Support watchNamespace for controller

Author: jayesh-srivastava

main.go

@@ -70,17 +70,23 @@ func main() {
 	var metricsAddr string
 	var enableLeaderElection bool
 	var probeAddr string
+	var watchNamespace string
 	flag.StringVar(&metricsAddr, "metrics-bind-address", ":8080", "The address the metric endpoint binds to.")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. "+
 			"Enabling this will ensure there is only one active controller manager.")
+	flag.StringVar(&watchNamespace, "namespace", "", "Namespace that the controller watches to reconcile cluster-api objects. If unspecified, the controller watches for cluster-api objects across all namespaces.")
 	opts := zap.Options{
 		Development: true,
 	}
 	opts.BindFlags(flag.CommandLine)
 	flag.Parse()
 
+	if watchNamespace != "" {
+		setupLog.Info("Watching cluster-api objects only in namespace for reconciliation", "namespace", watchNamespace)
+	}
+
 	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))
 	restConfig := ctrl.GetConfigOrDie()
 	restConfig.UserAgent = remote.DefaultClusterAPIUserAgent("cluster-api-microk8s-bootstrap-manager")
@@ -94,6 +100,7 @@ func main() {
 			&corev1.ConfigMap{},
 			&corev1.Secret{},
 		},
+		Namespace: watchNamespace,
 	})
 	if err != nil {
 		setupLog.Error(err, "unable to start manager")