layer1: share namespace watcher event handlers

doc/thinking/2026-04-26-namespace-manager-step42.md

@@ -0,0 +1,17 @@
+# 2026-04-26 — NamespaceManager rewrite, step 42
+
+## Цель шага
+
+Убрать последний крупный слой дублирования в namespace watcher-ах: сами `ResourceEventHandlerFuncs`.
+
+## Что меняем
+
+1. В `utils` добавляем `NewNamespaceWatcherEventHandlers()`.
+2. Конструктор собирает общий `Add/Update/Delete` flow на базе уже существующих handler helper-ов.
+3. `buildermgr`, `router`, `executor/multitenant` используют общий конструктор.
+
+## Что НЕ меняем
+
+- не меняем label selector;
+- не меняем manager semantics;
+- не меняем removal policy по умолчанию.

pkg/buildermgr/ns_watcher.go

@@ -45,24 +45,7 @@ func StartNSWatcher(
 
 	nsInformer := factory.Core().V1().Namespaces().Informer()
 
-	_, _ = nsInformer.AddEventHandler(k8sCache.ResourceEventHandlerFuncs{
+	_, _ = nsInformer.AddEventHandler(utils.NewNamespaceWatcherEventHandlers(ctx, logger, "buildermgr.NSWatcher", nsManager, utils.NamespaceRemovalStrategyTrackOnly))
-		AddFunc: func(obj interface{}) {
-			nsObj, ok := obj.(*corev1.Namespace)
-			if ok {
-				utils.HandleWatcherNamespaceAdd(ctx, logger, "buildermgr.NSWatcher", nsManager, nsObj)
-			}
-		},
-		UpdateFunc: func(oldObj, newObj interface{}) {
-			oldNSObj, _ := oldObj.(*corev1.Namespace)
-			nsObj, ok := newObj.(*corev1.Namespace)
-			if ok {
-				utils.HandleWatcherNamespaceUpdate(ctx, logger, "buildermgr.NSWatcher", nsManager, oldNSObj, nsObj, utils.NamespaceRemovalStrategyTrackOnly)
-			}
-		},
-		DeleteFunc: func(obj interface{}) {
-			utils.HandleWatcherNamespaceDelete(ctx, logger, "buildermgr.NSWatcher", nsManager, obj, utils.NamespaceRemovalStrategyTrackOnly)
-		},
-	})
 
 	mgr.Add(ctx, func(ctx context.Context) {
 		logger.Info("buildermgr.NSWatcher: started",

pkg/executor/multitenant/ns_watcher.go

@@ -110,27 +110,7 @@ func StartNSWatcher(
 
 	nsInformer := factory.Core().V1().Namespaces().Informer()
 
-	_, _ = nsInformer.AddEventHandler(k8sCache.ResourceEventHandlerFuncs{
+	_, _ = nsInformer.AddEventHandler(utils.NewNamespaceWatcherEventHandlers(ctx, logger, "multitenant.NSWatcher", nsManager, utils.NamespaceRemovalStrategyTrackOnly))
-		// AddFunc fires when a new Namespace with the label appears.
-		AddFunc: func(obj interface{}) {
-			nsObj, ok := obj.(*corev1.Namespace)
-			if ok {
-				utils.HandleWatcherNamespaceAdd(ctx, logger, "multitenant.NSWatcher", nsManager, nsObj)
-			}
-		},
-		// UpdateFunc fires when an existing Namespace is updated — covers the case
-		// where the label is added to a pre-existing Namespace.
-		UpdateFunc: func(oldObj, newObj interface{}) {
-			oldNSObj, _ := oldObj.(*corev1.Namespace)
-			nsObj, ok := newObj.(*corev1.Namespace)
-			if ok {
-				utils.HandleWatcherNamespaceUpdate(ctx, logger, "multitenant.NSWatcher", nsManager, oldNSObj, nsObj, utils.NamespaceRemovalStrategyTrackOnly)
-			}
-		},
-		DeleteFunc: func(obj interface{}) {
-			utils.HandleWatcherNamespaceDelete(ctx, logger, "multitenant.NSWatcher", nsManager, obj, utils.NamespaceRemovalStrategyTrackOnly)
-		},
-	})
 
 	mgr.Add(ctx, func(ctx context.Context) {
 		logger.Info("multitenant.NSWatcher: started", zap.String("label", utils.ManagedNamespaceLabelSelector()))

pkg/router/ns_watcher.go

@@ -45,24 +45,7 @@ func StartNSWatcher(
 
 	nsInformer := factory.Core().V1().Namespaces().Informer()
 
