http2 without tls (h2c)

dgraph/cmd/alpha/run.go

@@ -41,6 +41,8 @@ import (
 	"go.opencensus.io/plugin/ocgrpc"
 	otrace "go.opencensus.io/trace"
 	"go.opencensus.io/zpages"
+	"golang.org/x/net/http2"
+	"golang.org/x/net/http2/h2c"
 	"golang.org/x/net/trace"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
@@ -573,6 +575,7 @@ func setupServer(closer *z.Closer) {
 	baseMux.Handle("/", http.HandlerFunc(homeHandler))
 	baseMux.Handle("/ui/keywords", http.HandlerFunc(keywordHandler))
 
+	x.H2cHandler = h2c.NewHandler(baseMux, &http2.Server{})
 	// Initialize the servers.
 	x.ServerCloser.AddRunning(3)
 	go serveGRPC(grpcListener, tlsCfg, x.ServerCloser)

dgraph/cmd/zero/run.go

@@ -34,6 +34,8 @@ import (
 	"go.opencensus.io/plugin/ocgrpc"
 	otrace "go.opencensus.io/trace"
 	"go.opencensus.io/zpages"
+	"golang.org/x/net/http2"
+	"golang.org/x/net/http2/h2c"
 	"golang.org/x/net/trace"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
@@ -316,7 +318,6 @@ func run() {
 
 	tlsCfg, err := x.LoadServerTLSConfig(Zero.Conf)
 	x.Check(err)
-	go x.StartListenHttpAndHttps(httpListener, tlsCfg, st.zero.closer)
 
 	baseMux := http.NewServeMux()
 	http.Handle("/", audit.AuditRequestHttp(baseMux))
@@ -333,6 +334,10 @@ func run() {
 	baseMux.HandleFunc("/debug/jemalloc", x.JemallocHandler)
 	zpages.Handle(baseMux, "/debug/z")
 
+	x.H2cHandler = h2c.NewHandler(baseMux, &http2.Server{})
+
+	go x.StartListenHttpAndHttps(httpListener, tlsCfg, st.zero.closer)
+
 	// This must be here. It does not work if placed before Grpc init.
 	x.Check(st.node.initAndStartNode())
 

x/server.go

@@ -60,8 +60,11 @@ func startServers(m cmux.CMux, tlsConf *tls.Config) {
 	}
 }
 
+var H2cHandler http.Handler
+
 func startListen(l net.Listener) {
 	srv := &http.Server{
+		Handler:           H2cHandler,
 		ReadTimeout:       10 * time.Second,
 		WriteTimeout:      600 * time.Second,
 		IdleTimeout:       2 * time.Minute,