Allow objects to serialize their nested objects

Introduce an optional interface for callers to encode themselves.

pkg/runtime/interfaces.go

@@ -154,6 +154,18 @@ type StorageSerializer interface {
 	DecoderToVersion(serializer Decoder, gv GroupVersioner) Decoder
 }
 
+// NestedObjectEncoder is an optional interface that objects may implement to be given
+// an opportunity to encode any nested Objects / RawExtensions during serialization.
+type NestedObjectEncoder interface {
+	EncodeNestedObjects(e Encoder) error
+}
+
+// NestedObjectDecoder is an optional interface that objects may implement to be given
+// an opportunity to decode any nested Objects / RawExtensions during serialization.
+type NestedObjectDecoder interface {
+	DecodeNestedObjects(d Decoder) error
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // Non-codec interfaces
 

pkg/runtime/serializer/codec_factory.go

@@ -17,8 +17,6 @@ limitations under the License.
 package serializer
 
 import (
-	"io"
-
 	"k8s.io/kubernetes/pkg/api/unversioned"
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/runtime/serializer/json"
@@ -336,47 +334,15 @@ type DirectCodecFactory struct {
 
 // EncoderForVersion returns an encoder that does not do conversion. gv is ignored.
 func (f DirectCodecFactory) EncoderForVersion(serializer runtime.Encoder, _ runtime.GroupVersioner) runtime.Encoder {
-	return DirectCodec{
-		runtime.NewCodec(serializer, nil),
-		f.CodecFactory.scheme,
+	return versioning.DirectEncoder{
+		Encoder:     serializer,
+		ObjectTyper: f.CodecFactory.scheme,
 	}
 }
 
 // DecoderToVersion returns an decoder that does not do conversion. gv is ignored.
 func (f DirectCodecFactory) DecoderToVersion(serializer runtime.Decoder, _ runtime.GroupVersioner) runtime.Decoder {
-	return DirectCodec{
-		runtime.NewCodec(nil, serializer),
-		nil,
+	return versioning.DirectDecoder{
+		Decoder: serializer,
 	}
 }
-
-// DirectCodec is a codec that does not do conversion. It sets the gvk during serialization, and removes the gvk during deserialization.
-type DirectCodec struct {
-	runtime.Serializer
-	runtime.ObjectTyper
-}
-
-// EncodeToStream does not do conversion. It sets the gvk during serialization. overrides are ignored.
-func (c DirectCodec) Encode(obj runtime.Object, stream io.Writer) error {
-	gvks, _, err := c.ObjectTyper.ObjectKinds(obj)
-	if err != nil {
-		return err
-	}
-	kind := obj.GetObjectKind()
-	oldGVK := kind.GroupVersionKind()
-	kind.SetGroupVersionKind(gvks[0])
-	err = c.Serializer.Encode(obj, stream)
-	kind.SetGroupVersionKind(oldGVK)
-	return err
-}
-
-// Decode does not do conversion. It removes the gvk during deserialization.
-func (c DirectCodec) Decode(data []byte, defaults *unversioned.GroupVersionKind, into runtime.Object) (runtime.Object, *unversioned.GroupVersionKind, error) {
-	obj, gvk, err := c.Serializer.Decode(data, defaults, into)
-	if obj != nil {
-		kind := obj.GetObjectKind()
-		// clearing the gvk is just a convention of a codec
-		kind.SetGroupVersionKind(unversioned.GroupVersionKind{})
-	}
-	return obj, gvk, err
-}

pkg/runtime/serializer/versioning/versioning.go

@@ -88,6 +88,12 @@ func (c *codec) Decode(data []byte, defaultGVK *unversioned.GroupVersionKind, in
 		return nil, gvk, err
 	}
 
