Add Object type to runtime, make runtime test pass.

pkg/api/register.go

@@ -21,21 +21,21 @@ import (
 )
 
 func init() {
-	runtime.AddKnownTypes("",
+	runtime.DefaultScheme.AddKnownTypes("",
-		PodList{},
+		&PodList{},
-		Pod{},
+		&Pod{},
-		ReplicationControllerList{},
+		&ReplicationControllerList{},
-		ReplicationController{},
+		&ReplicationController{},
-		ServiceList{},
+		&ServiceList{},
-		Service{},
+		&Service{},
-		MinionList{},
+		&MinionList{},
-		Minion{},
+		&Minion{},
-		Status{},
+		&Status{},
-		ServerOpList{},
+		&ServerOpList{},
-		ServerOp{},
+		&ServerOp{},
-		ContainerManifestList{},
+		&ContainerManifestList{},
-		Endpoints{},
+		&Endpoints{},
-		EndpointsList{},
+		&EndpointsList{},
-		Binding{},
+		&Binding{},
 	)
 }

pkg/api/types.go

@@ -65,6 +65,8 @@ type ContainerManifestList struct {
 	Items    []ContainerManifest `json:"items,omitempty" yaml:"items,omitempty"`
 }
 
+func (*ContainerManifestList) IsAnAPIObject() {}
+
 // Volume represents a named volume in a pod that may be accessed by any containers in the pod.
 type Volume struct {
 	// Required: This must be a DNS_LABEL.  Each volume in a pod must have
@@ -287,6 +289,8 @@ type PodList struct {
 	Items    []Pod `json:"items" yaml:"items,omitempty"`
 }
 
+func (*PodList) IsAnAPIObject() {}
+
 // Pod is a collection of containers, used as either input (create, update) or as output (list, get).
 type Pod struct {
 	JSONBase     `json:",inline" yaml:",inline"`
@@ -295,6 +299,8 @@ type Pod struct {
 	CurrentState PodState          `json:"currentState,omitempty" yaml:"currentState,omitempty"`
 }
 
+func (*Pod) IsAnAPIObject() {}
+
 // ReplicationControllerState is the state of a replication controller, either input (create, update) or as output (list, get).
 type ReplicationControllerState struct {
 	Replicas        int               `json:"replicas" yaml:"replicas"`
@@ -308,6 +314,8 @@ type ReplicationControllerList struct {
 	Items    []ReplicationController `json:"items,omitempty" yaml:"items,omitempty"`
 }
 
+func (*ReplicationControllerList) IsAnAPIObject() {}
+
 // ReplicationController represents the configuration of a replication controller.
 type ReplicationController struct {
 	JSONBase     `json:",inline" yaml:",inline"`
@@ -315,6 +323,8 @@ type ReplicationController struct {
 	Labels       map[string]string          `json:"labels,omitempty" yaml:"labels,omitempty"`
 }
 
+func (*ReplicationController) IsAnAPIObject() {}
+
 // PodTemplate holds the information used for creating pods.
 type PodTemplate struct {
 	DesiredState PodState          `json:"desiredState,omitempty" yaml:"desiredState,omitempty"`
@@ -327,6 +337,8 @@ type ServiceList struct {
 	Items    []Service `json:"items" yaml:"items"`
 }
 
+func (*ServiceList) IsAnAPIObject() {}
+
 // Service is a named abstraction of software service (for example, mysql) consisting of local port
 // (for example 3306) that the proxy listens on, and the selector that determines which pods
 // will answer requests sent through the proxy.
@@ -346,6 +358,8 @@ type Service struct {
 	ContainerPort util.IntOrString `json:"containerPort,omitempty" yaml:"containerPort,omitempty"`
 }
 
+func (*Service) IsAnAPIObject() {}
+
 // Endpoints is a collection of endpoints that implement the actual service, for example:
 // Name: "mysql", Endpoints: ["10.10.1.1:1909", "10.10.2.2:8834"]
 type Endpoints struct {
@@ -353,12 +367,16 @@ type Endpoints struct {
 	Endpoints []string `json:"endpoints,omitempty" yaml:"endpoints,omitempty"`
 }
 
