Merge pull request kubernetes#83965 from robscott/endpointslice-managed-by

Adding new label to indicate what is managing an EndpointSlice

Author: k8s-ci-robot

pkg/controller/endpointslice/endpointslice_controller.go

@@ -54,6 +54,20 @@ const (
 	// 5ms, 10ms, 20ms, 40ms, 80ms, 160ms, 320ms, 640ms, 1.3s, 2.6s, 5.1s,
 	// 10.2s, 20.4s, 41s, 82s
 	maxRetries = 15
+	// controllerName is a unique value used with LabelManagedBy to indicated
+	// the component managing an EndpointSlice.
+	controllerName = "endpointslice-controller.k8s.io"
+	// managedBySetupAnnotation is set on a Service to indicate that
+	// EndpointSlices for the Service have already been configured with
+	// LabelManagedBy. If this annotation is not set, all related EndpointSlices
+	// will have LabelManagedBy set to reference this controller if the label
+	// is not already set. Once all EndpointSlices are labeled, the Controller
+	// will set this annotation on the Service.
+	managedBySetupAnnotation = "endpointslice.kubernetes.io/managed-by-setup"
+	// managedBySetupCompleteValue represents the value of the
+	// managedBySetupAnnotation that indicates that the setup process has been
+	// completed for a Service.
+	managedBySetupCompleteValue = "true"
 )
 
 // NewController creates and initializes a new Controller
@@ -286,7 +300,28 @@ func (c *Controller) syncService(key string) error {
 		return err
 	}
 
-	esLabelSelector := labels.Set(map[string]string{discovery.LabelServiceName: service.Name}).AsSelectorPreValidated()
+	// With the goal of different controllers being able to manage different
+	// subsets of EndpointSlices, LabelManagedBy has been added to indicate
+	// which controller or entity manages an EndpointSlice. As part of this
+	// v1.16->v1.17 change, EndpointSlices will initially be assumed to be
+	// managed by this controller unless a label is set to indicate otherwise.
+	// To ensure a seamless upgrade process, the managedBySetupAnnotation is
+	// used to indicate that LabelManagedBy has been set initially for related
+	// EndpointSlices. If it hasn't been set to the expected value here, we call
+	// ensureSetupManagedByAnnotation() to set up LabelManagedBy on each
+	// EndpointSlice.
+	// TODO(robscott): Remove this before v1.18.
+	err = c.ensureSetupManagedByAnnotation(service)
+	if err != nil {
+		c.eventRecorder.Eventf(service, v1.EventTypeWarning, "FailedToSetEndpointSliceManagedByLabel",
+			"Error adding managed-by Label to Endpoint Slices for Service %s/%s: %v", service.Namespace, service.Name, err)
+		return err
+	}
+
+	esLabelSelector := labels.Set(map[string]string{
+		discovery.LabelServiceName: service.Name,
+		discovery.LabelManagedBy:   controllerName,
+	}).AsSelectorPreValidated()
 	endpointSlices, err := c.endpointSliceLister.EndpointSlices(service.Namespace).List(esLabelSelector)
 
 	if err != nil {
@@ -337,6 +372,49 @@ func (c *Controller) onServiceDelete(obj interface{}) {
 	c.queue.Add(key)
 }
 
+// ensureSetupManagedByAnnotation selects all EndpointSlices for a Service and
+// ensures they have LabelManagedBy set appropriately. This ensures that only
+// one controller or entity is trying to manage a given EndpointSlice. This
+// function provides backwards compatibility with the initial alpha release of
+// EndpointSlices that did not include these labels.
+// TODO(robscott): Remove this in time for v1.18.
+func (c *Controller) ensureSetupManagedByAnnotation(service *v1.Service) error {
+	if managedBySetup, ok := service.Annotations[managedBySetupAnnotation]; ok && managedBySetup == managedBySetupCompleteValue {
+		return nil
+	}
+
+	esLabelSelector := labels.Set(map[string]string{discovery.LabelServiceName: service.Name}).AsSelectorPreValidated()
+	endpointSlices, err := c.endpointSliceLister.EndpointSlices(service.Namespace).List(esLabelSelector)
+
+	if err != nil {
+		c.eventRecorder.Eventf(service, v1.EventTypeWarning, "FailedToListEndpointSlices",
+			"Error listing Endpoint Slices for Service %s/%s: %v", service.Namespace, service.Name, err)
+		return err
+	}
+
+	for _, endpointSlice := range endpointSlices {
+		if _, ok := endpointSlice.Labels[discovery.LabelManagedBy]; !ok {
+			if endpointSlice.Labels == nil {
+				endpointSlice.Labels = make(map[string]string)
+			}
+
+			endpointSlice.Labels[discovery.LabelManagedBy] = controllerName
+			_, err = c.client.DiscoveryV1alpha1().EndpointSlices(endpointSlice.Namespace).Update(endpointSlice)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	if service.Annotations == nil {
+		service.Annotations = make(map[string]string)
+	}
+
+	service.Annotations[managedBySetupAnnotation] = managedBySetupCompleteValue
+	_, err = c.client.CoreV1().Services(service.Namespace).Update(service)
+	return err
+}
+
 func (c *Controller) addPod(obj interface{}) {
 	pod := obj.(*v1.Pod)
 	services, err := c.serviceSelectorCache.GetPodServiceMemberships(c.serviceLister, pod)