresolvedAddr, err := officialAddr(s.ctx.Addr, ln.Addr())
	if err != nil {
		return err
	}
	s.ctx.Addr = unresolvedAddr.String()
	s.rpcContext.SetLocalInternalServer(s.node)

	s.stopper.RunWorker(func() {
		<-s.stopper.ShouldQuiesce()
		if err := ln.Close(); err != nil {
			log.Fatal(err)
		}
	})

	m := cmux.New(ln)
	pgL := m.Match(pgwire.Match)
	anyL := m.Match(cmux.Any())

	httpLn, err := net.Listen("tcp", s.ctx.HTTPAddr)
	if err != nil {
		return err
	}
	unresolvedHTTPAddr, err := officialAddr(s.ctx.HTTPAddr, httpLn.Addr())
	if err != nil {
		return err
	}
	s.ctx.HTTPAddr = unresolvedHTTPAddr.String()

	s.stopper.RunWorker(func() {
		<-s.stopper.ShouldQuiesce()
		if err := httpLn.Close(); err != nil {
			log.Fatal(err)
		}
	})

	if tlsConfig != nil {
		httpMux := cmux.New(httpLn)
		clearL := httpMux.Match(cmux.HTTP1())
		tlsL := httpMux.Match(cmux.Any())

		s.stopper.RunWorker(func() {
			netutil.FatalIfUnexpected(httpMux.Serve())
		})

		s.stopper.RunWorker(func() {
			netutil.FatalIfUnexpected(plainRedirectServer.Serve(clearL))
		})

		httpLn = tls.NewListener(tlsL, tlsConfig)
	}

	s.stopper.RunWorker(func() {
		netutil.FatalIfUnexpected(httpServer.Serve(httpLn))
	})

	s.stopper.RunWorker(func() {
		netutil.FatalIfUnexpected(s.grpc.Serve(anyL))
	})

	s.stopper.RunWorker(func() {
		netutil.FatalIfUnexpected(httpServer.ServeWith(pgL, func(conn net.Conn) {
//.........这里部分代码省略.........

func startGRPCProxy(cmd *cobra.Command, args []string) {
	l, err := net.Listen("tcp", grpcProxyListenAddr)
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
	if l, err = transport.NewKeepAliveListener(l, "tcp", nil); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
	plog.Infof("listening for grpc-proxy client requests on %s", grpcProxyListenAddr)
	defer func() {
		l.Close()
		plog.Infof("stopping listening for grpc-proxy client requests on %s", grpcProxyListenAddr)
	}()
	m := cmux.New(l)

	cfg, err := newClientCfg()
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}

	client, err := clientv3.New(*cfg)
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}

	kvp := grpcproxy.NewKvProxy(client)
	watchp := grpcproxy.NewWatchProxy(client)
	clusterp := grpcproxy.NewClusterProxy(client)
	leasep := grpcproxy.NewLeaseProxy(client)
	mainp := grpcproxy.NewMaintenanceProxy(client)
	authp := grpcproxy.NewAuthProxy(client)

	server := grpc.NewServer(
		grpc.StreamInterceptor(grpc_prometheus.StreamServerInterceptor),
		grpc.UnaryInterceptor(grpc_prometheus.UnaryServerInterceptor),
	)
	pb.RegisterKVServer(server, kvp)
	pb.RegisterWatchServer(server, watchp)
	pb.RegisterClusterServer(server, clusterp)
	pb.RegisterLeaseServer(server, leasep)
	pb.RegisterMaintenanceServer(server, mainp)
	pb.RegisterAuthServer(server, authp)

	errc := make(chan error)

	grpcl := m.Match(cmux.HTTP2())
	go func() { errc <- server.Serve(grpcl) }()

	httpmux := http.NewServeMux()
	httpmux.HandleFunc("/", http.NotFound)
	httpmux.Handle("/metrics", prometheus.Handler())
	srvhttp := &http.Server{
		Handler: httpmux,
	}

	var httpl net.Listener
	if cfg.TLS != nil {
		srvhttp.TLSConfig = cfg.TLS
		httpl = tls.NewListener(m.Match(cmux.Any()), cfg.TLS)
	} else {
		httpl = m.Match(cmux.HTTP1())
	}
	go func() { errc <- srvhttp.Serve(httpl) }()

	go func() { errc <- m.Serve() }()

	fmt.Fprintln(os.Stderr, <-errc)
	os.Exit(1)
}