+func (*Endpoints) IsAnAPIObject() {}
+
 // EndpointsList is a list of endpoints.
 type EndpointsList struct {
 	JSONBase `json:",inline" yaml:",inline"`
 	Items    []Endpoints `json:"items,omitempty" yaml:"items,omitempty"`
 }
 
+func (*EndpointsList) IsAnAPIObject() {}
+
 // Minion is a worker node in Kubernetenes.
 // The name of the minion according to etcd is in JSONBase.ID.
 type Minion struct {
@@ -367,12 +385,16 @@ type Minion struct {
 	HostIP string `json:"hostIP,omitempty" yaml:"hostIP,omitempty"`
 }
 
+func (*Minion) IsAnAPIObject() {}
+
 // MinionList is a list of minions.
 type MinionList struct {
 	JSONBase `json:",inline" yaml:",inline"`
 	Items    []Minion `json:"items,omitempty" yaml:"items,omitempty"`
 }
 
+func (*MinionList) IsAnAPIObject() {}
+
 // Binding is written by a scheduler to cause a pod to be bound to a host.
 type Binding struct {
 	JSONBase `json:",inline" yaml:",inline"`
@@ -380,6 +402,8 @@ type Binding struct {
 	Host     string `json:"host" yaml:"host"`
 }
 
+func (*Binding) IsAnAPIObject() {}
+
 // Status is a return value for calls that don't return other objects.
 // TODO: this could go in apiserver, but I'm including it here so clients needn't
 // import both.
@@ -403,6 +427,8 @@ type Status struct {
 	Code int `json:"code,omitempty" yaml:"code,omitempty"`
 }
 
+func (*Status) IsAnAPIObject() {}
+
 // StatusDetails is a set of additional properties that MAY be set by the
 // server to provide additional information about a response. The Reason
 // field of a Status object defines what attributes will be set. Clients
@@ -539,12 +565,16 @@ type ServerOp struct {
 	JSONBase `yaml:",inline" json:",inline"`
 }
 
+func (*ServerOp) IsAnAPIObject() {}
+
 // ServerOpList is a list of operations, as delivered to API clients.
 type ServerOpList struct {
 	JSONBase `yaml:",inline" json:",inline"`
 	Items    []ServerOp `yaml:"items,omitempty" json:"items,omitempty"`
 }
 
+func (*ServerOpList) IsAnAPIObject() {}
+
 // WatchEvent objects are streamed from the api server in response to a watch request.
 type WatchEvent struct {
 	// The type of the watch event; added, modified, or deleted.

pkg/api/v1beta1/conversion.go

@@ -24,7 +24,7 @@ import (
 )
 
 func init() {
-	runtime.AddConversionFuncs(
+	runtime.DefaultScheme.AddConversionFuncs(
 		// EnvVar's Key is deprecated in favor of Name.
 		func(in *newer.EnvVar, out *EnvVar, s conversion.Scope) error {
 			out.Value = in.Value

pkg/api/v1beta1/register.go

@@ -21,21 +21,21 @@ import (
 )
 
 func init() {
-	runtime.AddKnownTypes("v1beta1",
+	runtime.DefaultScheme.AddKnownTypes("v1beta1",
-		PodList{},
+		&PodList{},
-		Pod{},
+		&Pod{},
-		ReplicationControllerList{},
+		&ReplicationControllerList{},
-		ReplicationController{},
+		&ReplicationController{},
-		ServiceList{},
+		&ServiceList{},
-		Service{},
+		&Service{},
-		MinionList{},
+		&MinionList{},
-		Minion{},
+		&Minion{},
-		Status{},
+		&Status{},
-		ServerOpList{},
+		&ServerOpList{},
-		ServerOp{},
+		&ServerOp{},
-		ContainerManifestList{},
+		&ContainerManifestList{},
-		Endpoints{},
+		&Endpoints{},
-		EndpointsList{},
+		&EndpointsList{},
-		Binding{},
+		&Binding{},
 	)
 }

pkg/api/v1beta1/types.go

@@ -65,6 +65,8 @@ type ContainerManifestList struct {
 	Items    []ContainerManifest `json:"items,omitempty" yaml:"items,omitempty"`
 }
 
