Configurable MaxConcurrentReconciles

controllers/controllers_suite_test.go

@@ -91,12 +91,13 @@ var _ = BeforeSuite(func() {
 	fakeRecorder = record.NewFakeRecorder(20)
 	// Create a ReconcileNodeMaintenance object with the scheme and fake client
 	r = &NodeMaintenanceReconciler{
-		Client:       k8sClient,
-		Scheme:       scheme.Scheme,
-		MgrConfig:    cfg,
-		LeaseManager: &mockLeaseManager{mockManager},
-		Recorder:     fakeRecorder,
-		logger:       ctrl.Log.WithName("unit test"),
+		Client:                  k8sClient,
+		Scheme:                  scheme.Scheme,
+		MgrConfig:               cfg,
+		LeaseManager:            &mockLeaseManager{mockManager},
+		Recorder:                fakeRecorder,
+		logger:                  ctrl.Log.WithName("unit test"),
+		MaxConcurrentReconciles: 1,
 	}
 	ctx, cancel = context.WithCancel(ctrl.SetupSignalHandler())
 	drainer, err = createDrainer(ctx, cfg)

controllers/nodemaintenance_controller.go

@@ -24,6 +24,7 @@ import (
 	"github.com/go-logr/logr"
 	commonLabels "github.com/medik8s/common/pkg/labels"
 	"github.com/medik8s/common/pkg/lease"
+	"sigs.k8s.io/controller-runtime/pkg/controller"
 
 	corev1 "k8s.io/api/core/v1"
 	apiErrors "k8s.io/apimachinery/pkg/api/errors"
@@ -67,11 +68,16 @@ type NodeMaintenanceReconciler struct {
 	LeaseManager lease.Manager
 	Recorder     record.EventRecorder
 	logger       logr.Logger
+
+	MaxConcurrentReconciles int
 }
 
 // SetupWithManager sets up the controller with the Manager.
 func (r *NodeMaintenanceReconciler) SetupWithManager(mgr ctrl.Manager) error {
 	return ctrl.NewControllerManagedBy(mgr).
+		WithOptions(controller.Options{
+			MaxConcurrentReconciles: r.MaxConcurrentReconciles,
+		}).
 		For(&v1beta1.NodeMaintenance{}).
 		Complete(r)
 }

main.go

@@ -52,7 +52,7 @@ const (
 	WebhookCertDir  = "/apiserver.local.config/certificates"
 	WebhookCertName = "apiserver.crt"
 	WebhookKeyName  = "apiserver.key"
-	operatorName = "NodeMaintenance"
+	operatorName    = "NodeMaintenance"
 )
 
 var (
@@ -69,16 +69,18 @@ func init() {
 
 func main() {
 	var (
-		metricsAddr, probeAddr string
+		metricsAddr, probeAddr            string
 		enableLeaderElection, enableHTTP2 bool
-		webhookOpts          webhook.Options
-	) 
+		webhookOpts                       webhook.Options
+		maxConcurrentReconciles           int
+	)
 	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.BoolVar(&enableHTTP2, "enable-http2", false, "If HTTP/2 should be enabled for the metrics and webhook servers.")
+	flag.IntVar(&maxConcurrentReconciles, "max-concurrent-reconciles", 1, "The number of max concurrent reconciles")
 
 	opts := zap.Options{
 		Development: true,
@@ -94,7 +96,7 @@ func main() {
 	configureWebhookOpts(&webhookOpts, enableHTTP2)
 
 	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
-		Scheme: scheme,
+		Scheme:                 scheme,
 		WebhookServer:          webhook.NewServer(webhookOpts),
 		HealthProbeBindAddress: probeAddr,
 		LeaderElection:         enableLeaderElection,
@@ -105,31 +107,30 @@ func main() {
 		os.Exit(1)
 	}
 
-
 	cl := mgr.GetClient()
 	leaseManagerInitializer := &leaseManagerInitializer{cl: cl}
 	if err := mgr.Add(leaseManagerInitializer); err != nil {
 		setupLog.Error(err, "unable to set up lease Manager", "lease", operatorName)
 		os.Exit(1)
 	}
-	
-	openshiftCheck,err := utils.NewOpenshiftValidator(mgr.GetConfig())
+
+	openshiftCheck, err := utils.NewOpenshiftValidator(mgr.GetConfig())
 	if err != nil {
 		setupLog.Error(err, "failed to check if we run on Openshift")
 		os.Exit(1)
 	}
 	isOpenShift := openshiftCheck.IsOpenshiftSupported()
-	if isOpenShift{
+	if isOpenShift {
 		setupLog.Info("NMO was installed on Openshift cluster")
 	}
-
 
 	if err = (&controllers.NodeMaintenanceReconciler{
-		Client:       cl,
-		Scheme:       mgr.GetScheme(),
-		MgrConfig:    mgr.GetConfig(),
-		LeaseManager: leaseManagerInitializer,
-		Recorder: mgr.GetEventRecorderFor(operatorName),
+		Client:                  cl,
+		Scheme:                  mgr.GetScheme(),
+		MgrConfig:               mgr.GetConfig(),
+		LeaseManager:            leaseManagerInitializer,
+		Recorder:                mgr.GetEventRecorderFor(operatorName),
+		MaxConcurrentReconciles: maxConcurrentReconciles,
 	}).SetupWithManager(mgr); err != nil {
 		setupLog.Error(err, "unable to create controller", "controller", operatorName)
 		os.Exit(1)