Extract execInContainer

Signed-off-by: Lantao Liu <lantaol@google.com>

pkg/server/streaming.go

@@ -0,0 +1,47 @@
+/*
+Copyright 2017 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 server
+
+import (
+	"k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/client-go/tools/remotecommand"
+	_ "k8s.io/kubernetes/pkg/kubelet/server/streaming"
+)
+
+// handleResizing spawns a goroutine that processes the resize channel, calling resizeFunc for each
+// remotecommand.TerminalSize received from the channel. The resize channel must be closed elsewhere to stop the
+// goroutine.
+func handleResizing(resize <-chan remotecommand.TerminalSize, resizeFunc func(size remotecommand.TerminalSize)) {
+	if resize == nil {
+		return
+	}
+
+	go func() {
+		defer runtime.HandleCrash()
+
+		for {
+			size, ok := <-resize
+			if !ok {
+				return
+			}
+			if size.Height < 1 || size.Width < 1 {
+				continue
+			}
+			resizeFunc(size)
+		}
+	}()
+}