Genericize MetaInsertionFactory into a simpler interface

The common path code for MIF goes through a conversion cycle - it
can also be done through reflection. This simplifies the Create/Update
methods into Interpret (return version) and Update (through reflection).

In addition it uses only one MetaFactory implementation across all of
our packages which reduces a bit of duplication.

pkg/conversion/meta.go

@@ -0,0 +1,119 @@
+/*
+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 conversion
+
+import (
+	"fmt"
+	"reflect"
+
+	"gopkg.in/v1/yaml"
+)
+
+// MetaFactory is used to store and retrieve the version and kind
+// information for all objects in a scheme.
+type MetaFactory interface {
+	// Update sets the given version and kind onto the object.
+	Update(version, kind string, obj interface{}) error
+	// Interpret should return the version and kind of the wire-format of
+	// the object.
+	Interpret(data []byte) (version, kind string, err error)
+}
+
+// DefaultMetaFactory is a default factory for versioning objects in JSON/YAML. The object
+// in memory and in the default JSON serialization will use the "kind" and "apiVersion"
+// fields.
+var DefaultMetaFactory = SimpleMetaFactory{KindField: "Kind", VersionField: "APIVersion"}
+
+// SimpleMetaFactory provides default methods for retrieving the type and version of objects
+// that are identified with an "apiVersion" and "kind" fields in their JSON/YAML
+// serialization. It may be parameterized with the names of the fields in memory, or an
+// optional list of base structs to search for those fields in memory.
+type SimpleMetaFactory struct {
+	// The name of the API version field in memory of the struct
+	VersionField string
+	// The name of the kind field in memory of the struct.
+	KindField string
+	// Optional, if set will look in the named inline structs to find the fields to set.
+	BaseFields []string
+}
+
+// Interpret will return the APIVersion and Kind of the JSON/YAML wire-format
+// encoding of an object, or an error.
+func (SimpleMetaFactory) Interpret(data []byte) (version, kind string, err error) {
+	findKind := struct {
+		APIVersion string `json:"apiVersion,omitempty" yaml:"apiVersion,omitempty"`
+		Kind       string `json:"kind,omitempty" yaml:"kind,omitempty"`
+	}{}
+	// yaml is a superset of json, so we use it to decode here. That way,
+	// we understand both.
+	err = yaml.Unmarshal(data, &findKind)
+	if err != nil {
+		return "", "", fmt.Errorf("couldn't get version/kind: %v", err)
+	}
+	return findKind.APIVersion, findKind.Kind, nil
+}
+
+func (f SimpleMetaFactory) Update(version, kind string, obj interface{}) error {
+	return UpdateVersionAndKind(f.BaseFields, f.VersionField, version, f.KindField, kind, obj)
+}
+
+// UpdateVersionAndKind uses reflection to find and set the versionField and kindField fields
+// on a pointer to a struct to version and kind. Provided as a convenience for others
+// implementing MetaFactory. Pass an array to baseFields to check one or more nested structs
+// for the named fields. The version field is treated as optional if it is not present in the struct.
+func UpdateVersionAndKind(baseFields []string, versionField, version, kindField, kind string, obj interface{}) error {
+	v, err := EnforcePtr(obj)
+	if err != nil {
+		return err
+	}
+	t := v.Type()
+	name := t.Name()
+	if v.Kind() != reflect.Struct {
+		return fmt.Errorf("expected struct, but got %v: %v (%#v)", v.Kind(), name, v.Interface())
+	}
+
+	for i := range baseFields {
+		base := v.FieldByName(baseFields[i])
+		if !base.IsValid() {
+			continue
+		}
+		v = base
+	}
+
+	field := v.FieldByName(kindField)
+	if !field.IsValid() {
+		return fmt.Errorf("couldn't find %v field in %#v", kindField, v.Interface())
+	}
+	field.SetString(kind)
+
+	if field := v.FieldByName(versionField); field.IsValid() {
+		field.SetString(version)
+	}
+
+	return nil
+}
+
+// EnforcePtr ensures that obj is a pointer of some sort. Returns a reflect.Value
+// of the dereferenced pointer, ensuring that it is settable/addressable.
+// Returns an error if this is not possible.
+func EnforcePtr(obj interface{}) (reflect.Value, error) {
+	v := reflect.ValueOf(obj)
+	if v.Kind() != reflect.Ptr {
+		return reflect.Value{}, fmt.Errorf("expected pointer, but got %v", v.Type().Name())
+	}
+	return v.Elem(), nil
+}

