add h2c/http2 support with WithoutCmux option

Signed-off-by: Adphi <philippe.adrien.nousse@gmail.com>

example/example.go

@@ -6,12 +6,14 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"net"
 	"net/http"
 	"strings"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/http2"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/health/grpc_health_v1"
 	"google.golang.org/grpc/metadata"
@@ -130,6 +132,7 @@ func run(opts ...service.Option) {
 			close(done)
 			return nil
 		}),
+		service.WithoutCmux(),
 		service.WithGateway(RegisterGreeterHandler),
 		service.WithGatewayPrefix("/rest"),
 		service.WithGRPCWeb(true),
@@ -242,14 +245,26 @@ func run(opts ...service.Option) {
 		log.Infof("received stream message: %s", m.Message)
 	}
 	scheme := "http://"
+	var (
+		tlsConfig *tls.Config
+		dial      func(ctx context.Context, network, addr string, cfg *tls.Config) (net.Conn, error)
+	)
 	if secure {
 		scheme = "https://"
+		tlsConfig = &tls.Config{
+			InsecureSkipVerify: true,
+		}
+	} else {
+		dial = func(ctx context.Context, network, addr string, cfg *tls.Config) (net.Conn, error) {
+			var d net.Dialer
+			return d.DialContext(ctx, network, addr)
+		}
 	}
 	httpc := &http.Client{
-		Transport: &http.Transport{
-			TLSClientConfig: &tls.Config{
-				InsecureSkipVerify: true,
-			},
+		Transport: &http2.Transport{
+			AllowHTTP:       true,
+			TLSClientConfig: tlsConfig,
+			DialTLSContext:  dial,
 		},
 	}
 	req := `{"name":"test"}`

service/options.go

@@ -334,6 +334,13 @@ func WithReactUI(fs fs.FS, subpath string) Option {
 	}
 }
 
+// WithoutCmux disables the use of cmux for http support to instead use grpc.Server.ServeHTTP method when http support is enabled
+func WithoutCmux() Option {
+	return func(o *options) {
+		o.withoutCmux = true
+	}
+}
+
 type options struct {
 	ctx     context.Context
 	name    string
@@ -381,6 +388,7 @@ type options struct {
 
 	error         error
 	gatewayPrefix string
+	withoutCmux   bool
 }
 
 func (o *options) Name() string {
@@ -499,6 +507,10 @@ func (o *options) GatewayOpts() []runtime.ServeMuxOption {
 	return o.gatewayOpts
 }
 
+func (o *options) WithoutCmux() bool {
+	return o.withoutCmux
+}
+
 func (o *options) parseTLSConfig() error {
 	if o.tlsConfig != nil {
 		return nil

service/service.go

@@ -21,6 +21,8 @@ import (
 	"github.com/rs/cors"
 	"github.com/soheilhy/cmux"
 	"go.uber.org/multierr"
+	"golang.org/x/net/http2"
+	"golang.org/x/net/http2/h2c"
 	"golang.org/x/sync/errgroup"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/health"
@@ -170,12 +172,6 @@ func (s *service) start() (*errgroup.Group, error) {
 		s.opts.address = s.opts.lis.Addr().String()
 	}
 
-	mux := cmux.New(s.opts.lis)
-	mux.SetReadTimeout(5 * time.Second)
-
-	gLis := mux.MatchWithWriters(cmux.HTTP2MatchHeaderFieldSendSettings("content-type", "application/grpc"))
-	hList := mux.Match(cmux.Any())
-
 	for i := range s.opts.beforeStart {
 		if err := s.opts.beforeStart[i](); err != nil {
 			return nil, err
@@ -204,34 +200,23 @@ func (s *service) start() (*errgroup.Group, error) {
 		}
 	}
 
-	g, ctx := errgroup.WithContext(s.opts.ctx)
-	if s.opts.mux != nil {
-		hServer := &http.Server{
-			Handler: alice.New(s.opts.middlewares...).Then(cors.New(s.opts.cors).Handler(s.opts.mux)),
-		}
-		g.Go(func() error {
-			defer hServer.Shutdown(ctx)
-			return hServer.Serve(hList)
-		})
+	fn := s.runWithCmux
+	if s.opts.withoutCmux {
+		fn = s.runWithoutCmux
 	}
 
-	g.Go(func() error {
-		return s.server.Serve(gLis)
-	})
-
-	g.Go(func() error {
-		return ignoreMuxError(mux.Serve())
-	})
+	g, ctx := errgroup.WithContext(s.opts.ctx)
+	if err := fn(ctx, g); err != nil {
+		return nil, err
+	}
 
 	if s.healthServer != nil {
 		for k := range s.services {
 			s.healthServer.SetServingStatus(k, grpc_health_v1.HealthCheckResponse_SERVING)
 		}
 		defer func() {
-			if s.healthServer != nil {
-				for k := range s.services {
-					s.healthServer.SetServingStatus(k, grpc_health_v1.HealthCheckResponse_NOT_SERVING)
-				}
+			for k := range s.services {
+				s.healthServer.SetServingStatus(k, grpc_health_v1.HealthCheckResponse_NOT_SERVING)
 			}
 		}()
 	}
@@ -268,6 +253,63 @@ func (s *service) run() error {
 	}
 }
 
+func (s *service) runWithoutCmux(ctx context.Context, g *errgroup.Group) error {
+	if s.opts.mux != nil {
+		handler := alice.New(s.opts.middlewares...).Then(cors.New(s.opts.cors).Handler(s.opts.mux))
+		hServer := &http.Server{
+			Handler: h2c.NewHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				if r.ProtoMajor == 2 && r.Header.Get("Content-Type") == "application/grpc" {
+					s.server.ServeHTTP(w, r)
+				} else {
+					handler.ServeHTTP(w, r)
+				}
+			}), &http2.Server{}),
+			TLSConfig: s.opts.tlsConfig,
+		}
+		if err := http2.ConfigureServer(hServer, &http2.Server{}); err != nil {
+			return err
+		}
+		g.Go(func() error {
+			defer hServer.Shutdown(ctx)
+			return hServer.Serve(s.opts.lis)
+		})
+	} else {
+		g.Go(func() error {
+			return s.server.Serve(s.opts.lis)
+		})
+	}
+	return nil
+}
+
+func (s *service) runWithCmux(ctx context.Context, g *errgroup.Group) error {
+	mux := cmux.New(s.opts.lis)
+	mux.SetReadTimeout(5 * time.Second)
+
+	gLis := mux.MatchWithWriters(cmux.HTTP2MatchHeaderFieldSendSettings("content-type", "application/grpc"))
+	hList := mux.Match(cmux.Any())
+
+	if s.opts.mux != nil {
+		hServer := &http.Server{
+			Handler:   alice.New(s.opts.middlewares...).Then(cors.New(s.opts.cors).Handler(s.opts.mux)),
+			TLSConfig: s.opts.tlsConfig,
+		}
+		g.Go(func() error {
+			defer hServer.Shutdown(ctx)
+			return hServer.Serve(hList)
+		})
+	}
+
+	g.Go(func() error {
+		return s.server.Serve(gLis)
+	})
+
+	g.Go(func() error {
+		return ignoreMuxError(mux.Serve())
+	})
+
+	return nil
+}
+
 func (s *service) Serve(lis net.Listener) error {
 	s.mu.Lock()
 	s.opts.lis = lis