Avoid error log when unmarshalling config for MC controller

multicluster/cmd/multicluster-controller/options.go

@@ -28,7 +28,6 @@ import (
 
 	mcsv1alpha1 "antrea.io/antrea/multicluster/apis/multicluster/v1alpha1"
 	"antrea.io/antrea/multicluster/controllers/multicluster/common"
-	"antrea.io/antrea/pkg/util/yaml"
 )
 
 type Options struct {
@@ -123,25 +122,24 @@ func (o *Options) setDefaults() {
 	}
 }
 
-func (o *Options) loadConfigFromFile(multiclusterConfig *mcsv1alpha1.MultiClusterConfig) error {
-	data, err := os.ReadFile(o.configFile)
-	if err != nil {
-		return err
-	}
+func (o *Options) loadConfig(data []byte, multiclusterConfig *mcsv1alpha1.MultiClusterConfig) error {
 	codecs := serializer.NewCodecFactory(scheme)
-	if err := yaml.UnmarshalLenient(data, multiclusterConfig); err != nil {
-		return err
-	}
-	if err = runtime.DecodeInto(codecs.UniversalDecoder(), data, multiclusterConfig); err != nil {
+	if err := runtime.DecodeInto(codecs.UniversalDecoder(), data, multiclusterConfig); err != nil {
 		return err
 	}
-
 	if multiclusterConfig.Metrics.BindAddress != "" {
 		o.options.Metrics.BindAddress = multiclusterConfig.Metrics.BindAddress
 	}
 	if multiclusterConfig.Health.HealthProbeBindAddress != "" {
 		o.options.HealthProbeBindAddress = multiclusterConfig.Health.HealthProbeBindAddress
 	}
-
 	return nil
 }
+
+func (o *Options) loadConfigFromFile(multiclusterConfig *mcsv1alpha1.MultiClusterConfig) error {
+	data, err := os.ReadFile(o.configFile)
+	if err != nil {
+		return err
+	}
+	return o.loadConfig(data, multiclusterConfig)
+}

multicluster/cmd/multicluster-controller/options_test.go

@@ -19,6 +19,10 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"k8s.io/apimachinery/pkg/util/yaml"
+
+	"antrea.io/antrea/multicluster"
+	mcsv1alpha1 "antrea.io/antrea/multicluster/apis/multicluster/v1alpha1"
 )
 
 func TestComplete(t *testing.T) {
@@ -85,3 +89,19 @@ func TestComplete(t *testing.T) {
 		})
 	}
 }
+
+func TestUnmarshalDefaultConfig(t *testing.T) {
+	configBytes := multicluster.DefaultControllerManagerConfigBytes
+	var multiclusterConfig mcsv1alpha1.MultiClusterConfig
+	// Note that we use UnmarshalStrict from k8s.io/apimachinery/pkg/util/yaml, which will first
+	// convert the YAML data to JSON. The mcsv1alpha1.MultiClusterConfig struct definition does
+	// not have yaml tags.
+	assert.NoError(t, yaml.UnmarshalStrict(configBytes, &multiclusterConfig), "Default config should unmarshal correctly")
+}
+
+func TestLoadConfig(t *testing.T) {
+	configBytes := multicluster.DefaultControllerManagerConfigBytes
+	var multiclusterConfig mcsv1alpha1.MultiClusterConfig
+	o := newOptions()
+	assert.NoError(t, o.loadConfig(configBytes, &multiclusterConfig))
+}

multicluster/embed.go

@@ -0,0 +1,19 @@
+// Copyright 2024 Antrea 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 multicluster
+
+import _ "embed"
+
+//go:embed config/default/configmap/controller_manager_config.yaml
+var DefaultControllerManagerConfigBytes []byte