Fix sharding flags not being honored

cmd/main.go

@@ -144,8 +144,6 @@ func main() {
 		os.Exit(1)
 	}
 
-	leaderElectionID := fmt.Sprintf("%s-%s", controllerName, "leader-election")
-
 	// Configure the manager with the GitOps Toolkit runtime options.
 	mgrConfig := ctrlruntime.Options{
 		Scheme: scheme,
@@ -155,7 +153,6 @@ func main() {
 		},
 		HealthProbeBindAddress:        healthAddr,
 		LeaderElection:                leaderElectionOptions.Enable,
-		LeaderElectionID:              leaderElectionID,
 		LeaderElectionReleaseOnCancel: leaderElectionOptions.ReleaseOnCancel,
 		LeaseDuration:                 &leaderElectionOptions.LeaseDuration,
 		RenewDeadline:                 &leaderElectionOptions.RenewDeadline,
@@ -174,6 +171,11 @@ func main() {
 		},
 	}
 
+	if err := applyWatchOptions(&mgrConfig, controllerName, watchOptions); err != nil {
+		setupLog.Error(err, "unable to configure watch label selector for manager")
+		os.Exit(1)
+	}
+
 	// Limit the watch scope to the runtime namespace if specified.
 	if !watchOptions.AllNamespaces {
 		mgrConfig.Cache.DefaultNamespaces = map[string]ctrlcache.Config{
@@ -246,6 +248,27 @@ func main() {
 	}
 }
 
+// applyWatchOptions configures the manager cache and leader election for watch selectors.
+func applyWatchOptions(mgrConfig *ctrlruntime.Options, controllerName string, watchOptions gotkctrl.WatchOptions) error {
+	watchSelector, err := gotkctrl.GetWatchSelector(watchOptions)
+	if err != nil {
+		return err
+	}
+
+	leaderElectionID := fmt.Sprintf("%s-%s", controllerName, "leader-election")
+	if watchOptions.LabelSelector != "" {
+		leaderElectionID = gotkelection.GenerateID(leaderElectionID, watchOptions.LabelSelector)
+	}
+	mgrConfig.LeaderElectionID = leaderElectionID
+
+	if mgrConfig.Cache.ByObject == nil {
+		mgrConfig.Cache.ByObject = make(map[ctrlclient.Object]ctrlcache.ByObject)
+	}
+	mgrConfig.Cache.ByObject[&swapi.ArtifactGenerator{}] = ctrlcache.ByObject{Label: watchSelector}
+
+	return nil
+}
+
 func mustSetupEventRecorder(mgr ctrlruntime.Manager, eventsAddr, controllerName string) record.EventRecorder {
 	eventRecorder, err := gotkevents.NewRecorder(mgr, ctrlruntime.Log, eventsAddr, controllerName)
 	if err != nil {

docs/README.md

@@ -41,6 +41,7 @@ with advanced source composition and decomposition patterns.
 | `--storage-adv-addr`                  | string        | The advertised address of the static file server.                                                                                                                                        |
 | `--storage-path`                      | string        | The local storage path. (default "/data")                                                                                                                                                |
 | `--watch-all-namespaces`              | boolean       | Watch for resources in all namespaces, if set to false it will only watch the runtime namespace. (default true)                                                                          |
+| `--watch-label-selector`              | string        | Watch for resources with matching labels e.g. 'sharding.fluxcd.io/shard=shard1'.                                                                                                        |
 | `--feature-gates`                     | mapStringBool | A comma separated list of key=value pairs defining the state of experimental features.                                                                                                   |
 
 ### Feature Gates