Use wait.ExponentialBackoff instead of a fixed interval polling

cmd/snapshot-controller/main.go

@@ -63,34 +63,36 @@ var (
 	version = "unknown"
 )
 
-// Checks that the VolumeSnapshot v1 CRDs.
+// Checks that the VolumeSnapshot v1 CRDs exist.
 func ensureCustomResourceDefinitionsExist(client *clientset.Clientset) error {
-	timeoutCh := make(chan struct{})
-	go func() {
-		defer close(timeoutCh)
-		time.Sleep(10 * time.Second)
-	}()
-
 	condition := func() (bool, error) {
 		var err error
 		_, err = client.SnapshotV1().VolumeSnapshots("kube-system").List(context.TODO(), metav1.ListOptions{})
 		if err != nil {
-			return false, err
+			klog.Errorf("Failed to list v1 volumesnapshots with error=%+v", err)
+			return false, nil
 		}
 		_, err = client.SnapshotV1().VolumeSnapshotClasses().List(context.TODO(), metav1.ListOptions{})
 		if err != nil {
-			return false, err
+			klog.Errorf("Failed to list v1 volumesnapshotclasses with error=%+v", err)
+			return false, nil
 		}
 		_, err = client.SnapshotV1().VolumeSnapshotContents().List(context.TODO(), metav1.ListOptions{})
 		if err != nil {
-			return false, err
+			klog.Errorf("Failed to list v1 volumesnapshotcontents with error=%+v", err)
+			return false, nil
 		}
 		return true, nil
 	}
 
-	pollPeriod := 100 * time.Millisecond
-	if err := wait.PollImmediateUntil(pollPeriod, condition, timeoutCh); err != nil {
-		return fmt.Errorf("Failed to fetch VolumeSnapshot CRDs: %+v", err)
+	// with a Factor of 1.5 we wait up to 7.5 seconds (the 10th attempt)
+	backoff := wait.Backoff{
+		Duration: 100 * time.Millisecond,
+		Factor:   1.5,
+		Steps:    10,
+	}
+	if err := wait.ExponentialBackoff(backoff, condition); err != nil {
+		return err
 	}
 	return nil
 }