pkg/conversion/meta_test.go

@@ -0,0 +1,244 @@
+/*
+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 conversion
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestSimpleMetaFactoryInterpret(t *testing.T) {
+	factory := SimpleMetaFactory{}
+	version, kind, err := factory.Interpret([]byte(`{"apiVersion":"1","kind":"object"}`))
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if version != "1" || kind != "object" {
+		t.Errorf("unexpected interpret: %s %s", version, kind)
+	}
+
+	// no kind or version
+	version, kind, err = factory.Interpret([]byte(`{}`))
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if version != "" || kind != "" {
+		t.Errorf("unexpected interpret: %s %s", version, kind)
+	}
+
+	// unparsable
+	version, kind, err = factory.Interpret([]byte(`{`))
+	if err == nil {
+		t.Errorf("unexpected non-error")
+	}
+}
+
+func TestSimpleMetaFactoryUpdate(t *testing.T) {
+	factory := SimpleMetaFactory{VersionField: "V", KindField: "K"}
+
+	obj := struct {
+		V string
+		K string
+	}{"1", "2"}
+
+	// must pass a pointer
+	if err := factory.Update("test", "other", obj); err == nil {
+		t.Errorf("unexpected non-error")
+	}
+	if obj.V != "1" || obj.K != "2" {
+		t.Errorf("unexpected update: %v", obj)
+	}
+
+	// updates
+	if err := factory.Update("test", "other", &obj); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if obj.V != "test" || obj.K != "other" {
+		t.Errorf("unexpected update: %v", obj)
+	}
+}
+
+func TestSimpleMetaFactoryUpdateStruct(t *testing.T) {
+	factory := SimpleMetaFactory{BaseFields: []string{"Test"}, VersionField: "V", KindField: "K"}
+
+	type Inner struct {
+		V string
+		K string
+	}
+	obj := struct {
+		Test Inner
+	}{Test: Inner{"1", "2"}}
+
+	// updates
+	if err := factory.Update("test", "other", &obj); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if obj.Test.V != "test" || obj.Test.K != "other" {
+		t.Errorf("unexpected update: %v", obj)
+	}
+}
+
+func TestMetaValues(t *testing.T) {
+	type InternalSimple struct {
+		APIVersion string `json:"apiVersion,omitempty" yaml:"apiVersion,omitempty"`
+		Kind       string `json:"kind,omitempty" yaml:"kind,omitempty"`
+		TestString string `json:"testString" yaml:"testString"`
+	}
+	type ExternalSimple struct {
+		APIVersion string `json:"apiVersion,omitempty" yaml:"apiVersion,omitempty"`
+		Kind       string `json:"kind,omitempty" yaml:"kind,omitempty"`
+		TestString string `json:"testString" yaml:"testString"`
+	}
+	s := NewScheme()
+	s.AddKnownTypeWithName("", "Simple", &InternalSimple{})
+	s.AddKnownTypeWithName("externalVersion", "Simple", &ExternalSimple{})
+
+	internalToExternalCalls := 0
+	externalToInternalCalls := 0
+
+	// Register functions to verify that scope.Meta() gets set correctly.
+	err := s.AddConversionFuncs(
+		func(in *InternalSimple, out *ExternalSimple, scope Scope) error {
+			t.Logf("internal -> external")
+			if e, a := "", scope.Meta().SrcVersion; e != a {
+				t.Fatalf("Expected '%v', got '%v'", e, a)
+			}
+			if e, a := "externalVersion", scope.Meta().DestVersion; e != a {
+				t.Fatalf("Expected '%v', got '%v'", e, a)
+			}
+			scope.Convert(&in.TestString, &out.TestString, 0)
+			internalToExternalCalls++
+			return nil
+		},
+		func(in *ExternalSimple, out *InternalSimple, scope Scope) error {
+			t.Logf("external -> internal")
+			if e, a := "externalVersion", scope.Meta().SrcVersion; e != a {
