Add --watch to get command

pkg/kubectl/watchloop.go

@@ -0,0 +1,47 @@
+/*
+Copyright 2014 Google Inc. 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 kubectl
+
+import (
+	"io"
+	"os"
+	"os/signal"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/watch"
+)
+
+// WatchLoop loops, writing objects in the events from w to printer.
+// If user sends interrupt signal, shut down cleanly. Otherwise, never return.
+func WatchLoop(w watch.Interface, printer ResourcePrinter, out io.Writer) {
+	signals := make(chan os.Signal, 1)
+	signal.Notify(signals, os.Interrupt)
+	defer signal.Stop(signals)
+	for {
+		select {
+		case event, ok := <-w.ResultChan():
+			if !ok {
+				return
+			}
+			// TODO: need to print out added/modified/deleted!
+			if err := printer.PrintObj(event.Object, out); err != nil {
+				w.Stop()
+			}
+		case <-signals:
+			w.Stop()
+		}
+	}
+}