fix: websocket when the connection upgrade failed.

glide.lock

@@ -1,5 +1,5 @@
-hash: e59e8244152a823cd3633fb09cdd583c4e5be78d7b50fb7047ba6b6a9ed5e8ec
-updated: 2017-05-19T23:30:19.890844996+02:00
+hash: 6e206389bc4f381387be8b5f0cc5a41224329752654ddb3c2a805adde0333217
+updated: 2017-06-17T14:30:19.890844996+02:00
 imports:
 - name: cloud.google.com/go
   version: 2e6a95edb1071d750f6d7db777bf66cd2997af6c
@@ -409,7 +409,7 @@ imports:
 - name: github.com/vdemeester/docker-events
   version: be74d4929ec1ad118df54349fda4b0cba60f849b
 - name: github.com/vulcand/oxy
-  version: f88530866c561d24a6b5aac49f76d6351b788b9f
+  version: ad5bdb606fa9c64db267f0e43d63834908bdb05e
   repo: https://github.com/containous/oxy.git
   vcs: git
   subpackages:

glide.yaml

@@ -8,7 +8,7 @@ import:
 - package: github.com/cenk/backoff
 - package: github.com/containous/flaeg
 - package: github.com/vulcand/oxy
-  version: f88530866c561d24a6b5aac49f76d6351b788b9f
+  version: ad5bdb606fa9c64db267f0e43d63834908bdb05e
   repo: https://github.com/containous/oxy.git
   vcs: git
   subpackages:

vendor/github.com/vulcand/oxy/forward/fwd.go

@@ -4,6 +4,7 @@
 package forward
 
 import (
+	"bufio"
 	"crypto/tls"
 	"io"
 	"net"
@@ -290,14 +291,26 @@ func (f *websocketForwarder) serveHTTP(w http.ResponseWriter, req *http.Request,
 		ctx.errHandler.ServeHTTP(w, req, err)
 		return
 	}
-	errc := make(chan error, 2)
-	replicate := func(dst io.Writer, src io.Reader) {
-		_, err := io.Copy(dst, src)
-		errc <- err
+
+	br := bufio.NewReader(targetConn)
+	resp, err := http.ReadResponse(br, req)
+	resp.Write(underlyingConn)
+	defer resp.Body.Close()
+
+	// We connect the conn only if the switching protocol has not failed
+	if resp.StatusCode == http.StatusSwitchingProtocols {
+		ctx.log.Infof("Switching protocol success")
+		errc := make(chan error, 2)
+		replicate := func(dst io.Writer, src io.Reader) {
+			_, err := io.Copy(dst, src)
+			errc <- err
+		}
+		go replicate(targetConn, underlyingConn)
+		go replicate(underlyingConn, targetConn)
+		<-errc
+	} else {
+		ctx.log.Infof("Switching protocol failed")
 	}
-	go replicate(targetConn, underlyingConn)
-	go replicate(underlyingConn, targetConn)
-	<-errc
 }
 
 // copyRequest makes a copy of the specified request.