+				t.Errorf("Expected '%v', got '%v'", e, a)
+			}
+			if e, a := "", scope.Meta().DestVersion; e != a {
+				t.Fatalf("Expected '%v', got '%v'", e, a)
+			}
+			scope.Convert(&in.TestString, &out.TestString, 0)
+			externalToInternalCalls++
+			return nil
+		},
+	)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	simple := &InternalSimple{
+		TestString: "foo",
+	}
+
+	s.Log(t)
+
+	// Test Encode, Decode, and DecodeInto
+	data, err := s.EncodeToVersion(simple, "externalVersion")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	t.Logf(string(data))
+	obj2, err := s.Decode(data)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if _, ok := obj2.(*InternalSimple); !ok {
+		t.Fatalf("Got wrong type")
+	}
+	if e, a := simple, obj2; !reflect.DeepEqual(e, a) {
+		t.Errorf("Expected:\n %#v,\n Got:\n %#v", e, a)
+	}
+
+	obj3 := &InternalSimple{}
+	if err := s.DecodeInto(data, obj3); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if e, a := simple, obj3; !reflect.DeepEqual(e, a) {
+		t.Errorf("Expected:\n %#v,\n Got:\n %#v", e, a)
+	}
+
+	// Test Convert
+	external := &ExternalSimple{}
+	err = s.Convert(simple, external)
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+	if e, a := simple.TestString, external.TestString; e != a {
+		t.Errorf("Expected %v, got %v", e, a)
+	}
+
+	// Encode and Convert should each have caused an increment.
+	if e, a := 2, internalToExternalCalls; e != a {
+		t.Errorf("Expected %v, got %v", e, a)
+	}
+	// Decode and DecodeInto should each have caused an increment.
+	if e, a := 2, externalToInternalCalls; e != a {
+		t.Errorf("Expected %v, got %v", e, a)
+	}
+}
+
+func TestMetaValuesUnregisteredConvert(t *testing.T) {
+	type InternalSimple struct {
+		Version    string `json:"apiVersion,omitempty" yaml:"apiVersion,omitempty"`
+		Kind       string `json:"kind,omitempty" yaml:"kind,omitempty"`
+		TestString string `json:"testString" yaml:"testString"`
+	}
+	type ExternalSimple struct {
+		Version    string `json:"apiVersion,omitempty" yaml:"apiVersion,omitempty"`
+		Kind       string `json:"kind,omitempty" yaml:"kind,omitempty"`
+		TestString string `json:"testString" yaml:"testString"`
+	}
+	s := NewScheme()
+	s.InternalVersion = ""
+	// We deliberately don't register the types.
+
+	internalToExternalCalls := 0
+
+	// Register functions to verify that scope.Meta() gets set correctly.
+	err := s.AddConversionFuncs(
+		func(in *InternalSimple, out *ExternalSimple, scope Scope) error {
+			if e, a := "unknown", scope.Meta().SrcVersion; e != a {
+				t.Fatalf("Expected '%v', got '%v'", e, a)
+			}
+			if e, a := "unknown", scope.Meta().DestVersion; e != a {
+				t.Fatalf("Expected '%v', got '%v'", e, a)
+			}
+			scope.Convert(&in.TestString, &out.TestString, 0)
+			internalToExternalCalls++
+			return nil
+		},
+	)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	simple := &InternalSimple{TestString: "foo"}
+	external := &ExternalSimple{}
+	err = s.Convert(simple, external)
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+	if e, a := simple.TestString, external.TestString; e != a {
+		t.Errorf("Expected %v, got %v", e, a)
+	}
+
+	// Verify that our conversion handler got called.
+	if e, a := 1, internalToExternalCalls; e != a {
+		t.Errorf("Expected %v, got %v", e, a)
+	}
+}

pkg/conversion/scheme.go

@@ -19,27 +19,8 @@ package conversion
 import (
 	"fmt"
 	"reflect"
-
-	"gopkg.in/v1/yaml"
 )
 
