Add --address to kubectl proxy

pkg/kubectl/cmd/proxy.go

@@ -77,6 +77,7 @@ The above lets you 'curl localhost:8001/custom/api/v1/pods'
 	cmd.Flags().String("accept-hosts", kubectl.DefaultHostAcceptRE, "Regular expression for hosts that the proxy should accept.")
 	cmd.Flags().String("reject-methods", kubectl.DefaultMethodRejectRE, "Regular expression for HTTP methods that the proxy should reject.")
 	cmd.Flags().IntP("port", "p", default_port, "The port on which to run the proxy. Set to 0 to pick a random port.")
+	cmd.Flags().StringP("address", "", "127.0.0.1", "The IP address on which to serve on.")
 	cmd.Flags().Bool("disable-filter", false, "If true, disable request filtering in the proxy. This is dangerous, and can leave you vulnerable to XSRF attacks, when used with an accessible port.")
 	cmd.Flags().StringP("unix-socket", "u", "", "Unix socket on which to run the proxy.")
 	return cmd
@@ -85,6 +86,7 @@ The above lets you 'curl localhost:8001/custom/api/v1/pods'
 func RunProxy(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command) error {
 	path := cmdutil.GetFlagString(cmd, "unix-socket")
 	port := cmdutil.GetFlagInt(cmd, "port")
+	address := cmdutil.GetFlagString(cmd, "address")
 
 	if port != default_port && path != "" {
 		return errors.New("Don't specify both --unix-socket and --port")
@@ -122,7 +124,7 @@ func RunProxy(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command) error {
 	// when it is chosen by os (eg: port == 0)
 	var l net.Listener
 	if path == "" {
-		l, err = server.Listen(port)
+		l, err = server.Listen(address, port)
 	} else {
 		l, err = server.ListenUnix(path)
 	}

pkg/kubectl/proxy_server.go

@@ -179,8 +179,8 @@ func NewProxyServer(filebase string, apiProxyPrefix string, staticPrefix string,
 }
 
 // Listen is a simple wrapper around net.Listen.
-func (s *ProxyServer) Listen(port int) (net.Listener, error) {
-	return net.Listen("tcp", fmt.Sprintf("127.0.0.1:%d", port))
+func (s *ProxyServer) Listen(address string, port int) (net.Listener, error) {
+	return net.Listen("tcp", fmt.Sprintf("%s:%d", address, port))
 }
 
 // ListenUnix does net.Listen for a unix socket