Fix bug of deleting entities that were stale after reupserting

pkg/handlers/controllers.go

@@ -54,14 +54,18 @@ func NewControllersHandler(exporterConfig *config.Config, k8sClient *k8s.Client,
 func (c *ControllersHandler) Handle(stopCh <-chan struct{}) {
 	klog.Info("Starting informers")
 	c.informersFactory.Start(stopCh)
-	klog.Info("Starting controllers")
+	klog.Info("Waiting for informers cache sync")
 	for _, controller := range c.controllers {
-		if err := controller.Run(1, stopCh); err != nil {
-			klog.Fatalf("Error running controller: %s", err.Error())
+		if err := controller.WaitForCacheSync(stopCh); err != nil {
+			klog.Fatalf("Error while waiting for informer cache sync: %s", err.Error())
 		}
 	}
 	klog.Info("Deleting stale entities")
-	go c.RunDeleteStaleEntities()
+	c.RunDeleteStaleEntities()
+	klog.Info("Starting controllers")
+	for _, controller := range c.controllers {
+		controller.Run(1, stopCh)
+	}
 
 	<-stopCh
 	klog.Info("Shutting down controllers")

pkg/k8s/controller.go

@@ -94,21 +94,23 @@ func (c *Controller) Shutdown() {
 	klog.Infof("Closed controller for resource '%s'", c.resource.Kind)
 }
 
-func (c *Controller) Run(workers int, stopCh <-chan struct{}) error {
-	defer utilruntime.HandleCrash()
-
+func (c *Controller) WaitForCacheSync(stopCh <-chan struct{}) error {
 	klog.Infof("Waiting for informer cache to sync for resource '%s'", c.resource.Kind)
 	if ok := cache.WaitForCacheSync(stopCh, c.informer.HasSynced); !ok {
 		return fmt.Errorf("failed to wait for caches to sync")
 	}
 
+	return nil
+}
+
+func (c *Controller) Run(workers int, stopCh <-chan struct{}) {
+	defer utilruntime.HandleCrash()
+
 	klog.Infof("Starting workers for resource '%s'", c.resource.Kind)
 	for i := 0; i < workers; i++ {
 		go wait.Until(c.runWorker, time.Second, stopCh)
 	}
 	klog.Infof("Started workers for resource '%s'", c.resource.Kind)
-
-	return nil
 }
 
 func (c *Controller) runWorker() {