Move controller manager build function to pkg/epp/server so we can better test it

Author: hzxuzhonghu

Diff for: cmd/epp/main.go

@@ -30,20 +30,12 @@ import (
 	"go.uber.org/zap/zapcore"
 	"google.golang.org/grpc"
 	healthPb "google.golang.org/grpc/health/grpc_health_v1"
-	corev1 "k8s.io/api/core/v1"
-	"k8s.io/apimachinery/pkg/fields"
-	"k8s.io/apimachinery/pkg/runtime"
-	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
-	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/client-go/rest"
 	"k8s.io/component-base/metrics/legacyregistry"
 	ctrl "sigs.k8s.io/controller-runtime"
-	"sigs.k8s.io/controller-runtime/pkg/cache"
-	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
 	"sigs.k8s.io/controller-runtime/pkg/manager"
 	"sigs.k8s.io/controller-runtime/pkg/metrics/filters"
-	"sigs.k8s.io/gateway-api-inference-extension/api/v1alpha2"
 	"sigs.k8s.io/gateway-api-inference-extension/internal/runnable"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/backend"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/backend/vllm"
@@ -101,15 +93,9 @@ var (
 			"are assumed to be named tls.crt and tls.key, respectively. If not set, and secureServing is enabled, "+
 			"then a self-signed certificate is used.")
 
-	scheme   = runtime.NewScheme()
 	setupLog = ctrl.Log.WithName("setup")
 )
 
-func init() {
-	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
-	utilruntime.Must(v1alpha2.AddToScheme(scheme))
-}
-
 func main() {
 	if err := run(); err != nil {
 		os.Exit(1)
@@ -144,34 +130,9 @@ func run() error {
 		return err
 	}
 
-	mgr, err := ctrl.NewManager(cfg, ctrl.Options{
-		Scheme: scheme,
-		Cache: cache.Options{
-			ByObject: map[client.Object]cache.ByObject{
-				&corev1.Pod{}: {
-					Namespaces: map[string]cache.Config{
-						*poolNamespace: {},
-					},
-				},
-				&v1alpha2.InferencePool{}: {
-					Namespaces: map[string]cache.Config{
-						*poolNamespace: {
-							FieldSelector: fields.SelectorFromSet(fields.Set{
-								"metadata.name": *poolName,
-							}),
-						},
-					},
-				},
-				&v1alpha2.InferenceModel{}: {
-					Namespaces: map[string]cache.Config{
-						*poolNamespace: {},
-					},
-				},
-			},
-		},
-	})
+	mgr, err := runserver.NewDefaultManager(*poolNamespace, *poolName)
 	if err != nil {
-		setupLog.Error(err, "Failed to create controller manager", "config", cfg)
+		setupLog.Error(err, "Failed to create controller manager")
 		return err
 	}
 

Diff for: pkg/epp/server/controller_manager.go

@@ -0,0 +1,78 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package server
+
+import (
+	"fmt"
+
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/fields"
+	"k8s.io/apimachinery/pkg/runtime"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/cache"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/gateway-api-inference-extension/api/v1alpha2"
+)
+
+var scheme = runtime.NewScheme()
+
+func init() {
+	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
+	utilruntime.Must(v1alpha2.AddToScheme(scheme))
+}
+
+// NewDefaultManager creates a new controller manager with default configuration.
+func NewDefaultManager(namespace, name string) (ctrl.Manager, error) {
+	// Init runtime.
+	cfg, err := ctrl.GetConfig()
+	if err != nil {
+		return nil, fmt.Errorf("failed to create rest config: %v", err)
+	}
+
+	manager, err := ctrl.NewManager(cfg, ctrl.Options{
+		Scheme: scheme,
+		Cache: cache.Options{
+			ByObject: map[client.Object]cache.ByObject{
+				&corev1.Pod{}: {
+					Namespaces: map[string]cache.Config{
+						namespace: {},
+					},
+				},
+				&v1alpha2.InferencePool{}: {
+					Namespaces: map[string]cache.Config{
+						namespace: {
+							FieldSelector: fields.SelectorFromSet(fields.Set{
+								"metadata.name": name,
+							}),
+						},
+					},
+				},
+				&v1alpha2.InferenceModel{}: {
+					Namespaces: map[string]cache.Config{
+						namespace: {},
+					},
+				},
+			},
+		},
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed to create controller manager: %v", err)
+	}
+	return manager, nil
+}