fix: Don't try watching items without resourceVersion

Trying to watch items without resourceVersion will fail.
Instead of failing and retrying every second, wait until
the next resync interval and try again then.

This reduces load and log spam.

Signed-off-by: Daniel Vassdal <daniel@vassdal.org>

Author: ShutterQuick

pkg/cache/cluster.go

@@ -666,6 +666,29 @@ func (c *clusterCache) watchEvents(ctx context.Context, api kube.APIResourceInfo
 			}
 		}
 
+		// If the resourceVersion is still missing, watchutil.NewRetryWatcher will fail.
+		// https://github.com/kubernetes/client-go/blob/78d2af792babf2dd937ba2e2a8d99c753a5eda89/tools/watch/retrywatcher.go#L68-L71
+		// Instead, let's just check if the resourceVersion exists at the next resync ...
+		if resourceVersion == "" {
+			c.log.V(1).Info(fmt.Sprintf("Ignoring watch for %s on %s due to missing resourceVersion", api.GroupKind, c.config.Host))
+
+			var watchResyncTimeoutCh <-chan time.Time
+			if c.watchResyncTimeout > 0 {
+				shouldResync := time.NewTimer(c.watchResyncTimeout)
+				defer shouldResync.Stop()
+				watchResyncTimeoutCh = shouldResync.C
+			}
+
+			for {
+				select {
+				case <-ctx.Done():
+					return nil
+				case <-watchResyncTimeoutCh:
+					return fmt.Errorf("Resyncing %s on %s due to timeout", api.GroupKind, c.config.Host)
+				}
+			}
+		}
+
 		w, err := watchutil.NewRetryWatcher(resourceVersion, &cache.ListWatch{
 			WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
 				res, err := resClient.Watch(ctx, options)