expose discovery information on scalable resources

Kubernetes-commit: 65d0f188f68f6428ccc0a776adff496d972faa56

pkg/endpoints/installer.go

@@ -378,20 +378,8 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 		resourceKind = kind
 	}
 
-	var shortNames []string
-	shortNamesProvider, ok := storage.(rest.ShortNamesProvider)
-	if ok {
-		shortNames = shortNamesProvider.ShortNames()
-	}
-
 	tableProvider, _ := storage.(rest.TableConvertor)
 
-	var categories []string
-	categoriesProvider, ok := storage.(rest.CategoriesProvider)
-	if ok {
-		categories = categoriesProvider.Categories()
-	}
-
 	var apiResource metav1.APIResource
 	// Get the list of actions for the given scope.
 	switch scope.Name() {
@@ -867,8 +855,19 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 		apiResource.Verbs = append(apiResource.Verbs, kubeVerb)
 	}
 	sort.Strings(apiResource.Verbs)
-	apiResource.ShortNames = shortNames
-	apiResource.Categories = categories
+
+	if shortNamesProvider, ok := storage.(rest.ShortNamesProvider); ok {
+		apiResource.ShortNames = shortNamesProvider.ShortNames()
+	}
+	if categoriesProvider, ok := storage.(rest.CategoriesProvider); ok {
+		apiResource.Categories = categoriesProvider.Categories()
+	}
+	if gvkProvider, ok := storage.(rest.GroupVersionKindProvider); ok {
+		gvk := gvkProvider.GroupVersionKind()
+		apiResource.Group = gvk.Group
+		apiResource.Version = gvk.Version
+		apiResource.Kind = gvk.Kind
+	}
 
 	return &apiResource, nil
 }

pkg/registry/rest/rest.go

@@ -77,6 +77,14 @@ type CategoriesProvider interface {
 	Categories() []string
 }
 
+// GroupVersionKindProvider is used to specify a particular GroupVersionKind to discovery.  This is used for polymorphic endpoints
+// which generally point to foreign versions.  Scale refers to Scale.v1beta1.extensions for instance.
+// This trumps KindProvider since it is capable of providing the information required.
+// TODO KindProvider (only used by federation) should be removed and replaced with this, but that presents greater risk late in 1.8.
+type GroupVersionKindProvider interface {
+	GroupVersionKind() schema.GroupVersionKind
+}
+
 // Lister is an object that can retrieve resources that match the provided field and label criteria.
 type Lister interface {
 	// NewList returns an empty object that can be used with the List call.