From 93845c01d95eedb00959832f37b093f874018768 Mon Sep 17 00:00:00 2001
From: Stefan Catargiu <stefan.catargiu@gmx.de>
Date: Wed, 7 Feb 2024 18:02:12 +0100
Subject: [PATCH] Only reconcile ip objects with specific label

---
 controllers/controllers_test.go |  2 +-
 controllers/ip_controller.go    | 35 ++++++++++++++++++++++++++-------
 main.go                         |  8 +++++++-
 3 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/controllers/controllers_test.go b/controllers/controllers_test.go
index 5bf902c..ed96a50 100644
--- a/controllers/controllers_test.go
+++ b/controllers/controllers_test.go
@@ -84,7 +84,7 @@ var _ = BeforeSuite(func() {
 	Expect(err).NotTo(HaveOccurred())
 	Expect(mgr).NotTo(BeNil())
 
-	ipReconciler, err = NewIPReconciler("")
+	ipReconciler, err = NewIPReconciler("", "", "")
 	Expect(err).NotTo(HaveOccurred())
 	Expect(ipReconciler.SetupWithManager(mgr)).To(Succeed())
 
diff --git a/controllers/ip_controller.go b/controllers/ip_controller.go
index 7de97a0..1851127 100644
--- a/controllers/ip_controller.go
+++ b/controllers/ip_controller.go
@@ -39,19 +39,23 @@ import (
 //+kubebuilder:rbac:groups=ipam.onmetal.de,resources=ips,verbs=get;list;watch
 //+kubebuilder:rbac:groups=ipam.onmetal.de,resources=ips/status,verbs=get
 
-func NewIPReconciler(namespace string) (*IPReconciler, error) {
+func NewIPReconciler(namespace string, subnetLabelName string, subnetLabelValue string) (*IPReconciler, error) {
 	return &IPReconciler{
-		namespace: namespace,
+		namespace:        namespace,
+		subnetLabelName:  subnetLabelName,
+		subnetLabelValue: subnetLabelValue,
 	}, nil
 }
 
 // IPReconciler reconciles a IP object.
 type IPReconciler struct {
 	client.Client
-	namespace   string
-	disabled    bool
-	disabledMtx sync.RWMutex
-	macRegex    *regexp.Regexp
+	namespace        string
+	subnetLabelName  string
+	subnetLabelValue string
+	disabled         bool
+	disabledMtx      sync.RWMutex
+	macRegex         *regexp.Regexp
 }
 
 func (r *IPReconciler) enable() {
@@ -268,5 +272,22 @@ func (r *IPReconciler) SetupWithManager(mgr ctrl.Manager) error {
 		},
 	}
 
-	return ctrl.NewControllerManagedBy(mgr).For(&ipamv1alpha1.IP{}).WithEventFilter(predicate.And(predicate.GenerationChangedPredicate{}, inCorrectNamespacePredicate, notBeingDeletedPredicate, validPredicate)).WithOptions(controller.Options{MaxConcurrentReconciles: 10}).Complete(r)
+	hasValidLabelPredicate := predicate.Funcs{
+		CreateFunc: func(e event.CreateEvent) bool {
+			if r.subnetLabelName != "" {
+				l, ok := e.Object.GetLabels()[r.subnetLabelName]
+				return ok && l == r.subnetLabelValue
+			}
+			return true
+		},
+		UpdateFunc: func(e event.UpdateEvent) bool {
+			if r.subnetLabelName != "" {
+				l, ok := e.ObjectNew.GetLabels()[r.subnetLabelName]
+				return ok && l == r.subnetLabelValue
+			}
+			return true
+		},
+	}
+
+	return ctrl.NewControllerManagedBy(mgr).For(&ipamv1alpha1.IP{}).WithEventFilter(predicate.And(predicate.GenerationChangedPredicate{}, inCorrectNamespacePredicate, notBeingDeletedPredicate, validPredicate, hasValidLabelPredicate)).WithOptions(controller.Options{MaxConcurrentReconciles: 10}).Complete(r)
 }
diff --git a/main.go b/main.go
index f2dbeb1..6e3ea1f 100644
--- a/main.go
+++ b/main.go
@@ -73,6 +73,8 @@ type params struct {
 	shutdownTimeout        time.Duration
 	consoleServerCert      string
 	consoleServerKey       string
+	subnetLabelName        string
+	subnetLabelValue       string
 }
 
 func parseCmdLine() params {
@@ -91,6 +93,8 @@ func parseCmdLine() params {
 	pflag.Duration("shutdown-timeout", 5*time.Minute, "Wait this long before issuing an immediate shutdown, if graceful shutdown has not succeeded. See https://golang.org/pkg/time/#ParseDuration")
 	pflag.String("console-server-cert", "", "Use a TLS certificate for the console server. If not set, do not start the console server.")
 	pflag.String("console-server-key", "", "Use a TLS key for the console server. If not set, do not start the console server.")
+	pflag.String("subnet-label-name", "", "Label name used to filter ip.ipam objects. Not specifying it will reconcile ALL ip.ipam objects.")
+	pflag.String("subnet-label-value", "", "Label value used to filter ip.ipam objects.")
 
 	var help bool
 	pflag.BoolVarP(&help, "help", "h", false, "Show this help message.")
@@ -120,6 +124,8 @@ func parseCmdLine() params {
 		shutdownTimeout:        viper.GetDuration("shutdown-timeout"),
 		consoleServerCert:      viper.GetString("console-server-cert"),
 		consoleServerKey:       viper.GetString("console-server-key"),
+		subnetLabelName:        viper.GetString("subnet-label-name"),
+		subnetLabelValue:       viper.GetString("subnet-label-value"),
 	}
 }
 
@@ -205,7 +211,7 @@ func main() {
 	}
 
 	var ipReconciler *controllers.IPReconciler
-	ipReconciler, err = controllers.NewIPReconciler(p.namespace)
+	ipReconciler, err = controllers.NewIPReconciler(p.namespace, p.subnetLabelName, p.subnetLabelValue)
 	if err != nil {
 		log.Error(ctx, fmt.Errorf("cannot create controller: %w", err), "controller", "IP")
 		exitCode = 1