feat(federate): add backoff for reenqueue on unsynced cache

pkg/controllers/federate/controller.go

@@ -31,6 +31,7 @@ import (
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/tools/cache"
 	"k8s.io/client-go/tools/record"
+	"k8s.io/client-go/util/workqueue"
 	"k8s.io/klog/v2"
 	"k8s.io/utils/pointer"
 
@@ -74,8 +75,9 @@ type FederateController struct {
 	fedClient     fedclient.Interface
 	dynamicClient dynamic.Interface
 
-	worker        worker.ReconcileWorker[workerKey]
-	eventRecorder record.EventRecorder
+	worker               worker.ReconcileWorker[workerKey]
+	cacheSyncRateLimiter workqueue.RateLimiter
+	eventRecorder        record.EventRecorder
 
 	metrics stats.Metrics
 	logger  klog.Logger
@@ -103,6 +105,7 @@ func NewFederateController(
 		clusterFedObjectInformer: clusterFedObjectInformer,
 		fedClient:                fedClient,
 		dynamicClient:            dynamicClient,
+		cacheSyncRateLimiter:     workqueue.NewItemExponentialFailureRateLimiter(100*time.Millisecond, 10*time.Second),
 		metrics:                  metrics,
 		logger:                   logger.WithValues("controller", FederateControllerName),
 	}
@@ -267,9 +270,10 @@ func (c *FederateController) reconcile(ctx context.Context, key workerKey) (stat
 		logger.V(3).Info("Lister for source type not yet synced, will reenqueue")
 		return worker.Result{
 			Success:      true,
-			RequeueAfter: pointer.Duration(100 * time.Millisecond),
+			RequeueAfter: pointer.Duration(c.cacheSyncRateLimiter.When(key)),
 		}
 	}
+	c.cacheSyncRateLimiter.Forget(key)
 
 	sourceUns, err := lister.Get(key.QualifiedName().String())
 	if err != nil && apierrors.IsNotFound(err) {