Prepare to introduce websockets for exec and portforward

Refactor the code in remotecommand to better represent the structure of
what is common between portforward and exec.

pkg/kubectl/cmd/exec.go

@@ -25,7 +25,6 @@ import (
 	"github.com/spf13/cobra"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	remotecommandconsts "k8s.io/apimachinery/pkg/util/remotecommand"
 	restclient "k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/remotecommand"
 	"k8s.io/kubernetes/pkg/api"
@@ -101,17 +100,16 @@ type RemoteExecutor interface {
 type DefaultRemoteExecutor struct{}
 
 func (*DefaultRemoteExecutor) Execute(method string, url *url.URL, config *restclient.Config, stdin io.Reader, stdout, stderr io.Writer, tty bool, terminalSizeQueue remotecommand.TerminalSizeQueue) error {
-	exec, err := remotecommand.NewExecutor(config, method, url)
+	exec, err := remotecommand.NewSPDYExecutor(config, method, url)
 	if err != nil {
 		return err
 	}
 	return exec.Stream(remotecommand.StreamOptions{
-		SupportedProtocols: remotecommandconsts.SupportedStreamingProtocols,
-		Stdin:              stdin,
-		Stdout:             stdout,
-		Stderr:             stderr,
-		Tty:                tty,
-		TerminalSizeQueue:  terminalSizeQueue,
+		Stdin:             stdin,
+		Stdout:            stdout,
+		Stderr:            stderr,
+		Tty:               tty,
+		TerminalSizeQueue: terminalSizeQueue,
 	})
 }