revised status subresource interface

Author: droot

pkg/client/client.go

@@ -110,24 +110,6 @@ func (c *client) Update(ctx context.Context, obj runtime.Object) error {
 		Into(obj)
 }
 
-// UpdateStatus implements client.Client
-func (c *client) UpdateStatus(ctx context.Context, obj runtime.Object) error {
-	o, err := c.cache.getObjMeta(obj)
-	if err != nil {
-		return err
-	}
-	// TODO(droot): examine the returned error and check if it error needs to be
-	// wrapped to improve the UX ?
-	return o.Put().
-		NamespaceIfScoped(o.GetNamespace(), o.isNamespaced()).
-		Resource(o.resource()).
-		Name(o.GetName()).
-		SubResource("status").
-		Body(obj).
-		Do().
-		Into(obj)
-}
-
 // Delete implements client.Client
 func (c *client) Delete(ctx context.Context, obj runtime.Object) error {
 	o, err := c.cache.getObjMeta(obj)
@@ -172,3 +154,36 @@ func (c *client) List(ctx context.Context, opts *ListOptions, obj runtime.Object
 		Do().
 		Into(obj)
 }
+
+// Status returns client.StatusClient
+func (c *client) Status() StatusWriter {
+	return &statusWriter{client: c}
+}
+
+// statusWriter is client.StatusWriter that writes status subresource
+type statusWriter struct {
+	client *client
+}
+
+// ensure statusWriter implements client.StatusWriter
+var _ StatusWriter = &statusWriter{}
+
+// Update implements client.StatusWriter
+func (sw *statusWriter) Update(_ context.Context, obj runtime.Object) error {
+	o, err := sw.client.cache.getObjMeta(obj)
+	if err != nil {
+		return err
+	}
+	// TODO(droot): examine the returned error and check if it error needs to be
+	// wrapped to improve the UX ?
+	// It will be nice to receive an error saying the object doesn't implement
+	// status subresource and check CRD definition
+	return o.Put().
+		NamespaceIfScoped(o.GetNamespace(), o.isNamespaced()).
+		Resource(o.resource()).
+		Name(o.GetName()).
+		SubResource("status").
+		Body(obj).
+		Do().
+		Into(obj)
+}

pkg/client/client_test.go

@@ -393,7 +393,7 @@ var _ = Describe("Client", func() {
 		})
 	})
 
-	Describe("UpdateStatus", func() {
+	Describe("StatusClient", func() {
 		It("should update status of an existing object", func(done Done) {
 			cl, err := client.New(cfg, client.Options{})
 			Expect(err).NotTo(HaveOccurred())
@@ -405,7 +405,7 @@ var _ = Describe("Client", func() {
 
 			By("updating the status of Deployment")
 			dep.Status.Replicas = 1
-			err = cl.UpdateStatus(context.TODO(), dep)
+			err = cl.Status().Update(context.TODO(), dep)
 			Expect(err).NotTo(HaveOccurred())
 
 			By("validating updated Deployment has new status")
@@ -430,7 +430,7 @@ var _ = Describe("Client", func() {
 			var rc int32 = 1
 			dep.Status.Replicas = 1
 			dep.Spec.Replicas = &rc
-			err = cl.UpdateStatus(context.TODO(), dep)
+			err = cl.Status().Update(context.TODO(), dep)
 			Expect(err).NotTo(HaveOccurred())
 
 			By("validating updated Deployment has new status and unchanged spec")
@@ -453,7 +453,7 @@ var _ = Describe("Client", func() {
 
 			By("updating status of the object")
 			node.Status.Phase = corev1.NodeRunning
-			err = cl.UpdateStatus(context.TODO(), node)
+			err = cl.Status().Update(context.TODO(), node)
 			Expect(err).NotTo(HaveOccurred())
 
 			By("validate updated Node had new annotation")
@@ -471,7 +471,7 @@ var _ = Describe("Client", func() {
 			Expect(cl).NotTo(BeNil())
 
