add portforwarding support to node/api (#1102)

Co-authored-by: Pablo Borrelli <pablo.borrelli0@gmail.com>
Co-authored-by: windyear <1280027646@qq.com>

internal/kubernetes/portforward/constants.go

@@ -0,0 +1,24 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+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
+
+// ProtocolV1Name is the name of the subprotocol used for port forwarding.
+const ProtocolV1Name = "portforward.k8s.io"
+
+// SupportedProtocols are the supported port forwarding protocols.
+var SupportedProtocols = []string{ProtocolV1Name}