+func (*ContainerManifestList) IsAnAPIObject() {}
+
 // Volume represents a named volume in a pod that may be accessed by any containers in the pod.
 type Volume struct {
 	// Required: This must be a DNS_LABEL.  Each volume in a pod must have
@@ -243,6 +245,8 @@ type JSONBase struct {
 	APIVersion        string    `json:"apiVersion,omitempty" yaml:"apiVersion,omitempty"`
 }
 
+func (*JSONBase) IsAnAPIObject() {}
+
 // PodStatus represents a status of a pod.
 type PodStatus string
 
@@ -298,6 +302,8 @@ type PodList struct {
 	Items    []Pod `json:"items" yaml:"items,omitempty"`
 }
 
+func (*PodList) IsAnAPIObject() {}
+
 // Pod is a collection of containers, used as either input (create, update) or as output (list, get).
 type Pod struct {
 	JSONBase     `json:",inline" yaml:",inline"`
@@ -306,6 +312,8 @@ type Pod struct {
 	CurrentState PodState          `json:"currentState,omitempty" yaml:"currentState,omitempty"`
 }
 
+func (*Pod) IsAnAPIObject() {}
+
 // ReplicationControllerState is the state of a replication controller, either input (create, update) or as output (list, get).
 type ReplicationControllerState struct {
 	Replicas        int               `json:"replicas" yaml:"replicas"`
@@ -319,6 +327,8 @@ type ReplicationControllerList struct {
 	Items    []ReplicationController `json:"items,omitempty" yaml:"items,omitempty"`
 }
 
+func (*ReplicationControllerList) IsAnAPIObject() {}
+
 // ReplicationController represents the configuration of a replication controller.
 type ReplicationController struct {
 	JSONBase     `json:",inline" yaml:",inline"`
@@ -326,6 +336,8 @@ type ReplicationController struct {
 	Labels       map[string]string          `json:"labels,omitempty" yaml:"labels,omitempty"`
 }
 
+func (*ReplicationController) IsAnAPIObject() {}
+
 // PodTemplate holds the information used for creating pods.
 type PodTemplate struct {
 	DesiredState PodState          `json:"desiredState,omitempty" yaml:"desiredState,omitempty"`
@@ -338,6 +350,8 @@ type ServiceList struct {
 	Items    []Service `json:"items" yaml:"items"`
 }
 
+func (*ServiceList) IsAnAPIObject() {}
+
 // Service is a named abstraction of software service (for example, mysql) consisting of local port
 // (for example 3306) that the proxy listens on, and the selector that determines which pods
 // will answer requests sent through the proxy.
@@ -357,6 +371,8 @@ type Service struct {
 	ContainerPort util.IntOrString `json:"containerPort,omitempty" yaml:"containerPort,omitempty"`
 }
 
+func (*Service) IsAnAPIObject() {}
+
 // Endpoints is a collection of endpoints that implement the actual service, for example:
 // Name: "mysql", Endpoints: ["10.10.1.1:1909", "10.10.2.2:8834"]
 type Endpoints struct {
@@ -364,12 +380,16 @@ type Endpoints struct {
 	Endpoints []string `json:"endpoints,omitempty" yaml:"endpoints,omitempty"`
 }
 
+func (*Endpoints) IsAnAPIObject() {}
+
 // EndpointsList is a list of endpoints.
 type EndpointsList struct {
 	JSONBase `json:",inline" yaml:",inline"`
 	Items    []Endpoints `json:"items,omitempty" yaml:"items,omitempty"`
 }
 
+func (*EndpointsList) IsAnAPIObject() {}
+
 // Minion is a worker node in Kubernetenes.
 // The name of the minion according to etcd is in JSONBase.ID.
 type Minion struct {
@@ -378,6 +398,8 @@ type Minion struct {
 	HostIP string `json:"hostIP,omitempty" yaml:"hostIP,omitempty"`
 }
 
+func (*Minion) IsAnAPIObject() {}
+
 // MinionList is a list of minions.
 type MinionList struct {
 	JSONBase `json:",inline" yaml:",inline"`
@@ -387,6 +409,8 @@ type MinionList struct {
 	Items   []Minion `json:"items,omitempty" yaml:"items,omitempty"`
 }
 
