Merge pull request #174 from hasbro17/haseeb/return-delete-events

informer: save deleted object and pass delete event to handler

Author: hasbro17

example/memcached-operator/handler.go.tmpl

@@ -29,6 +29,12 @@ func (h *Handler) Handle(ctx types.Context, event types.Event) error {
 	case *v1alpha1.Memcached:
 		memcached := o
 
+		// Ignore the delete event since the garbage collector will clean up all secondary resources for the CR
+		// All secondary resources must have the CR set as their OwnerReference for this to be the case
+		if event.Deleted {
+			return nil
+		}
+
 		// Create the deployment if it doesn't exist
 		dep := deploymentForMemcached(memcached)
 		err := action.Create(dep)

pkg/sdk/informer/informer.go

@@ -39,13 +39,15 @@ type informer struct {
 	queue               workqueue.RateLimitingInterface
 	namespace           string
 	context             context.Context
+	deletedObjects      map[string]interface{}
 }
 
 func New(resourcePluralName, namespace string, resourceClient dynamic.ResourceInterface, resyncPeriod int) Informer {
 	i := &informer{
 		resourcePluralName: resourcePluralName,
 		queue:              workqueue.NewNamedRateLimitingQueue(workqueue.DefaultControllerRateLimiter(), resourcePluralName),
 		namespace:          namespace,
+		deletedObjects:     map[string]interface{}{},
 	}
 
 	resyncDuration := time.Duration(resyncPeriod) * time.Second
@@ -104,6 +106,11 @@ func (i *informer) handleDeleteResourceEvent(obj interface{}) {
 	if err != nil {
 		panic(err)
 	}
+
+	// TODO: Revisit the need for passing delete events to the handler
+	// Save the last known state for the deleted object
+	i.deletedObjects[key] = obj.(*unstructured.Unstructured).DeepCopy()
+
 	i.queue.Add(key)
 }
 

pkg/sdk/informer/sync.go

@@ -57,15 +57,21 @@ func (i *informer) processNextItem() bool {
 	return true
 }
 
-// sync creates the event for the object, sends it to the handler, and processes the resulting actions
+// sync creates the event for the object and sends it to the handler
 func (i *informer) sync(key string) error {
 	obj, exists, err := i.sharedIndexInformer.GetIndexer().GetByKey(key)
 	if err != nil {
 		return err
 	}
 	if !exists {
 		logrus.Infof("Object (%s) is deleted", key)
-		return nil
+		// Lookup the last saved state for the deleted object
+		_, ok := i.deletedObjects[key]
+		if !ok {
+			logrus.Errorf("No last known state found for deleted object (%s)", key)
+			return nil
+		}
+		obj = i.deletedObjects[key]
 	}
 
 	unstructObj := obj.(*unstructured.Unstructured).DeepCopy()
@@ -78,7 +84,11 @@ func (i *informer) sync(key string) error {
 
 	sdkCtx := sdkTypes.Context{Context: i.context}
 	// TODO: Add option to prevent multiple informers from invoking Handle() concurrently?
-	return sdkHandler.RegisteredHandler.Handle(sdkCtx, event)
+	err = sdkHandler.RegisteredHandler.Handle(sdkCtx, event)
+	if !exists && err == nil {
+		delete(i.deletedObjects, key)
+	}
+	return err
 }
 
 // handleErr checks if an error happened and makes sure we will retry later.