discard cluster events from the queue on cluster delete;

delete cluster from the clusters map before deleting cluster itself

pkg/controller/postgresql.go

@@ -193,26 +193,20 @@ func (c *Controller) processEvent(event spec.ClusterEvent) {
 		cl.Error = nil
 		lg.Infoln("cluster has been updated")
 	case spec.EventDelete:
-		teamName := strings.ToLower(cl.Spec.TeamID)
-
-		lg.Infoln("Deletion of the cluster started")
 		if !clusterFound {
 			lg.Errorf("unknown cluster: %q", clusterName)
 			return
 		}
+		lg.Infoln("deletion of the cluster started")
 
-		if err := cl.Delete(); err != nil {
-			lg.Errorf("could not delete cluster: %v", err)
-			return
-		}
-
+		teamName := strings.ToLower(cl.Spec.TeamID)
 		func() {
 			defer c.clustersMu.Unlock()
 			c.clustersMu.Lock()
 
 			delete(c.clusters, clusterName)
 			delete(c.clusterLogs, clusterName)
-			for i, val := range c.teamClusters[teamName] { // on relativel
+			for i, val := range c.teamClusters[teamName] {
 				if val == clusterName {
 					copy(c.teamClusters[teamName][i:], c.teamClusters[teamName][i+1:])
 					c.teamClusters[teamName][len(c.teamClusters[teamName])-1] = spec.NamespacedName{}
@@ -222,6 +216,11 @@ func (c *Controller) processEvent(event spec.ClusterEvent) {
 			}
 		}()
 
+		if err := cl.Delete(); err != nil {
+			lg.Errorf("could not delete cluster: %v", err)
+			return
+		}
+
 		lg.Infof("cluster has been deleted")
 	case spec.EventSync:
 		lg.Infof("syncing of the cluster started")
@@ -305,13 +304,35 @@ func (c *Controller) queueClusterEvent(old, new *spec.Postgresql, eventType spec
 		NewSpec:   new,
 		WorkerID:  workerID,
 	}
-	//TODO: if we delete cluster, discard all the previous events for the cluster
 
 	lg := c.logger.WithField("worker", workerID).WithField("cluster-name", clusterName)
 	if err := c.clusterEventQueues[workerID].Add(clusterEvent); err != nil {
-		lg.Errorf("error when queueing cluster event: %v", clusterEvent)
+		lg.Errorf("error while queueing cluster event: %v", clusterEvent)
 	}
 	lg.Infof("%q event has been queued", eventType)
+
+	if eventType != spec.EventDelete {
+		return
+	}
+
+	for _, evType := range []spec.EventType{spec.EventAdd, spec.EventSync, spec.EventUpdate} {
+		obj, exists, err := c.clusterEventQueues[workerID].GetByKey(queueClusterKey(evType, uid))
+		if err != nil {
+			lg.Warningf("could not get event from the queue: %v", err)
+			continue
+		}
+
+		if !exists {
+			continue
+		}
+
+		err = c.clusterEventQueues[workerID].Delete(obj)
+		if err != nil {
+			lg.Warningf("could not delete event from the queue: %v", err)
+		} else {
+			lg.Debugf("event %q has been discarded for the cluster", evType)
+		}
+	}
 }
 
 func (c *Controller) postgresqlAdd(obj interface{}) {