layer1: share managed namespace watcher startup

doc/thinking/2026-04-26-namespace-manager-step43.md

@@ -0,0 +1,19 @@
+# 2026-04-26 — NamespaceManager rewrite, step 43
+
+## Цель шага
+
+Убрать оставшуюся копипасту старта namespace informer-а из `buildermgr`, `router`, `executor/multitenant`.
+
+## Что меняем
+
+1. В `utils` добавляем `StartManagedNamespaceWatcher()`.
+2. Helper централизует:
+   - informer factory с label selector;
+   - регистрацию event handlers;
+   - start/cache sync/stop logging через `mgr`.
+3. Три watcher-а переходят на общий helper.
+
+## Что НЕ меняем
+
+- не меняем lifecycle logic;
+- не меняем selector contract `fission.io/managed=true`.

pkg/buildermgr/ns_watcher.go

@@ -10,11 +10,7 @@ import (
 	"time"
 
 	"go.uber.org/zap"
-	corev1 "k8s.io/api/core/v1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	k8sInformers "k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes"
-	k8sCache "k8s.io/client-go/tools/cache"
 
 	"github.com/fission/fission/pkg/utils"
 	"github.com/fission/fission/pkg/utils/manager"
@@ -34,26 +30,5 @@ func StartNSWatcher(
 	if err != nil {
 		logger.Error("buildermgr.NSWatcher: BootstrapAndDispatch failed", zap.Error(err))
 	}
-
-	factory := k8sInformers.NewSharedInformerFactoryWithOptions(
-		kubeClient,
-		30*time.Minute,
-		k8sInformers.WithTweakListOptions(func(opts *metav1.ListOptions) {
-			opts.LabelSelector = utils.ManagedNamespaceLabelSelector()
-		}),
-	)
-
-	nsInformer := factory.Core().V1().Namespaces().Informer()
-
-	_, _ = nsInformer.AddEventHandler(utils.NewNamespaceWatcherEventHandlers(ctx, logger, "buildermgr.NSWatcher", nsManager, utils.NamespaceRemovalStrategyTrackOnly))
-
-	mgr.Add(ctx, func(ctx context.Context) {
-		logger.Info("buildermgr.NSWatcher: started",
-			zap.String("label", utils.ManagedNamespaceLabelSelector()))
-		factory.Start(ctx.Done())
-		factory.WaitForCacheSync(ctx.Done())
-		logger.Info("buildermgr.NSWatcher: cache synced — watching for new namespaces")
-		<-ctx.Done()
-		logger.Info("buildermgr.NSWatcher: stopped")
-	})
+	utils.StartManagedNamespaceWatcher(ctx, logger, "buildermgr.NSWatcher", kubeClient, mgr, utils.NewNamespaceWatcherEventHandlers(ctx, logger, "buildermgr.NSWatcher", nsManager, utils.NamespaceRemovalStrategyTrackOnly))
 }

pkg/executor/multitenant/ns_watcher.go

@@ -65,11 +65,7 @@ import (
 	"time"
 
 	"go.uber.org/zap"
-	corev1 "k8s.io/api/core/v1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	k8sInformers "k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes"
-	k8sCache "k8s.io/client-go/tools/cache"
 
 	fv1 "github.com/fission/fission/pkg/apis/core/v1"
 	"github.com/fission/fission/pkg/executor/executortype"
@@ -96,30 +92,7 @@ func StartNSWatcher(
 	if err != nil {
 		logger.Error("multitenant.NSWatcher: BootstrapAndDispatch failed", zap.Error(err))
 	}
-
-	// Use a label-filtered informer so only Namespaces with our label are delivered.
-	// The resync period of 30m is standard for Fission informers — it re-lists to recover
-	// from any missed events, but normal operation is purely event-driven (no ticking).
-	factory := k8sInformers.NewSharedInformerFactoryWithOptions(
-		kubernetesClient,
-		30*time.Minute,
-		k8sInformers.WithTweakListOptions(func(opts *metav1.ListOptions) {
-			opts.LabelSelector = utils.ManagedNamespaceLabelSelector()
-		}),
-	)
-
-	nsInformer := factory.Core().V1().Namespaces().Informer()
-
-	_, _ = nsInformer.AddEventHandler(utils.NewNamespaceWatcherEventHandlers(ctx, logger, "multitenant.NSWatcher", nsManager, utils.NamespaceRemovalStrategyTrackOnly))
-
-	mgr.Add(ctx, func(ctx context.Context) {
-		logger.Info("multitenant.NSWatcher: started", zap.String("label", utils.ManagedNamespaceLabelSelector()))
-		factory.Start(ctx.Done())
-		factory.WaitForCacheSync(ctx.Done())
-		logger.Info("multitenant.NSWatcher: cache synced — watching for new namespaces")
-		<-ctx.Done()
-		logger.Info("multitenant.NSWatcher: stopped")
-	})
+	utils.StartManagedNamespaceWatcher(ctx, logger, "multitenant.NSWatcher", kubernetesClient, mgr, utils.NewNamespaceWatcherEventHandlers(ctx, logger, "multitenant.NSWatcher", nsManager, utils.NamespaceRemovalStrategyTrackOnly))
 }
 
