Fix kubectl sort-by metadata issue.

Internal types are not supposed to have json metadata (though in kubernetes
they do) as it is true with openshift types. That means sort-by must work
on versioned objects for sorting, otherwise it produces "error: metadata
is not found" error if it sorts internal types without json metadata.

This PR converts internal types objects to versioned objects and sort-by
sorts them correctly without medata error, and then it prints
corresponding internal objects in sorted order.

pkg/kubectl/cmd/get.go

@@ -248,6 +248,23 @@ func RunGet(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string
 	sorting, err := cmd.Flags().GetString("sort-by")
 	var sorter *kubectl.RuntimeSort
 	if err == nil && len(sorting) > 0 && len(objs) > 1 {
+		clientConfig, err := f.ClientConfig()
+		if err != nil {
+			return err
+		}
+
+		version, err := cmdutil.OutputVersion(cmd, clientConfig.GroupVersion)
+		if err != nil {
+			return err
+		}
+
+		for ix := range infos {
+			objs[ix], err = infos[ix].Mapping.ConvertToVersion(infos[ix].Object, version.String())
+			if err != nil {
+				return err
+			}
+		}
+
 		// TODO: questionable
 		if sorter, err = kubectl.SortObjects(f.Decoder(true), objs, sorting); err != nil {
 			return err
@@ -262,10 +279,13 @@ func RunGet(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string
 
 	for ix := range objs {
 		var mapping *meta.RESTMapping
+		var original runtime.Object
 		if sorter != nil {
 			mapping = infos[sorter.OriginalPosition(ix)].Mapping
+			original = infos[sorter.OriginalPosition(ix)].Object
 		} else {
 			mapping = infos[ix].Mapping
+			original = infos[ix].Object
 		}
 		if printer == nil || lastMapping == nil || mapping == nil || mapping.Resource != lastMapping.Resource {
 			printer, err = f.PrinterForMapping(cmd, mapping, allNamespaces)
@@ -275,12 +295,12 @@ func RunGet(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string
 			lastMapping = mapping
 		}
 		if _, found := printer.(*kubectl.HumanReadablePrinter); found {
-			if err := printer.PrintObj(objs[ix], w); err != nil {
+			if err := printer.PrintObj(original, w); err != nil {
 				return err
 			}
 			continue
 		}
-		if err := printer.PrintObj(objs[ix], w); err != nil {
+		if err := printer.PrintObj(original, w); err != nil {
 			return err
 		}
 	}

pkg/kubectl/cmd/get_test.go

@@ -273,6 +273,56 @@ func TestGetObjects(t *testing.T) {
 	}
 }
 
+func TestGetSortedObjects(t *testing.T) {
+	pods := &api.PodList{
+		ListMeta: unversioned.ListMeta{
+			ResourceVersion: "15",
+		},
+		Items: []api.Pod{
+			{
+				ObjectMeta: api.ObjectMeta{Name: "c", Namespace: "test", ResourceVersion: "10"},
+				Spec:       apitesting.DeepEqualSafePodSpec(),
+			},
+			{
+				ObjectMeta: api.ObjectMeta{Name: "b", Namespace: "test", ResourceVersion: "11"},
+				Spec:       apitesting.DeepEqualSafePodSpec(),
+			},
+			{
+				ObjectMeta: api.ObjectMeta{Name: "a", Namespace: "test", ResourceVersion: "9"},
+				Spec:       apitesting.DeepEqualSafePodSpec(),
+			},
+		},
+	}
+
+	f, tf, codec := NewAPIFactory()
+	tf.Printer = &testPrinter{}
+	tf.Client = &fake.RESTClient{
+		Codec: codec,
+		Resp:  &http.Response{StatusCode: 200, Body: objBody(codec, pods)},
+	}
+	tf.Namespace = "test"
+	tf.ClientConfig = &restclient.Config{ContentConfig: restclient.ContentConfig{GroupVersion: &unversioned.GroupVersion{Version: "v1"}}}
+
+	buf := bytes.NewBuffer([]byte{})
+	cmd := NewCmdGet(f, buf)
+	cmd.SetOutput(buf)
+
+	// sorting with metedata.name
+	cmd.Flags().Set("sort-by", ".metadata.name")
+	cmd.Run(cmd, []string{"pods"})
+
+	// expect sorted: a,b,c
+	expected := []runtime.Object{&pods.Items[2], &pods.Items[1], &pods.Items[0]}
+	actual := tf.Printer.(*testPrinter).Objects
+	if !reflect.DeepEqual(expected, actual) {
+		t.Errorf("unexpected object: %#v", actual)
+	}
+	if len(buf.String()) == 0 {
+		t.Errorf("unexpected empty output")
+	}
+
+}
+
 func TestGetObjectsIdentifiedByFile(t *testing.T) {
 	pods, _, _ := testData()