Move port forward protocol constant to subpackage

Move port forward protocol name constant to a subpackage underneath
pkg/kubelet to avoid flags applicable to the kubelet leaking into
kubectl. Eventually, handlers for specific protocol versions will move
into the new subpackage as well.

pkg/client/unversioned/portforward/portforward.go

@@ -29,7 +29,7 @@ import (
 
 	"github.com/golang/glog"
 	"k8s.io/kubernetes/pkg/api"
-	"k8s.io/kubernetes/pkg/kubelet"
+	"k8s.io/kubernetes/pkg/kubelet/portforward"
 	"k8s.io/kubernetes/pkg/util"
 	"k8s.io/kubernetes/pkg/util/httpstream"
 )
@@ -129,7 +129,7 @@ func (pf *PortForwarder) ForwardPorts() error {
 	defer pf.Close()
 
 	var err error
-	pf.streamConn, _, err = pf.dialer.Dial(kubelet.PortForwardProtocolV1Name)
+	pf.streamConn, _, err = pf.dialer.Dial(portforward.PortForwardProtocolV1Name)
 	if err != nil {
 		return fmt.Errorf("error upgrading connection: %s", err)
 	}

pkg/kubelet/portforward/constants.go

@@ -0,0 +1,21 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// package portforward contains server-side logic for handling port forwarding requests.
+package portforward
+
+// The subprotocol "portforward.k8s.io" is used for port forwarding.
+const PortForwardProtocolV1Name = "portforward.k8s.io"

pkg/kubelet/server.go

@@ -48,6 +48,7 @@ import (
 	"k8s.io/kubernetes/pkg/healthz"
 	"k8s.io/kubernetes/pkg/httplog"
 	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
+	"k8s.io/kubernetes/pkg/kubelet/portforward"
 	"k8s.io/kubernetes/pkg/types"
 	"k8s.io/kubernetes/pkg/util"
 	"k8s.io/kubernetes/pkg/util/flushwriter"
@@ -781,17 +782,14 @@ func (s *Server) getPortForward(request *restful.Request, response *restful.Resp
 	ServePortForward(response.ResponseWriter, request.Request, s.host, podName, uid, s.host.StreamingConnectionIdleTimeout(), defaultStreamCreationTimeout)
 }
 
-// The subprotocol "portforward.k8s.io" is used for port forwarding.
-const PortForwardProtocolV1Name = "portforward.k8s.io"
-
 // ServePortForward handles a port forwarding request.  A single request is
 // kept alive as long as the client is still alive and the connection has not
 // been timed out due to idleness. This function handles multiple forwarded
 // connections; i.e., multiple `curl http://localhost:8888/` requests will be
 // handled by a single invocation of ServePortForward.
 func ServePortForward(w http.ResponseWriter, req *http.Request, portForwarder PortForwarder, podName string, uid types.UID, idleTimeout time.Duration, streamCreationTimeout time.Duration) {
-	supportedPortForwardProtocols := []string{PortForwardProtocolV1Name}
+	supportedPortForwardProtocols := []string{portforward.PortForwardProtocolV1Name}
-	_, err := httpstream.Handshake(req, w, supportedPortForwardProtocols, PortForwardProtocolV1Name)
+	_, err := httpstream.Handshake(req, w, supportedPortForwardProtocols, portforward.PortForwardProtocolV1Name)
 	// negotiated protocol isn't currently used server side, but could be in the future
 	if err != nil {
 		// Handshake writes the error to the client