Kubectl namespace support

Add unit test for load namespace info
Different message on display of namespace versus setting namespace

pkg/kubectl/cmd/namespace.go

@@ -0,0 +1,60 @@
+/*
+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 cmd
+
+import (
+	"io"
+
+	"fmt"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubectl"
+	"github.com/spf13/cobra"
+)
+
+func NewCmdNamespace(out io.Writer) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "namespace [<namespace>]",
+		Short: "Set and view the current Kubernetes namespace",
+		Long: `Set and view the current Kubernetes namespace scope for command line requests.
+
+A Kubernetes namespace subdivides the cluster into groups of logically related pods, services, and replication controllers.
+
+Examples:
+  $ kubectl namespace 
+  Using namespace default
+
+  $ kubectl namespace other
+  Set current namespace to other`,
+		Run: func(cmd *cobra.Command, args []string) {
+			nsPath := getFlagString(cmd, "ns-path")
+			var err error
+			var ns *kubectl.NamespaceInfo
+			switch len(args) {
+			case 0:
+				ns, err = kubectl.LoadNamespaceInfo(nsPath)
+				fmt.Printf("Using namespace %s\n", ns.Namespace)
+			case 1:
+				ns = &kubectl.NamespaceInfo{Namespace: args[0]}
+				err = kubectl.SaveNamespaceInfo(nsPath, ns)
+				fmt.Printf("Set current namespace to %s\n", ns.Namespace)
+			default:
+				usageError(cmd, "kubectl namespace [<namespace>]")
+			}
+			checkErr(err)
+		},
+	}
+	return cmd
+}