+func (*MinionList) IsAnAPIObject() {}
+
 // Binding is written by a scheduler to cause a pod to be bound to a host.
 type Binding struct {
 	JSONBase `json:",inline" yaml:",inline"`
@@ -394,6 +418,8 @@ type Binding struct {
 	Host     string `json:"host" yaml:"host"`
 }
 
+func (*Binding) IsAnAPIObject() {}
+
 // Status is a return value for calls that don't return other objects.
 // TODO: this could go in apiserver, but I'm including it here so clients needn't
 // import both.
@@ -417,6 +443,8 @@ type Status struct {
 	Code int `json:"code,omitempty" yaml:"code,omitempty"`
 }
 
+func (*Status) IsAnAPIObject() {}
+
 // StatusDetails is a set of additional properties that MAY be set by the
 // server to provide additional information about a response. The Reason
 // field of a Status object defines what attributes will be set. Clients
@@ -540,12 +568,16 @@ type ServerOp struct {
 	JSONBase `yaml:",inline" json:",inline"`
 }
 
+func (*ServerOp) IsAnAPIObject() {}
+
 // ServerOpList is a list of operations, as delivered to API clients.
 type ServerOpList struct {
 	JSONBase `yaml:",inline" json:",inline"`
 	Items    []ServerOp `yaml:"items,omitempty" json:"items,omitempty"`
 }
 
+func (*ServerOpList) IsAnAPIObject() {}
+
 // WatchEvent objects are streamed from the api server in response to a watch request.
 type WatchEvent struct {
 	// The type of the watch event; added, modified, or deleted.

pkg/runtime/embedded.go

@@ -33,7 +33,7 @@ func (a *EmbeddedObject) UnmarshalJSON(b []byte) error {
 		return nil
 	}
 
-	obj, err := Decode(b)
+	obj, err := Codec.Decode(b)
 	if err != nil {
 		return err
 	}
@@ -48,7 +48,7 @@ func (a EmbeddedObject) MarshalJSON() ([]byte, error) {
 		return []byte("null"), nil
 	}
 
-	return Encode(a.Object)
+	return Codec.Encode(a.Object)
 }
 
 // SetYAML implements the yaml.Setter interface.
@@ -67,7 +67,7 @@ func (a *EmbeddedObject) SetYAML(tag string, value interface{}) bool {
 	if err != nil {
 		panic("yaml can't reverse its own object")
 	}
-	obj, err := Decode(b)
+	obj, err := Codec.Decode(b)
 	if err != nil {
 		return false
 	}
@@ -82,7 +82,7 @@ func (a EmbeddedObject) GetYAML() (tag string, value interface{}) {
 		return
 	}
 	// Encode returns JSON, which is conveniently a subset of YAML.
-	v, err := Encode(a.Object)
+	v, err := Codec.Encode(a.Object)
 	if err != nil {
 		panic("impossible to encode API object!")
 	}

pkg/runtime/embedded_test.go

@@ -22,14 +22,19 @@ import (
 	"testing"
 )
 
-func TestEmbeddedObject(t *testing.T) {
 type EmbeddedTest struct {
 	JSONBase    `yaml:",inline" json:",inline"`
 	Object      EmbeddedObject `yaml:"object,omitempty" json:"object,omitempty"`
 	EmptyObject EmbeddedObject `yaml:"emptyObject,omitempty" json:"emptyObject,omitempty"`
 }
-	AddKnownTypes("", EmbeddedTest{})
+
-	AddKnownTypes("v1beta1", EmbeddedTest{})
+func (*EmbeddedTest) IsAnAPIObject() {}
+
+func TestEmbeddedObject(t *testing.T) {
+	// TODO(dbsmith) fix EmbeddedObject to not use DefaultScheme.
+	s := DefaultScheme
+	s.AddKnownTypes("", &EmbeddedTest{})
+	s.AddKnownTypes("v1beta1", &EmbeddedTest{})
 
 	outer := &EmbeddedTest{
 		JSONBase: JSONBase{ID: "outer"},
@@ -40,14 +45,14 @@ func TestEmbeddedObject(t *testing.T) {
 		},
 	}
 
