Add GetReference()

pkg/api/ref.go

@@ -0,0 +1,52 @@
+/*
+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 api
+
+import (
+	"fmt"
+	"regexp"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
+)
+
+var versionFromSelfLink = regexp.MustCompile("/api/([^/]*)/")
+
+// GetReference returns an ObjectReference which refers to the given
+// object, or an error if the object doesn't follow the conventions
+// that would allow this.
+func GetReference(obj runtime.Object) (*ObjectReference, error) {
+	jsonBase, err := runtime.FindJSONBase(obj)
+	if err != nil {
+		return nil, err
+	}
+	_, kind, err := Scheme.ObjectVersionAndKind(obj)
+	if err != nil {
+		return nil, err
+	}
+	version := versionFromSelfLink.FindStringSubmatch(jsonBase.SelfLink())
+	if len(version) < 2 {
+		return nil, fmt.Errorf("unexpected self link format: %v", jsonBase.SelfLink())
+	}
+	return &ObjectReference{
+		Kind:       kind,
+		APIVersion: version[1],
+		// TODO: correct Name and UID when JSONBase makes a distinction
+		Name:            jsonBase.ID(),
+		UID:             jsonBase.ID(),
+		ResourceVersion: jsonBase.ResourceVersion(),
+	}, nil
+}

pkg/api/ref_test.go

@@ -0,0 +1,95 @@
+/*
+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 api
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
+)
+
+type FakeAPIObject struct{}
+
+func (*FakeAPIObject) IsAnAPIObject() {}
+
+func TestGetReference(t *testing.T) {
+	table := map[string]struct {
+		obj       runtime.Object
+		ref       *ObjectReference
+		shouldErr bool
+	}{
+		"pod": {
+			obj: &Pod{
+				JSONBase: JSONBase{
+					ID:              "foo",
+					ResourceVersion: 42,
+					SelfLink:        "/api/v1beta1/pods/foo",
+				},
+			},
+			ref: &ObjectReference{
+				Kind:            "Pod",
+				APIVersion:      "v1beta1",
+				Name:            "foo",
+				UID:             "foo",
+				ResourceVersion: 42,
+			},
+		},
+		"serviceList": {
+			obj: &ServiceList{
+				JSONBase: JSONBase{
+					ID:              "foo",
+					ResourceVersion: 42,
+					SelfLink:        "/api/v1beta2/services",
+				},
+			},
+			ref: &ObjectReference{
+				Kind:            "ServiceList",
+				APIVersion:      "v1beta2",
+				Name:            "foo",
+				UID:             "foo",
+				ResourceVersion: 42,
+			},
+		},
+		"badSelfLink": {
+			obj: &ServiceList{
+				JSONBase: JSONBase{
+					ID:              "foo",
+					ResourceVersion: 42,
+					SelfLink:        "v1beta2/services",
+				},
+			},
+			shouldErr: true,
+		},
+		"error": {
+			obj:       &FakeAPIObject{},
+			ref:       nil,
+			shouldErr: true,
+		},
+	}
+
+	for name, item := range table {
+		ref, err := GetReference(item.obj)
+		if e, a := item.shouldErr, (err != nil); e != a {
+			t.Errorf("%v: expected %v, got %v", name, e, a)
+			continue
+		}
+		if e, a := item.ref, ref; !reflect.DeepEqual(e, a) {
+			t.Errorf("%v: expected %#v, got %#v", name, e, a)
+		}
+	}
+}

pkg/runtime/scheme.go

@@ -198,10 +198,17 @@ func (s *Scheme) AddKnownTypeWithName(version, kind string, obj Object) {
 	s.raw.AddKnownTypeWithName(version, kind, obj)
 }
 
+// KnownTypes returns the types known for the given version.
+// Return value must be treated as read-only.
 func (s *Scheme) KnownTypes(version string) map[string]reflect.Type {
 	return s.raw.KnownTypes(version)
 }
 
+// ObjectVersionAndKind returns the version and kind of the given Object.
+func (s *Scheme) ObjectVersionAndKind(obj Object) (version, kind string, err error) {
+	return s.raw.ObjectVersionAndKind(obj)
+}
+
 // 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 (s *Scheme) New(versionName, typeName string) (Object, error) {