+	if d, ok := obj.(runtime.NestedObjectDecoder); ok {
+		if err := d.DecodeNestedObjects(DirectDecoder{c.decoder}); err != nil {
+			return nil, gvk, err
+		}
+	}
+
 	// if we specify a target, use generic conversion.
 	if into != nil {
 		if into == obj {
@@ -131,21 +137,8 @@ func (c *codec) Decode(data []byte, defaultGVK *unversioned.GroupVersionKind, in
 // Encode ensures the provided object is output in the appropriate group and version, invoking
 // conversion if necessary. Unversioned objects (according to the ObjectTyper) are output as is.
 func (c *codec) Encode(obj runtime.Object, w io.Writer) error {
-	switch t := obj.(type) {
-	case *runtime.Unknown:
-		if gv, ok := runtime.PreferredGroupVersion(c.encodeVersion); ok {
-			t.APIVersion = gv.String()
-		}
-		return c.encoder.Encode(obj, w)
-	case *runtime.Unstructured:
-		if gv, ok := runtime.PreferredGroupVersion(c.encodeVersion); ok {
-			t.SetAPIVersion(gv.String())
-		}
-		return c.encoder.Encode(obj, w)
-	case *runtime.UnstructuredList:
-		if gv, ok := runtime.PreferredGroupVersion(c.encodeVersion); ok {
-			t.SetAPIVersion(gv.String())
-		}
+	switch obj.(type) {
+	case *runtime.Unknown, *runtime.Unstructured, *runtime.UnstructuredList:
 		return c.encoder.Encode(obj, w)
 	}
 
@@ -155,6 +148,11 @@ func (c *codec) Encode(obj runtime.Object, w io.Writer) error {
 	}
 
 	if c.encodeVersion == nil || isUnversioned {
+		if e, ok := obj.(runtime.NestedObjectEncoder); ok {
+			if err := e.EncodeNestedObjects(DirectEncoder{Encoder: c.encoder, ObjectTyper: c.typer}); err != nil {
+				return err
+			}
+		}
 		objectKind := obj.GetObjectKind()
 		old := objectKind.GroupVersionKind()
 		objectKind.SetGroupVersionKind(gvks[0])
@@ -170,9 +168,52 @@ func (c *codec) Encode(obj runtime.Object, w io.Writer) error {
 	if err != nil {
 		return err
 	}
+
+	if e, ok := out.(runtime.NestedObjectEncoder); ok {
+		if err := e.EncodeNestedObjects(DirectEncoder{Encoder: c.encoder, ObjectTyper: c.typer}); err != nil {
+			return err
+		}
+	}
+
 	// Conversion is responsible for setting the proper group, version, and kind onto the outgoing object
 	err = c.encoder.Encode(out, w)
 	// restore the old GVK, in case conversion returned the same object
 	objectKind.SetGroupVersionKind(old)
 	return err
 }
+
+// DirectEncoder serializes an object and ensures the GVK is set.
+type DirectEncoder struct {
+	runtime.Encoder
+	runtime.ObjectTyper
+}
+
+// Encode does not do conversion. It sets the gvk during serialization.
+func (e DirectEncoder) Encode(obj runtime.Object, stream io.Writer) error {
+	gvks, _, err := e.ObjectTyper.ObjectKinds(obj)
+	if err != nil {
+		return err
+	}
+	kind := obj.GetObjectKind()
+	oldGVK := kind.GroupVersionKind()
+	kind.SetGroupVersionKind(gvks[0])
+	err = e.Encoder.Encode(obj, stream)
+	kind.SetGroupVersionKind(oldGVK)
+	return err
+}
+
+// DirectDecoder clears the group version kind of a deserialized object.
+type DirectDecoder struct {
+	runtime.Decoder
+}
+
+// Decode does not do conversion. It removes the gvk during deserialization.
+func (d DirectDecoder) Decode(data []byte, defaults *unversioned.GroupVersionKind, into runtime.Object) (runtime.Object, *unversioned.GroupVersionKind, error) {
+	obj, gvk, err := d.Decoder.Decode(data, defaults, into)
+	if obj != nil {
+		kind := obj.GetObjectKind()
+		// clearing the gvk is just a convention of a codec
+		kind.SetGroupVersionKind(unversioned.GroupVersionKind{})
+	}
+	return obj, gvk, err
+}

pkg/runtime/serializer/versioning/versioning_test.go

@@ -19,6 +19,7 @@ package versioning
 import (
 	"fmt"
 	"io"
+	"io/ioutil"
 	"reflect"
 	"testing"
 