-// MetaInsertionFactory is used to create an object to store and retrieve
-// the version and kind information for all objects. The default uses the
-// keys "version" and "kind" respectively. The object produced by this
-// factory is used to clear the version and kind fields in memory, so it
-// must match the layout of your actual api structs. (E.g., if you have your
-// version and kind field inside an inlined struct, this must produce an
-// inlined struct with the same field name.)
-type MetaInsertionFactory interface {
-	// Create should make a new object with two fields.
-	// This object will be used to encode this metadata along with your
-	// API objects, so the tags on the fields you use shouldn't conflict.
-	Create(version, kind string) interface{}
-	// Interpret should take the same type of object that Create creates.
-	// It should return the version and kind information from this object.
-	Interpret(interface{}) (version, kind string)
-}
-
 // Scheme defines an entire encoding and decoding scheme.
 type Scheme struct {
 	// versionMap allows one to figure out the go type of an object with
@@ -68,19 +49,19 @@ type Scheme struct {
 
 	// MetaInsertionFactory is used to create an object to store and retrieve
 	// the version and kind information for all objects. The default uses the
-	// keys "version" and "kind" respectively.
-	MetaInsertionFactory MetaInsertionFactory
+	// keys "apiVersion" and "kind" respectively.
+	MetaFactory MetaFactory
 }
 
 // NewScheme manufactures a new scheme.
 func NewScheme() *Scheme {
 	s := &Scheme{
-		versionMap:           map[string]map[string]reflect.Type{},
-		typeToVersion:        map[reflect.Type]string{},
-		typeToKind:           map[reflect.Type][]string{},
-		converter:            NewConverter(),
-		InternalVersion:      "",
-		MetaInsertionFactory: metaInsertion{},
+		versionMap:      map[string]map[string]reflect.Type{},
+		typeToVersion:   map[reflect.Type]string{},
+		typeToKind:      map[reflect.Type][]string{},
+		converter:       NewConverter(),
+		InternalVersion: "",
+		MetaFactory:     DefaultMetaFactory,
 	}
 	s.converter.NameFunc = s.nameFunc
 	return s
@@ -238,41 +219,10 @@ func (s *Scheme) generateConvertMeta(srcVersion, destVersion string) *Meta {
 	}
 }
 
-// metaInsertion provides a default implementation of MetaInsertionFactory.
-type metaInsertion struct {
-	Version string `json:"version,omitempty" yaml:"version,omitempty"`
-	Kind    string `json:"kind,omitempty" yaml:"kind,omitempty"`
-}
-
-// Create should make a new object with two fields.
-// This object will be used to encode this metadata along with your
-// API objects, so the tags on the fields you use shouldn't conflict.
-func (metaInsertion) Create(version, kind string) interface{} {
-	m := metaInsertion{}
-	m.Version = version
-	m.Kind = kind
-	return &m
-}
-
-// Interpret should take the same type of object that Create creates.
-// It should return the version and kind information from this object.
-func (metaInsertion) Interpret(in interface{}) (version, kind string) {
-	m := in.(*metaInsertion)
-	return m.Version, m.Kind
-}
-
 // DataVersionAndKind will return the APIVersion and Kind of the given wire-format
 // enconding of an API Object, or an error.
 func (s *Scheme) DataVersionAndKind(data []byte) (version, kind string, err error) {
-	findKind := s.MetaInsertionFactory.Create("", "")
-	// yaml is a superset of json, so we use it to decode here. That way,
-	// we understand both.
-	err = yaml.Unmarshal(data, findKind)
-	if err != nil {
-		return "", "", fmt.Errorf("couldn't get version/kind: %v", err)
-	}
-	version, kind = s.MetaInsertionFactory.Interpret(findKind)
-	return version, kind, nil
+	return s.MetaFactory.Interpret(data)
 }
 