 // registerNamespace calls AddNamespace on every executor type for the given namespace.

pkg/router/ns_watcher.go

@@ -10,11 +10,7 @@ import (
 	"time"
 
 	"go.uber.org/zap"
-	corev1 "k8s.io/api/core/v1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	k8sInformers "k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes"
-	k8sCache "k8s.io/client-go/tools/cache"
 
 	"github.com/fission/fission/pkg/utils"
 	"github.com/fission/fission/pkg/utils/manager"
@@ -34,26 +30,5 @@ func StartNSWatcher(
 	if err != nil {
 		logger.Error("router.NSWatcher: BootstrapAndDispatch failed", zap.Error(err))
 	}
-
-	factory := k8sInformers.NewSharedInformerFactoryWithOptions(
-		kubeClient,
-		30*time.Minute,
-		k8sInformers.WithTweakListOptions(func(opts *metav1.ListOptions) {
-			opts.LabelSelector = utils.ManagedNamespaceLabelSelector()
-		}),
-	)
-
-	nsInformer := factory.Core().V1().Namespaces().Informer()
-
-	_, _ = nsInformer.AddEventHandler(utils.NewNamespaceWatcherEventHandlers(ctx, logger, "router.NSWatcher", nsManager, utils.NamespaceRemovalStrategyTrackOnly))
-
-	mgr.Add(ctx, func(ctx context.Context) {
-		logger.Info("router.NSWatcher: started",
-			zap.String("label", utils.ManagedNamespaceLabelSelector()))
-		factory.Start(ctx.Done())
-		factory.WaitForCacheSync(ctx.Done())
-		logger.Info("router.NSWatcher: cache synced — watching for new namespaces")
-		<-ctx.Done()
-		logger.Info("router.NSWatcher: stopped")
-	})
+	utils.StartManagedNamespaceWatcher(ctx, logger, "router.NSWatcher", kubeClient, mgr, utils.NewNamespaceWatcherEventHandlers(ctx, logger, "router.NSWatcher", nsManager, utils.NamespaceRemovalStrategyTrackOnly))
 }

pkg/utils/namespace_manager.go

@@ -9,7 +9,12 @@ import (
 
 	"go.uber.org/zap"
 	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	k8sInformers "k8s.io/client-go/informers"
+	"k8s.io/client-go/kubernetes"
 	k8sCache "k8s.io/client-go/tools/cache"
+
+	managerPkg "github.com/fission/fission/pkg/utils/manager"
 )
 
 type NamespaceSubscriber interface {
@@ -207,6 +212,28 @@ func NewNamespaceWatcherEventHandlers(ctx context.Context, logger *zap.Logger, c
 	}
 }
 
+func StartManagedNamespaceWatcher(ctx context.Context, logger *zap.Logger, component string, kubeClient kubernetes.Interface, mgr managerPkg.Interface, handlers k8sCache.ResourceEventHandlerFuncs) {
+	factory := k8sInformers.NewSharedInformerFactoryWithOptions(
+		kubeClient,
+		30*time.Minute,
+		k8sInformers.WithTweakListOptions(func(opts *metav1.ListOptions) {
+			opts.LabelSelector = ManagedNamespaceLabelSelector()
+		}),
+	)
+
+	nsInformer := factory.Core().V1().Namespaces().Informer()
+	_, _ = nsInformer.AddEventHandler(handlers)
+
+	mgr.Add(ctx, func(ctx context.Context) {
+		logger.Info(component+": started", zap.String("label", ManagedNamespaceLabelSelector()))
+		factory.Start(ctx.Done())
+		factory.WaitForCacheSync(ctx.Done())
+		logger.Info(component + ": cache synced — watching for new namespaces")
+		<-ctx.Done()
+		logger.Info(component + ": stopped")
+	})
+}
+
 func (m *inMemoryNamespaceManager) Subscribe(subscriber NamespaceSubscriber) {
 	m.mu.Lock()
 	defer m.mu.Unlock()