-	wire, err := Encode(outer)
+	wire, err := s.Encode(outer)
 	if err != nil {
 		t.Fatalf("Unexpected encode error '%v'", err)
 	}
 
 	t.Logf("Wire format is:\n%v\n", string(wire))
 
-	decoded, err := Decode(wire)
+	decoded, err := s.Decode(wire)
 	if err != nil {
 		t.Fatalf("Unexpected decode error %v", err)
 	}

pkg/runtime/helper.go

@@ -27,38 +27,56 @@ import (
 // codec defines methods for serializing and deserializing API
 // objects.
 type codec interface {
-	Encode(obj interface{}) (data []byte, err error)
+	Encode(obj Object) (data []byte, err error)
-	Decode(data []byte) (interface{}, error)
+	Decode(data []byte) (Object, error)
-	DecodeInto(data []byte, obj interface{}) error
+	DecodeInto(data []byte, obj Object) error
 }
 
 // resourceVersioner provides methods for setting and retrieving
 // the resource version from an API object.
 type resourceVersioner interface {
-	SetResourceVersion(obj interface{}, version uint64) error
+	SetResourceVersion(obj Object, version uint64) error
-	ResourceVersion(obj interface{}) (uint64, error)
+	ResourceVersion(obj Object) (uint64, error)
 }
 
 var ResourceVersioner resourceVersioner = NewJSONBaseResourceVersioner()
-var conversionScheme = conversion.NewScheme()
+var DefaultScheme = NewScheme("", "v1beta1")
-var Codec codec = conversionScheme
+var Codec codec = DefaultScheme
 
-func init() {
+// Scheme defines methods for serializing and deserializing API objects. It
-	conversionScheme.InternalVersion = ""
+// is an adaptation of conversion's Scheme for our API objects.
-	conversionScheme.ExternalVersion = "v1beta1"
+type Scheme struct {
-	conversionScheme.MetaInsertionFactory = metaInsertion{}
+	raw *conversion.Scheme
+}
+
+// NewScheme creates a new Scheme. A default scheme is provided and accessible
+// as the "DefaultScheme" variable.
+func NewScheme(internalVersion, externalVersion string) *Scheme {
+	s := &Scheme{conversion.NewScheme()}
+	s.raw.InternalVersion = internalVersion
+	s.raw.ExternalVersion = externalVersion
+	s.raw.MetaInsertionFactory = metaInsertion{}
+	return s
 }
 
 // AddKnownTypes registers the types of the arguments to the marshaller of the package api.
 // Encode() refuses the object unless its type is registered with AddKnownTypes.
-func AddKnownTypes(version string, types ...interface{}) {
+func (s *Scheme) AddKnownTypes(version string, types ...Object) {
-	conversionScheme.AddKnownTypes(version, types...)
+	interfaces := make([]interface{}, len(types))
+	for i := range types {
+		interfaces[i] = types[i]
+	}
+	s.raw.AddKnownTypes(version, interfaces...)
 }
 
 // New returns a new API object of the given version ("" for internal
 // representation) and name, or an error if it hasn't been registered.
-func New(versionName, typeName string) (interface{}, error) {
+func (s *Scheme) New(versionName, typeName string) (Object, error) {
-	return conversionScheme.NewObject(versionName, typeName)
+	obj, err := s.raw.NewObject(versionName, typeName)
+	if err != nil {
+		return nil, err
+	}
+	return obj.(Object), nil
 }
 
 // AddConversionFuncs adds a function to the list of conversion functions. The given
@@ -73,20 +91,20 @@ func New(versionName, typeName string) (interface{}, error) {
 // sanely copy fields that have the same names. It's OK if the destination type has
 // extra fields, but it must not remove any. So you only need to add a conversion
 // function for things with changed/removed fields.
-func AddConversionFuncs(conversionFuncs ...interface{}) error {
+func (s *Scheme) AddConversionFuncs(conversionFuncs ...interface{}) error {
-	return conversionScheme.AddConversionFuncs(conversionFuncs...)
+	return s.raw.AddConversionFuncs(conversionFuncs...)
 }
 