 // ObjectVersionAndKind returns the API version and kind of the go object,
@@ -297,8 +247,7 @@ func (s *Scheme) ObjectVersionAndKind(obj interface{}) (apiVersion, kind string,
 // MetaInsertionFactory). Returns an error if this isn't possible. obj
 // must be a pointer.
 func (s *Scheme) SetVersionAndKind(version, kind string, obj interface{}) error {
-	versionAndKind := s.MetaInsertionFactory.Create(version, kind)
-	return s.converter.Convert(versionAndKind, obj, SourceToDest|IgnoreMissingFields|AllowDifferentFieldTypeNames, nil)
+	return s.MetaFactory.Update(version, kind, obj)
 }
 
 // maybeCopy copies obj if it is not a pointer, to get a settable/addressable

pkg/conversion/scheme_test.go

@@ -25,7 +25,9 @@ import (
 	"testing"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+
 	"github.com/google/gofuzz"
+	"gopkg.in/v1/yaml"
 )
 
 var fuzzIters = flag.Int("fuzz_iters", 50, "How many fuzzing iterations to do.")
@@ -129,30 +131,28 @@ func GetTestScheme() *Scheme {
 	s.AddKnownTypeWithName("", "TestType3", &TestType1{})
 	s.AddKnownTypeWithName("v1", "TestType3", &ExternalTestType1{})
 	s.InternalVersion = ""
-	s.MetaInsertionFactory = testMetaInsertionFactory{}
+	s.MetaFactory = testMetaFactory{}
 	return s
 }
 
-type testMetaInsertionFactory struct {
-	MyWeirdCustomEmbeddedVersionKindField struct {
+type testMetaFactory struct{}
+
+func (testMetaFactory) Interpret(data []byte) (version, kind string, err error) {
+	findKind := struct {
 		APIVersion string `json:"myVersionKey,omitempty" yaml:"myVersionKey,omitempty"`
 		ObjectKind string `json:"myKindKey,omitempty" yaml:"myKindKey,omitempty"`
-	} `json:",inline" yaml:",inline"`
+	}{}
+	// yaml is a superset of json, so we use it to decode here. That way,
+	// we understand both.
+	err = yaml.Unmarshal(data, &findKind)
+	if err != nil {
+		return "", "", fmt.Errorf("couldn't get version/kind: %v", err)
+	}
+	return findKind.APIVersion, findKind.ObjectKind, nil
 }
 
-// Create returns a new testMetaInsertionFactory with the version and kind fields set.
-func (testMetaInsertionFactory) Create(version, kind string) interface{} {
-	m := testMetaInsertionFactory{}
-	m.MyWeirdCustomEmbeddedVersionKindField.APIVersion = version
-	m.MyWeirdCustomEmbeddedVersionKindField.ObjectKind = kind
-	return &m
-}
-
-// Interpret returns the version and kind information from in, which must be
-// a testMetaInsertionFactory pointer object.
-func (testMetaInsertionFactory) Interpret(in interface{}) (version, kind string) {
-	m := in.(*testMetaInsertionFactory)
-	return m.MyWeirdCustomEmbeddedVersionKindField.APIVersion, m.MyWeirdCustomEmbeddedVersionKindField.ObjectKind
+func (testMetaFactory) Update(version, kind string, obj interface{}) error {
+	return UpdateVersionAndKind(nil, "APIVersion", version, "ObjectKind", kind, obj)
 }
 
