Add watch-filter support to kubeadm controlplane controller

Author: Tuomas Mäkinen

bootstrap/kubeadm/controllers/kubeadmconfig_controller.go

@@ -121,7 +121,7 @@ func (r *KubeadmConfigReconciler) SetupWithManager(ctx context.Context, mgr ctrl
 		handler.EnqueueRequestsFromMapFunc(r.ClusterToKubeadmConfigs),
 		predicates.All(ctrl.LoggerFrom(ctx),
 			predicates.ClusterUnpausedAndInfrastructureReady(ctrl.LoggerFrom(ctx)),
-			predicates.ResourceNotPausedAndHasFilterLabel(ctrl.LoggerFrom(ctx), r.WatchFilterValue),
+			predicates.ResourceHasFilterLabel(ctrl.LoggerFrom(ctx), r.WatchFilterValue),
 		),
 	)
 	if err != nil {

controlplane/kubeadm/controllers/controller.go

@@ -59,10 +59,11 @@ import (
 
 // KubeadmControlPlaneReconciler reconciles a KubeadmControlPlane object.
 type KubeadmControlPlaneReconciler struct {
-	Client     client.Client
-	controller controller.Controller
-	recorder   record.EventRecorder
-	Tracker    *remote.ClusterCacheTracker
+	Client           client.Client
+	controller       controller.Controller
+	recorder         record.EventRecorder
+	Tracker          *remote.ClusterCacheTracker
+	WatchFilterValue string
 
 	managementCluster         internal.ManagementCluster
 	managementClusterUncached internal.ManagementCluster
@@ -73,7 +74,7 @@ func (r *KubeadmControlPlaneReconciler) SetupWithManager(ctx context.Context, mg
 		For(&controlplanev1.KubeadmControlPlane{}).
 		Owns(&clusterv1.Machine{}).
 		WithOptions(options).
-		WithEventFilter(predicates.ResourceNotPaused(ctrl.LoggerFrom(ctx))).
+		WithEventFilter(predicates.ResourceNotPausedAndHasFilterLabel(ctrl.LoggerFrom(ctx), r.WatchFilterValue)).
 		Build(r)
 	if err != nil {
 		return errors.Wrap(err, "failed setting up with a controller manager")
@@ -82,7 +83,10 @@ func (r *KubeadmControlPlaneReconciler) SetupWithManager(ctx context.Context, mg
 	err = c.Watch(
 		&source.Kind{Type: &clusterv1.Cluster{}},
 		handler.EnqueueRequestsFromMapFunc(r.ClusterToKubeadmControlPlane),
-		predicates.ClusterUnpausedAndInfrastructureReady(ctrl.LoggerFrom(ctx)),
+		predicates.All(ctrl.LoggerFrom(ctx),
+			predicates.ResourceHasFilterLabel(ctrl.LoggerFrom(ctx), r.WatchFilterValue),
+			predicates.ClusterUnpausedAndInfrastructureReady(ctrl.LoggerFrom(ctx)),
+		),
 	)
 	if err != nil {
 		return errors.Wrap(err, "failed adding Watch for Clusters to controller manager")

controlplane/kubeadm/main.go

@@ -19,6 +19,7 @@ package main
 import (
 	"context"
 	"flag"
+	"fmt"
 	"math/rand"
 	"net/http"
 	_ "net/http/pprof"
@@ -68,6 +69,7 @@ var (
 	leaderElectionLeaseDuration    time.Duration
 	leaderElectionRenewDeadline    time.Duration
 	leaderElectionRetryPeriod      time.Duration
+	watchFilterValue               string
 	watchNamespace                 string
 	profilerAddress                string
 	kubeadmControlPlaneConcurrency int
@@ -106,6 +108,9 @@ func InitFlags(fs *pflag.FlagSet) {
 	fs.DurationVar(&syncPeriod, "sync-period", 10*time.Minute,
 		"The minimum interval at which watched resources are reconciled (e.g. 15m)")
 
+	fs.StringVar(&watchFilterValue, "watch-filter", "",
+		fmt.Sprintf("Label value that the controller watches to reconcile cluster-api objects. Label key is always %s. If unspecified, the controller watches for all cluster-api objects.", clusterv1.WatchLabel))
+
 	fs.IntVar(&webhookPort, "webhook-port", 9443,
 		"Webhook Server port")
 
@@ -193,17 +198,19 @@ func setupReconcilers(ctx context.Context, mgr ctrl.Manager) {
 		os.Exit(1)
 	}
 	if err := (&remote.ClusterCacheReconciler{
-		Client:  mgr.GetClient(),
-		Log:     ctrl.Log.WithName("remote").WithName("ClusterCacheReconciler"),
-		Tracker: tracker,
+		Client:           mgr.GetClient(),
+		Log:              ctrl.Log.WithName("remote").WithName("ClusterCacheReconciler"),
+		Tracker:          tracker,
+		WatchFilterValue: watchFilterValue,
 	}).SetupWithManager(ctx, mgr, concurrency(kubeadmControlPlaneConcurrency)); err != nil {
 		setupLog.Error(err, "unable to create controller", "controller", "ClusterCacheReconciler")
 		os.Exit(1)
 	}
 
 	if err := (&kubeadmcontrolplanecontrollers.KubeadmControlPlaneReconciler{
-		Client:  mgr.GetClient(),
-		Tracker: tracker,
+		Client:           mgr.GetClient(),
+		Tracker:          tracker,
+		WatchFilterValue: watchFilterValue,
 	}).SetupWithManager(ctx, mgr, concurrency(kubeadmControlPlaneConcurrency)); err != nil {
 		setupLog.Error(err, "unable to create controller", "controller", "KubeadmControlPlane")
 		os.Exit(1)