-// Convert will attempt to convert in into out. Both must be pointers to API objects.
+// Convert will attempt to convert in into out. Both must be pointers.
 // For easy testing of conversion functions. Returns an error if the conversion isn't
 // possible.
-func Convert(in, out interface{}) error {
+func (s *Scheme) Convert(in, out interface{}) error {
-	return conversionScheme.Convert(in, out)
+	return s.raw.Convert(in, out)
 }
 
 // FindJSONBase takes an arbitary api type, returns pointer to its JSONBase field.
 // obj must be a pointer to an api type.
-func FindJSONBase(obj interface{}) (JSONBaseInterface, error) {
+func FindJSONBase(obj Object) (JSONBaseInterface, error) {
 	v, err := enforcePtr(obj)
 	if err != nil {
 		return nil, err
@@ -108,8 +126,8 @@ func FindJSONBase(obj interface{}) (JSONBaseInterface, error) {
 }
 
 // EncodeOrDie is a version of Encode which will panic instead of returning an error. For tests.
-func EncodeOrDie(obj interface{}) string {
+func (s *Scheme) EncodeOrDie(obj Object) string {
-	return conversionScheme.EncodeOrDie(obj)
+	return s.raw.EncodeOrDie(obj)
 }
 
 // Encode turns the given api object into an appropriate JSON string.
@@ -146,14 +164,14 @@ func EncodeOrDie(obj interface{}) string {
 // default will be needed, to allow operating in clusters that haven't yet
 // upgraded.
 //
-func Encode(obj interface{}) (data []byte, err error) {
+func (s *Scheme) Encode(obj Object) (data []byte, err error) {
-	return conversionScheme.Encode(obj)
+	return s.raw.Encode(obj)
 }
 
 // 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) {
+func enforcePtr(obj Object) (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())
@@ -181,8 +199,12 @@ func VersionAndKind(data []byte) (version, kind string, err error) {
 // Deduces the type based upon the APIVersion and Kind fields, which are set
 // by Encode. Only versioned objects (APIVersion != "") are accepted. The object
 // will be converted into the in-memory unversioned type before being returned.
-func Decode(data []byte) (interface{}, error) {
+func (s *Scheme) Decode(data []byte) (Object, error) {
-	return conversionScheme.Decode(data)
+	obj, err := s.raw.Decode(data)
+	if err != nil {
+		return nil, err
+	}
+	return obj.(Object), nil
 }
 
 // DecodeInto parses a YAML or JSON string and stores it in obj. Returns an error
@@ -190,22 +212,22 @@ func Decode(data []byte) (interface{}, error) {
 // pointer to an api type.
 // If obj's APIVersion doesn't match that in data, an attempt will be made to convert
 // data into obj's version.
-func DecodeInto(data []byte, obj interface{}) error {
+func (s *Scheme) DecodeInto(data []byte, obj Object) error {
-	return conversionScheme.DecodeInto(data, obj)
+	return s.raw.DecodeInto(data, obj)
 }
 
 // Does a deep copy of an API object.  Useful mostly for tests.
 // TODO(dbsmith): implement directly instead of via Encode/Decode
-func Copy(obj interface{}) (interface{}, error) {
+func (s *Scheme) Copy(obj Object) (Object, error) {
-	data, err := Encode(obj)
+	data, err := s.Encode(obj)
 	if err != nil {
 		return nil, err
 	}
-	return Decode(data)
+	return s.Decode(data)
 }
 
-func CopyOrDie(obj interface{}) interface{} {
+func (s *Scheme) CopyOrDie(obj Object) Object {
-	newObj, err := Copy(obj)
+	newObj, err := s.Copy(obj)
 	if err != nil {
 		panic(err)
 	}

pkg/runtime/helper_test.go

@@ -25,31 +25,13 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
 )
 