 func objDiff(a, b interface{}) string {
@@ -308,143 +308,3 @@ func TestBadJSONRejectionForSetInternalVersion(t *testing.T) {
 		t.Errorf("Kind is set but doesn't match the object type: %s", badJSONKindMismatch)
 	}
 }
-
-func TestMetaValues(t *testing.T) {
-	type InternalSimple struct {
-		Version    string `json:"version,omitempty" yaml:"version,omitempty"`
-		Kind       string `json:"kind,omitempty" yaml:"kind,omitempty"`
-		TestString string `json:"testString" yaml:"testString"`
-	}
-	type ExternalSimple struct {
-		Version    string `json:"version,omitempty" yaml:"version,omitempty"`
-		Kind       string `json:"kind,omitempty" yaml:"kind,omitempty"`
-		TestString string `json:"testString" yaml:"testString"`
-	}
-	s := NewScheme()
-	s.InternalVersion = ""
-	s.AddKnownTypeWithName("", "Simple", &InternalSimple{})
-	s.AddKnownTypeWithName("externalVersion", "Simple", &ExternalSimple{})
-
-	internalToExternalCalls := 0
-	externalToInternalCalls := 0
-
-	// Register functions to verify that scope.Meta() gets set correctly.
-	err := s.AddConversionFuncs(
-		func(in *InternalSimple, out *ExternalSimple, scope Scope) error {
-			if e, a := "", scope.Meta().SrcVersion; e != a {
-				t.Errorf("Expected '%v', got '%v'", e, a)
-			}
-			if e, a := "externalVersion", scope.Meta().DestVersion; e != a {
-				t.Errorf("Expected '%v', got '%v'", e, a)
-			}
-			scope.Convert(&in.TestString, &out.TestString, 0)
-			internalToExternalCalls++
-			return nil
-		},
-		func(in *ExternalSimple, out *InternalSimple, scope Scope) error {
-			if e, a := "externalVersion", scope.Meta().SrcVersion; e != a {
-				t.Errorf("Expected '%v', got '%v'", e, a)
-			}
-			if e, a := "", scope.Meta().DestVersion; e != a {
-				t.Errorf("Expected '%v', got '%v'", e, a)
-			}
-			scope.Convert(&in.TestString, &out.TestString, 0)
-			externalToInternalCalls++
-			return nil
-		},
-	)
-	if err != nil {
-		t.Errorf("unexpected error: %v", err)
-	}
-	simple := &InternalSimple{
-		TestString: "foo",
-	}
-
-	// Test Encode, Decode, and DecodeInto
-	data, err := s.EncodeToVersion(simple, "externalVersion")
-	obj2, err2 := s.Decode(data)
-	obj3 := &InternalSimple{}
-	err3 := s.DecodeInto(data, obj3)
-	if err != nil || err2 != nil {
-		t.Fatalf("Failure: '%v' '%v' '%v'", err, err2, err3)
-	}
-	if _, ok := obj2.(*InternalSimple); !ok {
-		t.Fatalf("Got wrong type")
-	}
-	if e, a := simple, obj2; !reflect.DeepEqual(e, a) {
-		t.Errorf("Expected:\n %#v,\n Got:\n %#v", e, a)
-	}
-	if e, a := simple, obj3; !reflect.DeepEqual(e, a) {
-		t.Errorf("Expected:\n %#v,\n Got:\n %#v", e, a)
-	}
-
-	// Test Convert
-	external := &ExternalSimple{}
-	err = s.Convert(simple, external)
-	if err != nil {
-		t.Errorf("Unexpected error: %v", err)
-	}
-	if e, a := simple.TestString, external.TestString; e != a {
-		t.Errorf("Expected %v, got %v", e, a)
-	}
-
-	// Encode and Convert should each have caused an increment.
-	if e, a := 2, internalToExternalCalls; e != a {
-		t.Errorf("Expected %v, got %v", e, a)
-	}
-	// Decode and DecodeInto should each have caused an increment.
-	if e, a := 2, externalToInternalCalls; e != a {
-		t.Errorf("Expected %v, got %v", e, a)
-	}
-}
-
-func TestMetaValuesUnregisteredConvert(t *testing.T) {
-	type InternalSimple struct {
-		Version    string `json:"version,omitempty" yaml:"version,omitempty"`
-		Kind       string `json:"kind,omitempty" yaml:"kind,omitempty"`
-		TestString string `json:"testString" yaml:"testString"`
-	}
-	type ExternalSimple struct {
-		Version    string `json:"version,omitempty" yaml:"version,omitempty"`
-		Kind       string `json:"kind,omitempty" yaml:"kind,omitempty"`
-		TestString string `json:"testString" yaml:"testString"`
-	}
-	s := NewScheme()
-	s.InternalVersion = ""
-	// We deliberately don't register the types.
-
-	internalToExternalCalls := 0
-
-	// Register functions to verify that scope.Meta() gets set correctly.
-	err := s.AddConversionFuncs(
-		func(in *InternalSimple, out *ExternalSimple, scope Scope) error {
-			if e, a := "unknown", scope.Meta().SrcVersion; e != a {
-				t.Errorf("Expected '%v', got '%v'", e, a)
-			}
-			if e, a := "unknown", scope.Meta().DestVersion; e != a {
-				t.Errorf("Expected '%v', got '%v'", e, a)
-			}
-			scope.Convert(&in.TestString, &out.TestString, 0)
-			internalToExternalCalls++
-			return nil
-		},
-	)
-	if err != nil {
-		t.Errorf("unexpected error: %v", err)
-	}
-
-	simple := &InternalSimple{TestString: "foo"}
-	external := &ExternalSimple{}
-	err = s.Convert(simple, external)
-	if err != nil {
-		t.Errorf("Unexpected error: %v", err)
-	}
-	if e, a := simple.TestString, external.TestString; e != a {
-		t.Errorf("Expected %v, got %v", e, a)
-	}
-
-	// Verify that our conversion handler got called.
-	if e, a := 1, internalToExternalCalls; e != a {
-		t.Errorf("Expected %v, got %v", e, a)
-	}
-}

