fix(coordinator): fix config marshaling error (#560)

### Motivation 

Fix coordinator config marshalling error.


### Modification

- filter unsupported json type

coordinator/coordinator.go

@@ -31,15 +31,15 @@ import (
 type Config struct {
 	InternalServiceAddr              string
 	InternalSecureServiceAddr        string
-	PeerTLS                          *tls.Config
-	ServerTLS                        *tls.Config
+	PeerTLS                          *tls.Config `json:"-"`
+	ServerTLS                        *tls.Config `json:"-"`
 	MetricsServiceAddr               string
 	MetadataProviderImpl             MetadataProviderImpl
 	K8SMetadataNamespace             string
 	K8SMetadataConfigMapName         string
 	FileMetadataPath                 string
-	ClusterConfigProvider            func() (model.ClusterConfig, error)
-	ClusterConfigChangeNotifications chan any
+	ClusterConfigProvider            func() (model.ClusterConfig, error) `json:"-"`
+	ClusterConfigChangeNotifications chan any                            `json:"-"`
 }
 
 type MetadataProviderImpl string

coordinator/coordinator_test.go

@@ -0,0 +1,32 @@
+// Copyright 2024 StreamNative, Inc.
+//
+// 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 coordinator
+
+import (
+	"encoding/json"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestCoordinator_MarshalingError(t *testing.T) {
+	config := Config{
+		InternalServiceAddr:       "123",
+		InternalSecureServiceAddr: "123",
+		MetadataProviderImpl:      "123",
+		K8SMetadataConfigMapName:  "123",
+	}
+	_, err := json.Marshal(config)
+	assert.Nil(t, err)
+}