-func TestEncode_NonPtr(t *testing.T) {
+func TestEncode(t *testing.T) {
-	pod := api.Pod{
-		Labels: map[string]string{"name": "foo"},
-	}
-	obj := interface{}(pod)
-	data, err := runtime.Encode(obj)
-	obj2, err2 := runtime.Decode(data)
-	if err != nil || err2 != nil {
-		t.Fatalf("Failure: '%v' '%v'", err, err2)
-	}
-	if _, ok := obj2.(*api.Pod); !ok {
-		t.Fatalf("Got wrong type")
-	}
-	if !reflect.DeepEqual(obj2, &pod) {
-		t.Errorf("Expected:\n %#v,\n Got:\n %#v", &pod, obj2)
-	}
-}
-
-func TestEncode_Ptr(t *testing.T) {
 	pod := &api.Pod{
 		Labels: map[string]string{"name": "foo"},
 	}
-	obj := interface{}(pod)
+	obj := runtime.Object(pod)
-	data, err := runtime.Encode(obj)
+	data, err := runtime.DefaultScheme.Encode(obj)
-	obj2, err2 := runtime.Decode(data)
+	obj2, err2 := runtime.DefaultScheme.Decode(data)
 	if err != nil || err2 != nil {
 		t.Fatalf("Failure: '%v' '%v'", err, err2)
 	}
@@ -63,11 +45,11 @@ func TestEncode_Ptr(t *testing.T) {
 
 func TestBadJSONRejection(t *testing.T) {
 	badJSONMissingKind := []byte(`{ }`)
-	if _, err := runtime.Decode(badJSONMissingKind); err == nil {
+	if _, err := runtime.DefaultScheme.Decode(badJSONMissingKind); err == nil {
 		t.Errorf("Did not reject despite lack of kind field: %s", badJSONMissingKind)
 	}
 	badJSONUnknownType := []byte(`{"kind": "bar"}`)
-	if _, err1 := runtime.Decode(badJSONUnknownType); err1 == nil {
+	if _, err1 := runtime.DefaultScheme.Decode(badJSONUnknownType); err1 == nil {
 		t.Errorf("Did not reject despite use of unknown type: %s", badJSONUnknownType)
 	}
 	/*badJSONKindMismatch := []byte(`{"kind": "Pod"}`)

pkg/runtime/jsonbase.go

@@ -29,7 +29,7 @@ func NewJSONBaseResourceVersioner() resourceVersioner {
 
 type jsonBaseResourceVersioner struct{}
 
-func (v jsonBaseResourceVersioner) ResourceVersion(obj interface{}) (uint64, error) {
+func (v jsonBaseResourceVersioner) ResourceVersion(obj Object) (uint64, error) {
 	json, err := FindJSONBase(obj)
 	if err != nil {
 		return 0, err
@@ -37,7 +37,7 @@ func (v jsonBaseResourceVersioner) ResourceVersion(obj interface{}) (uint64, err
 	return json.ResourceVersion(), nil
 }
 
-func (v jsonBaseResourceVersioner) SetResourceVersion(obj interface{}, version uint64) error {
+func (v jsonBaseResourceVersioner) SetResourceVersion(obj Object, version uint64) error {
 	json, err := FindJSONBase(obj)
 	if err != nil {
 		return err

pkg/runtime/jsonbase_test.go

@@ -77,20 +77,20 @@ func TestGenericJSONBase(t *testing.T) {
 	}
 }
 
-func TestResourceVersionerOfAPI(t *testing.T) {
-	type JSONBase struct {
-		Kind              string    `json:"kind,omitempty" yaml:"kind,omitempty"`
-		ID                string    `json:"id,omitempty" yaml:"id,omitempty"`
-		CreationTimestamp util.Time `json:"creationTimestamp,omitempty" yaml:"creationTimestamp,omitempty"`
-		SelfLink          string    `json:"selfLink,omitempty" yaml:"selfLink,omitempty"`
-		ResourceVersion   uint64    `json:"resourceVersion,omitempty" yaml:"resourceVersion,omitempty"`
-		APIVersion        string    `json:"apiVersion,omitempty" yaml:"apiVersion,omitempty"`
-	}
 type MyAPIObject struct {
 	JSONBase `yaml:",inline" json:",inline"`
 }
+
+func (*MyAPIObject) IsAnAPIObject() {}
+
+type MyIncorrectlyMarkedAsAPIObject struct {
+}
+
+func (*MyIncorrectlyMarkedAsAPIObject) IsAnAPIObject() {}
+
+func TestResourceVersionerOfAPI(t *testing.T) {
 	type T struct {
-		Object   interface{}
+		Object
 		Expected uint64
 	}
 	testCases := map[string]T{
@@ -110,10 +110,10 @@ func TestResourceVersionerOfAPI(t *testing.T) {
 	}
 