@@ -37,6 +38,60 @@ func (d *testDecodable) GetObjectKind() unversioned.ObjectKind                {
 func (d *testDecodable) SetGroupVersionKind(gvk unversioned.GroupVersionKind) { d.gvk = gvk }
 func (d *testDecodable) GroupVersionKind() unversioned.GroupVersionKind       { return d.gvk }
 
+type testNestedDecodable struct {
+	Other string
+	Value int `json:"value"`
+
+	gvk          unversioned.GroupVersionKind
+	nestedCalled bool
+	nestedErr    error
+}
+
+func (d *testNestedDecodable) GetObjectKind() unversioned.ObjectKind                { return d }
+func (d *testNestedDecodable) SetGroupVersionKind(gvk unversioned.GroupVersionKind) { d.gvk = gvk }
+func (d *testNestedDecodable) GroupVersionKind() unversioned.GroupVersionKind       { return d.gvk }
+
+func (d *testNestedDecodable) EncodeNestedObjects(e runtime.Encoder) error {
+	d.nestedCalled = true
+	return d.nestedErr
+}
+
+func (d *testNestedDecodable) DecodeNestedObjects(_ runtime.Decoder) error {
+	d.nestedCalled = true
+	return d.nestedErr
+}
+
+func TestNestedDecode(t *testing.T) {
+	n := &testNestedDecodable{nestedErr: fmt.Errorf("unable to decode")}
+	decoder := &mockSerializer{obj: n}
+	codec := NewCodec(nil, decoder, nil, nil, nil, nil, nil, nil)
+	if _, _, err := codec.Decode([]byte(`{}`), nil, n); err != n.nestedErr {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if !n.nestedCalled {
+		t.Errorf("did not invoke nested decoder")
+	}
+}
+
+func TestNestedEncode(t *testing.T) {
+	n := &testNestedDecodable{nestedErr: fmt.Errorf("unable to decode")}
+	n2 := &testNestedDecodable{nestedErr: fmt.Errorf("unable to decode 2")}
+	encoder := &mockSerializer{obj: n}
+	codec := NewCodec(
+		encoder, nil,
+		&checkConvertor{obj: n2, groupVersion: unversioned.GroupVersion{Group: "other"}},
+		nil, nil,
+		&mockTyper{gvks: []unversioned.GroupVersionKind{{Kind: "test"}}},
+		unversioned.GroupVersion{Group: "other"}, nil,
+	)
+	if err := codec.Encode(n, ioutil.Discard); err != n2.nestedErr {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if n.nestedCalled || !n2.nestedCalled {
+		t.Errorf("did not invoke correct nested decoder")
+	}
+}
+
 func TestDecode(t *testing.T) {
 	gvk1 := &unversioned.GroupVersionKind{Kind: "Test", Group: "other", Version: "blah"}
 	decodable1 := &testDecodable{}
@@ -300,10 +355,15 @@ func (c *mockCreater) New(kind unversioned.GroupVersionKind) (runtime.Object, er
 }
 
 type mockTyper struct {
-	gvk *unversioned.GroupVersionKind
-	err error
+	gvks        []unversioned.GroupVersionKind
+	unversioned bool
+	err         error
 }
 
-func (t *mockTyper) ObjectKind(obj runtime.Object) (*unversioned.GroupVersionKind, bool, error) {
-	return t.gvk, false, t.err
+func (t *mockTyper) ObjectKinds(obj runtime.Object) ([]unversioned.GroupVersionKind, bool, error) {
+	return t.gvks, t.unversioned, t.err
+}
+
+func (t *mockTyper) Recognizes(_ unversioned.GroupVersionKind) bool {
+	return true
 }