diff --git a/contrib/config/kubernetes/config_test.go b/contrib/config/kubernetes/config_test.go
index bd0a605a8..6cdb1c98c 100644
--- a/contrib/config/kubernetes/config_test.go
+++ b/contrib/config/kubernetes/config_test.go
@@ -1,18 +1,44 @@
 package kubernetes
 
 import (
+	"context"
 	"log"
 	"path/filepath"
+	"reflect"
+	"strings"
 	"testing"
 
 	"github.com/go-kratos/kratos/v2/config"
+
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
 	"k8s.io/client-go/util/homedir"
 )
 
+const (
+	testKey   = "test_config.json"
+	namespace = "default"
+	name      = "test"
+)
+
+var (
+	keyPath    = strings.Join([]string{namespace, name, testKey}, "/")
+	objectMeta = metav1.ObjectMeta{
+		Name:      name,
+		Namespace: namespace,
+		Labels: map[string]string{
+			"app": "test",
+		},
+	}
+)
+
 func TestSource(t *testing.T) {
 	home := homedir.HomeDir()
 	s := NewSource(
-		Namespace("mesh"),
+		Namespace("default"),
 		LabelSelector(""),
 		KubeConfig(filepath.Join(home, ".kube", "config")),
 	)
@@ -40,3 +66,143 @@ func ExampleNewSource() {
 		log.Panic(err)
 	}
 }
+
+func TestConfig(t *testing.T) {
+	restConfig, err := rest.InClusterConfig()
+	home := homedir.HomeDir()
+
+	options := []Option{
+		Namespace(namespace),
+		LabelSelector("app=test"),
+	}
+
+	if err != nil {
+		kubeconfig := filepath.Join(home, ".kube", "config")
+		restConfig, err = clientcmd.BuildConfigFromFlags("", kubeconfig)
+		if err != nil {
+			t.Fatal(err)
+		}
+		options = append(options, KubeConfig(kubeconfig))
+	}
+	clientSet, err := kubernetes.NewForConfig(restConfig)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	clientSetConfigMaps := clientSet.CoreV1().ConfigMaps(namespace)
+
+	source := NewSource(options...)
+	if _, err = clientSetConfigMaps.Create(context.Background(), &v1.ConfigMap{
+		ObjectMeta: objectMeta,
+		Data: map[string]string{
+			testKey: "test config",
+		},
+	}, metav1.CreateOptions{}); err != nil {
+		t.Fatal(err)
+	}
+
+	defer func() {
+		if err = clientSetConfigMaps.Delete(context.Background(), name, metav1.DeleteOptions{}); err != nil {
+			t.Error(err)
+		}
+	}()
+	kvs, err := source.Load()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(kvs) != 1 || kvs[0].Key != keyPath || string(kvs[0].Value) != "test config" {
+		t.Fatal("config error")
+	}
+
+	w, err := source.Watch()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		_ = w.Stop()
+	}()
+	// create also produce an event, discard it
+	if _, err = w.Next(); err != nil {
+		t.Fatal(err)
+	}
+
+	if _, err = clientSetConfigMaps.Update(context.Background(), &v1.ConfigMap{
+		ObjectMeta: objectMeta,
+		Data: map[string]string{
+			testKey: "new config",
+		},
+	}, metav1.UpdateOptions{}); err != nil {
+		t.Error(err)
+	}
+
+	if kvs, err = w.Next(); err != nil {
+		t.Fatal(err)
+	}
+
+	if len(kvs) != 1 || kvs[0].Key != keyPath || string(kvs[0].Value) != "new config" {
+		t.Fatal("config error")
+	}
+}
+
+func TestExtToFormat(t *testing.T) {
+	restConfig, err := rest.InClusterConfig()
+	home := homedir.HomeDir()
+
+	options := []Option{
+		Namespace(namespace),
+		LabelSelector("app=test"),
+	}
+
+	if err != nil {
+		kubeconfig := filepath.Join(home, ".kube", "config")
+		restConfig, err = clientcmd.BuildConfigFromFlags("", kubeconfig)
+		if err != nil {
+			t.Fatal(err)
+		}
+		options = append(options, KubeConfig(kubeconfig))
+	}
+	clientSet, err := kubernetes.NewForConfig(restConfig)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	clientSetConfigMaps := clientSet.CoreV1().ConfigMaps(namespace)
+
+	tc := `{"a":1}`
+	if _, err = clientSetConfigMaps.Create(context.Background(), &v1.ConfigMap{
+		ObjectMeta: objectMeta,
+		Data: map[string]string{
+			testKey: tc,
+		},
+	}, metav1.CreateOptions{}); err != nil {
+		t.Fatal(err)
+	}
+
+	defer func() {
+		if err = clientSetConfigMaps.Delete(context.Background(), name, metav1.DeleteOptions{}); err != nil {
+			t.Error(err)
+		}
+	}()
+
+	source := NewSource(options...)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	kvs, err := source.Load()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(len(kvs), 1) {
+		t.Errorf("len(kvs) = %d", len(kvs))
+	}
+	if !reflect.DeepEqual(keyPath, kvs[0].Key) {
+		t.Errorf("kvs[0].Key is %s", kvs[0].Key)
+	}
+	if !reflect.DeepEqual(tc, string(kvs[0].Value)) {
+		t.Errorf("kvs[0].Value is %s", kvs[0].Value)
+	}
+	if !reflect.DeepEqual("json", kvs[0].Format) {
+		t.Errorf("kvs[0].Format is %s", kvs[0].Format)
+	}
+}