 	failingCases := map[string]struct {
-		Object   interface{}
+		Object
 		Expected uint64
 	}{
-		"not a valid object to try": {JSONBase{ResourceVersion: 1}, 1},
+		"not a valid object to try": {&MyIncorrectlyMarkedAsAPIObject{}, 1},
 	}
 	for key, testCase := range failingCases {
 		_, err := versioning.ResourceVersion(testCase.Object)
@@ -123,7 +123,7 @@ func TestResourceVersionerOfAPI(t *testing.T) {
 	}
 
 	setCases := map[string]struct {
-		Object   interface{}
+		Object
 		Expected uint64
 	}{
 		"pointer to api object with version": {&MyAPIObject{JSONBase: JSONBase{ResourceVersion: 1}}, 1},
@@ -140,17 +140,4 @@ func TestResourceVersionerOfAPI(t *testing.T) {
 			t.Errorf("%s: expected %d, got %d", key, 5, actual)
 		}
 	}
-
-	failingSetCases := map[string]struct {
-		Object   interface{}
-		Expected uint64
-	}{
-		"empty api object":        {MyAPIObject{}, 0},
-		"api object with version": {MyAPIObject{JSONBase: JSONBase{ResourceVersion: 1}}, 1},
-	}
-	for key, testCase := range failingSetCases {
-		if err := versioning.SetResourceVersion(testCase.Object, 5); err == nil {
-			t.Errorf("%s: unexpected non-error", key)
-		}
-	}
 }

pkg/runtime/types.go

@@ -20,6 +20,15 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 )
 
+// All api types must support the Object interface. It's deliberately tiny so that this is not an onerous
+// burden. Implement it with a pointer reciever; this will allow us to use the go compiler to check the
+// one thing about our objects that it's capable of checking for us.
+type Object interface {
+	// This function is used only to enforce membership. It's never called.
+	// TODO: Consider mass rename in the future to make it do something useful.
+	IsAnAPIObject()
+}
+
 // Note that the types provided in this file are not versioned and are intended to be
 // safe to use from within all versions of every API object.
 
@@ -29,8 +38,9 @@ import (
 // 	runtime.JSONBase    `yaml:",inline" json:",inline"`
 // 	... // other fields
 // }
+// func (*MyAwesomeAPIObject) IsAnAPIObject() {}
 //
-// JSONBase is provided here for convenience. You may use it directlly from this package or define
+// JSONBase is provided here for convenience. You may use it directly from this package or define
 // your own with the same fields.
 //
 type JSONBase struct {
@@ -43,17 +53,16 @@ type JSONBase struct {
 }
 
 // EmbeddedObject has appropriate encoder and decoder functions, such that on the wire, it's
-// stored as a []byte, but in memory, the contained object is accessable as an interface{}
+// stored as a []byte, but in memory, the contained object is accessable as an Object
-// via the Get() function. Only objects having a JSONBase may be stored via Object.
+// via the Get() function. Only valid API objects may be stored via EmbeddedObject.
 // The purpose of this is to allow an API object of type known only at runtime to be
 // embedded within other API objects.
 //
 // Note that object assumes that you've registered all of your api types with the api package.
 //
-// Note that objects will be serialized into the api package's default external versioned type;
+// TODO(dbsmith): Stop using runtime.Codec, use the codec appropriate for the conversion (I have a plan).
-// this should be fixed in the future to use the version of the current Codec instead.
 type EmbeddedObject struct {
-	Object interface{}
+	Object
 }
 
 // Extension allows api objects with unknown types to be passed-through. This can be used
@@ -61,4 +70,8 @@ type EmbeddedObject struct {
 // JSONBase features-- kind, version, resourceVersion, etc.
 // TODO: Not implemented yet
 type Extension struct {
+	JSONBase `yaml:",inline" json:",inline"`
+	// RawJSON to go here.
 }
+
+func (*Extension) IsAnAPIObject() {}