 			By("updating status of a non-existent object")
-			err = cl.UpdateStatus(context.TODO(), dep)
+			err = cl.Status().Update(context.TODO(), dep)
 			Expect(err).To(HaveOccurred())
 
 			close(done)
@@ -498,7 +498,7 @@ var _ = Describe("Client", func() {
 
 			By("updating status of the Deployment")
 			dep.Status.Replicas = 1
-			err = cl.UpdateStatus(context.TODO(), dep)
+			err = cl.Status().Update(context.TODO(), dep)
 			Expect(err).To(HaveOccurred())
 			Expect(err.Error()).To(ContainSubstring("no kind is registered for the type"))
 

pkg/client/fake/client.go

@@ -123,10 +123,8 @@ func (c *fakeClient) Update(ctx context.Context, obj runtime.Object) error {
 	return c.tracker.Update(gvr, obj, accessor.GetNamespace())
 }
 
-func (c *fakeClient) UpdateStatus(ctx context.Context, obj runtime.Object) error {
-	// TODO(droot): This results in full update of the obj (spec + status). Need
-	// a way to update status field only.
-	return c.Update(ctx, obj)
+func (c *fakeClient) Status() client.StatusWriter {
+	return &fakeStatusWriter{client: c}
 }
 
 func getGVRFromObject(obj runtime.Object) (schema.GroupVersionResource, error) {
@@ -137,3 +135,13 @@ func getGVRFromObject(obj runtime.Object) (schema.GroupVersionResource, error) {
 	gvr, _ := meta.UnsafeGuessKindToResource(gvk)
 	return gvr, nil
 }
+
+type fakeStatusWriter struct {
+	client *fakeClient
+}
+
+func (sw *fakeStatusWriter) Update(ctx context.Context, obj runtime.Object) error {
+	// TODO(droot): This results in full update of the obj (spec + status). Need
+	// a way to update status field only.
+	return sw.client.Update(ctx, obj)
+}

pkg/client/interfaces.go

@@ -55,17 +55,27 @@ type Writer interface {
 	// Update updates the given obj in the Kubernetes cluster. obj must be a
 	// struct pointer so that obj can be updated with the content returned by the Server.
 	Update(ctx context.Context, obj runtime.Object) error
+}
+
+// StatusClient knows how to create a client which can update status subresource
+// for kubernetes objects.
+type StatusClient interface {
+	Status() StatusWriter
+}
 
-	// UpdateStatus updates the fields corresponding to status subresource for
-	// the given obj. obj must be a struct pointer so that obj can be updated
+// StatusWriter knows how to update status subresource of a Kubernetes object.
+type StatusWriter interface {
+	// Update updates the fields corresponding to the status subresource for the
+	// given obj. obj must be a struct pointer so that obj can be updated
 	// with the content returned by the Server.
-	UpdateStatus(ctx context.Context, obj runtime.Object) error
+	Update(ctx context.Context, obj runtime.Object) error
 }
 
 // Client knows how to perform CRUD operations on Kubernetes objects.
 type Client interface {
 	Reader
 	Writer
+	StatusClient
 }
 
 // IndexerFunc knows how to take an object and turn it into a series

pkg/client/split.go

@@ -17,9 +17,10 @@ limitations under the License.
 package client
 
 // DelegatingClient forms an interface Client by composing separate
-// read and write interfaces.  This way, you can have an Client that
+// reader, writer and statusclient interfaces.  This way, you can have an Client that
 // reads from a cache and writes to the API server.
 type DelegatingClient struct {
 	Reader
 	Writer
+	StatusClient
 }

pkg/manager/manager.go

@@ -132,7 +132,6 @@ func New(config *rest.Config, options Options) (Manager, error) {
 	cache, err := options.newCache(config, cache.Options{Scheme: options.Scheme, Mapper: mapper, Resync: options.SyncPeriod})
 	if err != nil {
 		return nil, err
-
 	}
 	// Create the recorder provider to inject event recorders for the components.
 	recorderProvider, err := options.newRecorderProvider(config, options.Scheme)
@@ -146,7 +145,7 @@ func New(config *rest.Config, options Options) (Manager, error) {
 		errChan:          make(chan error),
 		cache:            cache,
 		fieldIndexes:     cache,
-		client:           client.DelegatingClient{Reader: cache, Writer: writeObj},
+		client:           client.DelegatingClient{Reader: cache, Writer: writeObj, StatusClient: writeObj},
 		recorderProvider: recorderProvider,
 	}, nil
 }