pkg/runtime/scheme.go

@@ -145,7 +145,7 @@ func (self *Scheme) rawExtensionToEmbeddedObject(in *RawExtension, out *Embedded
 func NewScheme() *Scheme {
 	s := &Scheme{conversion.NewScheme()}
 	s.raw.InternalVersion = ""
-	s.raw.MetaInsertionFactory = metaInsertion{}
+	s.raw.MetaFactory = conversion.SimpleMetaFactory{BaseFields: []string{"TypeMeta"}, VersionField: "APIVersion", KindField: "Kind"}
 	s.raw.AddConversionFuncs(
 		s.embeddedObjectToRawExtension,
 		s.rawExtensionToEmbeddedObject,
@@ -339,28 +339,3 @@ func (s *Scheme) CopyOrDie(obj Object) Object {
 	}
 	return newObj
 }
-
-// metaInsertion implements conversion.MetaInsertionFactory, which lets the conversion
-// package figure out how to encode our object's types and versions. These fields are
-// located in our TypeMeta.
-type metaInsertion struct {
-	TypeMeta struct {
-		APIVersion string `json:"apiVersion,omitempty" yaml:"apiVersion,omitempty"`
-		Kind       string `json:"kind,omitempty" yaml:"kind,omitempty"`
-	} `json:",inline" yaml:",inline"`
-}
-
-// Create returns a new metaInsertion with the version and kind fields set.
-func (metaInsertion) Create(version, kind string) interface{} {
-	m := metaInsertion{}
-	m.TypeMeta.APIVersion = version
-	m.TypeMeta.Kind = kind
-	return &m
-}
-
-// Interpret returns the version and kind information from in, which must be
-// a metaInsertion pointer object.
-func (metaInsertion) Interpret(in interface{}) (version, kind string) {
-	m := in.(*metaInsertion)
-	return m.TypeMeta.APIVersion, m.TypeMeta.Kind
-}