let DirectEncoder take a hint of what gvk to set during its construction

pkg/runtime/serializer/codec_factory.go

@@ -220,9 +220,10 @@ type DirectCodecFactory struct {
 	CodecFactory
 }
 
-// EncoderForVersion returns an encoder that does not do conversion. gv is ignored.
-func (f DirectCodecFactory) EncoderForVersion(serializer runtime.Encoder, _ runtime.GroupVersioner) runtime.Encoder {
+// EncoderForVersion returns an encoder that does not do conversion.
+func (f DirectCodecFactory) EncoderForVersion(serializer runtime.Encoder, version runtime.GroupVersioner) runtime.Encoder {
 	return versioning.DirectEncoder{
+		Version:     version,
 		Encoder:     serializer,
 		ObjectTyper: f.CodecFactory.scheme,
 	}

pkg/runtime/serializer/versioning/versioning.go

@@ -227,6 +227,7 @@ func (c *codec) Encode(obj runtime.Object, w io.Writer) error {
 
 // DirectEncoder serializes an object and ensures the GVK is set.
 type DirectEncoder struct {
+	Version runtime.GroupVersioner
 	runtime.Encoder
 	runtime.ObjectTyper
 }
@@ -242,7 +243,14 @@ func (e DirectEncoder) Encode(obj runtime.Object, stream io.Writer) error {
 	}
 	kind := obj.GetObjectKind()
 	oldGVK := kind.GroupVersionKind()
-	kind.SetGroupVersionKind(gvks[0])
+	gvk := gvks[0]
+	if e.Version != nil {
+		preferredGVK, ok := e.Version.KindForGroupVersionKinds(gvks)
+		if ok {
+			gvk = preferredGVK
+		}
+	}
+	kind.SetGroupVersionKind(gvk)
 	err = e.Encoder.Encode(obj, stream)
 	kind.SetGroupVersionKind(oldGVK)
 	return err

pkg/runtime/serializer/versioning/versioning_test.go

@@ -329,8 +329,9 @@ func (c *checkConvertor) ConvertFieldLabel(version, kind, label, value string) (
 }
 
 type mockSerializer struct {
-	err error
-	obj runtime.Object
+	err            error
+	obj            runtime.Object
+	encodingObjGVK schema.GroupVersionKind
 
 	defaults, actual *schema.GroupVersionKind
 	into             runtime.Object
@@ -344,6 +345,7 @@ func (s *mockSerializer) Decode(data []byte, defaults *schema.GroupVersionKind,
 
 func (s *mockSerializer) Encode(obj runtime.Object, w io.Writer) error {
 	s.obj = obj
+	s.encodingObjGVK = obj.GetObjectKind().GroupVersionKind()
 	return s.err
 }
 
@@ -369,3 +371,29 @@ func (t *mockTyper) ObjectKinds(obj runtime.Object) ([]schema.GroupVersionKind,
 func (t *mockTyper) Recognizes(_ schema.GroupVersionKind) bool {
 	return true
 }
+
+func TestDirectCodecEncode(t *testing.T) {
+	serializer := mockSerializer{}
+	typer := mockTyper{
+		gvks: []schema.GroupVersionKind{
+			{
+				Group: "wrong_group",
+				Kind:  "some_kind",
+			},
+			{
+				Group: "expected_group",
+				Kind:  "some_kind",
+			},
+		},
+	}
+
+	c := DirectEncoder{
+		Version:     schema.GroupVersion{Group: "expected_group"},
+		Encoder:     &serializer,
+		ObjectTyper: &typer,
+	}
+	c.Encode(&testDecodable{}, ioutil.Discard)
+	if e, a := "expected_group", serializer.encodingObjGVK.Group; e != a {
+		t.Errorf("expected group to be %v, got %v", e, a)
+	}
+}