TT-968 enabled h2c by default (TykTechnologies#3380)

* fix grpc proxy connection

* clean and format code

* clean code

* remove h2c config from gateway config

* replace h2c protocol from url and set it as http

* removed config enable_h2c at api level and infer it from the target url which should contains h2c://

* update grpc test

* gofmt gw file

* enabled h2c by default to http servers

* remove duplicated registeering of healthcheck

Co-authored-by: tbuchaillot <[email protected]>

gateway/api_loader.go

@@ -119,6 +119,7 @@ func processSpec(spec *APISpec, apisByListen map[string]int,
 		"prefix": "coprocess",
 	})
 
+
 	if strings.Contains(spec.Proxy.TargetURL, "h2c://") {
 		spec.Proxy.TargetURL = strings.Replace(spec.Proxy.TargetURL, "h2c://", "http://", 1)
 	}

gateway/proxy_muxer.go

@@ -12,17 +12,17 @@ import (
 	"sync/atomic"
 	"time"
 
+	"golang.org/x/net/http2/h2c"
+
 	"github.com/TykTechnologies/again"
 	"github.com/TykTechnologies/tyk/config"
 	"github.com/TykTechnologies/tyk/tcp"
 	proxyproto "github.com/pires/go-proxyproto"
 	cache "github.com/pmylund/go-cache"
 
-	"golang.org/x/net/http2"
-	"golang.org/x/net/http2/h2c"
-
 	"github.com/gorilla/mux"
 	"github.com/sirupsen/logrus"
+	"golang.org/x/net/http2"
 )
 
 // handleWrapper's only purpose is to allow router to be dynamically replaced
@@ -126,6 +126,7 @@ func (m *proxyMux) router(port int, protocol string) *mux.Router {
 }
 
 func (m *proxyMux) setRouter(port int, protocol string, router *mux.Router) {
+
 	if port == 0 {
 		port = config.Global().ListenPort
 	}
@@ -401,6 +402,7 @@ func (m *proxyMux) serve() {
 			}
 			var h http.Handler
 			h = &handleWrapper{p.router}
+
 			if p.protocol == "h2c" {
 				// wrapping handler in h2c. This ensures all features including tracing work
 				// in h2c services.
@@ -410,6 +412,7 @@ func (m *proxyMux) serve() {
 					h: h2c.NewHandler(p.router, h2s),
 				}
 			}
+
 			addr := config.Global().ListenAddress + ":" + strconv.Itoa(p.port)
 			p.httpServer = &http.Server{
 				Addr:         addr,
@@ -421,11 +424,8 @@ func (m *proxyMux) serve() {
 			if config.Global().CloseConnections {
 				p.httpServer.SetKeepAlivesEnabled(false)
 			}
-
 			go p.httpServer.Serve(p.listener)
-
 		}
-
 		p.started = true
 	}
 }