layer1: add router namespace subscriber step 22

pkg/router/namespace_subscriber.go

@@ -0,0 +1,32 @@
+package main
+package router
+
+import (
+	"context"
+
+	"github.com/fission/fission/pkg/utils"
+	"github.com/fission/fission/pkg/utils/manager"
+)
+
+type routerNamespaceAdder interface {
+	AddNamespace(ctx context.Context, ns string, mgr manager.Interface) error
+}
+
+func NewNamespaceSubscriber(ts routerNamespaceAdder, mgr manager.Interface) utils.NamespaceSubscriber {
+	return utils.NamespaceSubscriberFuncs{
+		SubscriberName: "router",
+		AddFunc: func(ctx context.Context, record utils.NamespaceRecord) error {
+			return registerRouterNamespace(ctx, record.Name, ts, mgr)
+		},
+		ResyncFunc: func(ctx context.Context, record utils.NamespaceRecord) error {
+			return registerRouterNamespace(ctx, record.Name, ts, mgr)
+		},
+	}
+}
+
+func registerRouterNamespace(ctx context.Context, namespace string, ts routerNamespaceAdder, mgr manager.Interface) error {
+	if namespace == "" || ts == nil {
+		return nil
+	}
+	return ts.AddNamespace(ctx, namespace, mgr)
+}