-	_, _ = nsInformer.AddEventHandler(k8sCache.ResourceEventHandlerFuncs{
+	_, _ = nsInformer.AddEventHandler(utils.NewNamespaceWatcherEventHandlers(ctx, logger, "router.NSWatcher", nsManager, utils.NamespaceRemovalStrategyTrackOnly))
-		AddFunc: func(obj interface{}) {
-			nsObj, ok := obj.(*corev1.Namespace)
-			if ok {
-				utils.HandleWatcherNamespaceAdd(ctx, logger, "router.NSWatcher", nsManager, nsObj)
-			}
-		},
-		UpdateFunc: func(oldObj, newObj interface{}) {
-			oldNSObj, _ := oldObj.(*corev1.Namespace)
-			nsObj, ok := newObj.(*corev1.Namespace)
-			if ok {
-				utils.HandleWatcherNamespaceUpdate(ctx, logger, "router.NSWatcher", nsManager, oldNSObj, nsObj, utils.NamespaceRemovalStrategyTrackOnly)
-			}
-		},
-		DeleteFunc: func(obj interface{}) {
-			utils.HandleWatcherNamespaceDelete(ctx, logger, "router.NSWatcher", nsManager, obj, utils.NamespaceRemovalStrategyTrackOnly)
-		},
-	})
 
 	mgr.Add(ctx, func(ctx context.Context) {
 		logger.Info("router.NSWatcher: started",

pkg/utils/namespace_manager.go

@@ -9,6 +9,7 @@ import (
 
 	"go.uber.org/zap"
 	corev1 "k8s.io/api/core/v1"
+	k8sCache "k8s.io/client-go/tools/cache"
 )
 
 type NamespaceSubscriber interface {
@@ -185,6 +186,27 @@ func HandleWatcherNamespaceRemoval(ctx context.Context, logger *zap.Logger, comp
 		zap.String("namespace", record.Name))
 }
 
+func NewNamespaceWatcherEventHandlers(ctx context.Context, logger *zap.Logger, component string, manager NamespaceManager, strategy NamespaceRemovalStrategy) k8sCache.ResourceEventHandlerFuncs {
+	return k8sCache.ResourceEventHandlerFuncs{
+		AddFunc: func(obj interface{}) {
+			namespace, ok := obj.(*corev1.Namespace)
+			if ok {
+				HandleWatcherNamespaceAdd(ctx, logger, component, manager, namespace)
+			}
+		},
+		UpdateFunc: func(oldObj, newObj interface{}) {
+			oldNamespace, _ := oldObj.(*corev1.Namespace)
+			newNamespace, ok := newObj.(*corev1.Namespace)
+			if ok {
+				HandleWatcherNamespaceUpdate(ctx, logger, component, manager, oldNamespace, newNamespace, strategy)
+			}
+		},
+		DeleteFunc: func(obj interface{}) {
+			HandleWatcherNamespaceDelete(ctx, logger, component, manager, obj, strategy)
+		},
+	}
+}
+
 func (m *inMemoryNamespaceManager) Subscribe(subscriber NamespaceSubscriber) {
 	m.mu.Lock()
 	defer m.mu.Unlock()

pkg/utils/namespace_manager_test.go

@@ -406,6 +406,29 @@ func TestHandleWatcherNamespaceUpdateDispatchRemoval(t *testing.T) {
 	}
 }
 
+func TestNewNamespaceWatcherEventHandlers(t *testing.T) {
+	manager := NewNamespaceManager()
+	router := &testNamespaceSubscriber{name: "router"}
+	manager.Subscribe(router)
+	logger := zap.NewNop()
+	handlers := NewNamespaceWatcherEventHandlers(context.Background(), logger, "router.NSWatcher", manager, NamespaceRemovalStrategyTrackOnly)
+	namespace := &corev1.Namespace{}
+	namespace.Name = "tenant-a"
+	namespace.Labels = map[string]string{ManagedNamespaceLabelKey: ManagedNamespaceLabelValue}
+
+	handlers.AddFunc(namespace)
+	handlers.UpdateFunc(namespace, namespace)
+	handlers.DeleteFunc(k8sCache.DeletedFinalStateUnknown{Obj: namespace})
+
+	record, ok := manager.Get("tenant-a")
+	if !ok || record.Phase != NamespacePhaseRemoved {
+		t.Fatalf("expected watcher event handlers to drive namespace lifecycle")
+	}
+	if router.addCalls != 1 || router.resyncCalls != 1 {
+		t.Fatalf("expected add and resync calls through event handlers")
+	}
+}
+
 func TestNamespaceManagerDispatchAdd(t *testing.T) {
 	manager := NewNamespaceManager()
 	manager.Upsert(NamespaceEvent{Type: NamespaceEventAdd, Name: "tenant-a", Source: NamespaceSourceWatcher})