allow conversions.Scheme to expose intermidiate versioned api object

pkg/conversion/decode.go

@@ -22,31 +22,38 @@ import (
 	"fmt"
 )
 
-// Decode converts a JSON string back into a pointer to an api object.
-// Deduces the type based upon the fields added by the MetaInsertionFactory
-// technique. The object will be converted, if necessary, into the
-// s.InternalVersion type before being returned. Decode will not decode
-// objects without version set unless InternalVersion is also "".
-func (s *Scheme) Decode(data []byte) (interface{}, error) {
-	version, kind, err := s.DataVersionAndKind(data)
+func (s *Scheme) DecodeToVersionedObject(data []byte) (obj interface{}, version, kind string, err error) {
+	version, kind, err = s.DataVersionAndKind(data)
 	if err != nil {
-		return nil, err
+		return
 	}
 	if version == "" && s.InternalVersion != "" {
-		return nil, fmt.Errorf("version not set in '%s'", string(data))
+		return nil, "", "", fmt.Errorf("version not set in '%s'", string(data))
 	}
 	if kind == "" {
-		return nil, fmt.Errorf("kind not set in '%s'", string(data))
+		return nil, "", "", fmt.Errorf("kind not set in '%s'", string(data))
 	}
-	obj, err := s.NewObject(version, kind)
+	obj, err = s.NewObject(version, kind)
 	if err != nil {
-		return nil, err
+		return nil, "", "", err
 	}
 
 	if err := json.Unmarshal(data, obj); err != nil {
-		return nil, err
+		return nil, "", "", err
 	}
+	return
+}
 
+// Decode converts a JSON string back into a pointer to an api object.
+// Deduces the type based upon the fields added by the MetaInsertionFactory
+// technique. The object will be converted, if necessary, into the
+// s.InternalVersion type before being returned. Decode will not decode
+// objects without version set unless InternalVersion is also "".
+func (s *Scheme) Decode(data []byte) (interface{}, error) {
+	obj, version, kind, err := s.DecodeToVersionedObject(data)
+	if err != nil {
+		return nil, err
+	}
 	// Version and Kind should be blank in memory.
 	if err := s.SetVersionAndKind("", "", obj); err != nil {
 		return nil, err