layer1: add default watcher config helper

doc/thinking/2026-04-26-namespace-manager-step51.md

@@ -0,0 +1,18 @@
+# 2026-04-26 — NamespaceManager rewrite, step 51
+
+## Цель шага
+
+Убрать из call sites повторение стандартного config для managed namespace watcher-а.
+
+## Что меняем
+
+1. Добавляем `NewDefaultManagedNamespaceWatcherConfig()`.
+2. Helper подставляет:
+   - `DefaultNSResolver().Snapshot()`;
+   - `track-only` как default removal strategy.
+3. `buildermgr`, `router`, `executor/multitenant` используют helper.
+
+## Что НЕ меняем
+
+- не меняем runtime semantics;
+- не меняем subscriber logic.

pkg/buildermgr/ns_watcher.go

@@ -25,12 +25,7 @@ func StartNSWatcher(
 	pkgw *packageWatcher,
 	mgr manager.Interface,
 ) {
-	_, err := utils.RunManagedNamespaceWatcher(ctx, logger, kubeClient, mgr, utils.ManagedNamespaceWatcherConfig{
-		Component:       "buildermgr.NSWatcher",
-		Namespaces:      utils.DefaultNSResolver().Snapshot(),
-		RemovalStrategy: utils.NamespaceRemovalStrategyTrackOnly,
-		Subscriber:      NewNamespaceSubscriber(envw, pkgw, mgr),
-	})
+	_, err := utils.RunManagedNamespaceWatcher(ctx, logger, kubeClient, mgr, utils.NewDefaultManagedNamespaceWatcherConfig("buildermgr.NSWatcher", NewNamespaceSubscriber(envw, pkgw, mgr)))
 	if err != nil {
 		logger.Error("buildermgr.NSWatcher: BootstrapAndDispatch failed", zap.Error(err))
 	}

pkg/executor/multitenant/ns_watcher.go

@@ -86,12 +86,7 @@ func StartNSWatcher(
 	executorTypes map[fv1.ExecutorType]executortype.ExecutorType,
 	mgr manager.Interface,
 ) {
-	_, err := utils.RunManagedNamespaceWatcher(ctx, logger, kubernetesClient, mgr, utils.ManagedNamespaceWatcherConfig{
-		Component:       "multitenant.NSWatcher",
-		Namespaces:      utils.DefaultNSResolver().Snapshot(),
-		RemovalStrategy: utils.NamespaceRemovalStrategyTrackOnly,
-		Subscriber:      NewNamespaceSubscriber(logger, kubernetesClient, executorTypes, mgr),
-	})
+	_, err := utils.RunManagedNamespaceWatcher(ctx, logger, kubernetesClient, mgr, utils.NewDefaultManagedNamespaceWatcherConfig("multitenant.NSWatcher", NewNamespaceSubscriber(logger, kubernetesClient, executorTypes, mgr)))
 	if err != nil {
 		logger.Error("multitenant.NSWatcher: BootstrapAndDispatch failed", zap.Error(err))
 	}

pkg/router/ns_watcher.go

@@ -24,12 +24,7 @@ func StartNSWatcher(
 	ts *HTTPTriggerSet,
 	mgr manager.Interface,
 ) {
-	_, err := utils.RunManagedNamespaceWatcher(ctx, logger, kubeClient, mgr, utils.ManagedNamespaceWatcherConfig{
-		Component:       "router.NSWatcher",
-		Namespaces:      utils.DefaultNSResolver().Snapshot(),
-		RemovalStrategy: utils.NamespaceRemovalStrategyTrackOnly,
-		Subscriber:      NewNamespaceSubscriber(ts, mgr),
-	})
+	_, err := utils.RunManagedNamespaceWatcher(ctx, logger, kubeClient, mgr, utils.NewDefaultManagedNamespaceWatcherConfig("router.NSWatcher", NewNamespaceSubscriber(ts, mgr)))
 	if err != nil {
 		logger.Error("router.NSWatcher: BootstrapAndDispatch failed", zap.Error(err))
 	}

pkg/utils/namespace_manager.go

@@ -110,6 +110,15 @@ func NewWatcherNamespaceManager(ctx context.Context, namespaces []string, source
 	return manager, err
 }
 
+func NewDefaultManagedNamespaceWatcherConfig(component string, subscriber NamespaceSubscriber) ManagedNamespaceWatcherConfig {
+	return ManagedNamespaceWatcherConfig{
+		Component:       component,
+		Namespaces:      DefaultNSResolver().Snapshot(),
+		RemovalStrategy: NamespaceRemovalStrategyTrackOnly,
+		Subscriber:      subscriber,
+	}
+}
+
 func PrepareManagedNamespaceWatcher(ctx context.Context, logger *zap.Logger, config ManagedNamespaceWatcherConfig) (NamespaceManager, k8sCache.ResourceEventHandlerFuncs, error) {
 	strategy := config.RemovalStrategy
 	if strategy == "" {

pkg/utils/namespace_manager_test.go

@@ -485,6 +485,30 @@ func TestRunManagedNamespaceWatcher(t *testing.T) {
 	}
 }
 
+func TestNewDefaultManagedNamespaceWatcherConfig(t *testing.T) {
+	resolver := DefaultNSResolver()
+	original := resolver.FissionResourceNS
+	resolver.FissionResourceNS = map[string]string{"tenant-a": "tenant-a"}
+	defer func() {
+		resolver.FissionResourceNS = original
+	}()
+
+	router := &testNamespaceSubscriber{name: "router"}
+	config := NewDefaultManagedNamespaceWatcherConfig("router.NSWatcher", router)
+	if config.Component != "router.NSWatcher" {
+		t.Fatalf("expected component name to be preserved")
+	}
+	if config.RemovalStrategy != NamespaceRemovalStrategyTrackOnly {
+		t.Fatalf("expected default removal strategy track-only")
+	}
+	if !reflect.DeepEqual([]string{"tenant-a"}, config.Namespaces) {
+		t.Fatalf("expected namespaces from resolver snapshot")
+	}
+	if config.Subscriber != router {
+		t.Fatalf("expected subscriber to be preserved")
+	}
+}
+
 func TestPrepareManagedNamespaceWatcherDefaultsToTrackOnly(t *testing.T) {
 	router := &testNamespaceSubscriber{name: "router"}
 	logger := zap.NewNop()