使用Patch方式更新K8S的 API Objects 一共有三种方式：strategic merge patch, json-patch,json merge patch。关于这三种方式的文字描述区别可看官方文档update-api-object-kubectl-patch。
我在本文中主要会介绍使用client-go的Patch方式，主要包括strategic merge patch和json-patch。不介绍json merge patch的原因，是该方式使用场景比较少，因此不做介绍，如果有同学有兴趣，可做补充。
StrategicMergePatch
新增Object值
本次示例以给一个node新增一个labels为例，直接上代码：
//根据Pod Sn 更新 pod
func UpdatePodByPodSn(coreV1 v1.CoreV1Interface, podSn string, patchData map[string]interface{}) (*apiv1.Pod, error) {
v1Pod, err := coreV1.Pods("").Get(podSn, metav1.GetOptions{})
if err != nil {
logs.Error("[UpdatePodByPodSn] get pod %v fail %v", podSn, err)
return nil, fmt.Errorf("[UpdatePodByPodSn] get pod %v fail %v", podSn, err)
}
namespace := v1Pod.Namespace
podName := v1Pod.Name
playLoadBytes, _ := json.Marshal(patchData)
newV1Pod, err := coreV1.Pods(namespace).Patch(podName, types.StrategicMergePatchType, playLoadBytes)
if err != nil {
logs.Error("[UpdatePodByPodSn] %v pod Patch fail %v", podName, err)
return nil, fmt.Errorf("[UpdatePodByPodSn] %v pod Patch fail %v", podName, err)
}
return newV1Pod, nil
}
注意：上面的PatchData 必须是以
{"metadata":...}的go struct, 如：`map[string]interface{}{"metadata": map[string]map[string]string{"labels": {
"test2": "test2",
}}}`
对应单元测试用例
func pod(podName string, nodeName string, labels map[string]string, annotations map[string]string) *v1.Pod {
return &v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: podName, Labels: labels, Annotations: annotations}, Spec: v1.PodSpec{NodeName: nodeName}, Status: v1.PodStatus{}}
}
func TestUpdatePodByPodSn(t *testing.T) {
var tests = []struct {
expectedError interface{}
expectedAnnotation string
expectedLabel string
podSn string
patchData map[string]interface{}
v1Pod []runtime.Object
}{
{nil, "test2", "", "1.1.1.1", map[string]interface{}{"metadata": map[string]map[string]string{"annotations": {
"test2": "test2",
}}},
[]runtime.Object{pod("1.1.1.1", "1.1.1.1", map[string]string{"test1": "test1"}, map[string]string{"test1": "test1"})},
},
{nil, "", "", "1.1.1.2", map[string]interface{}{"metadata": map[string]map[string]string{"labels": {
"test2": "",
}}},
[]runtime.Object{pod("1.1.1.2", "1.1.1.1", map[string]string{"test1": "test1"}, map[string]string{"test1": "test1"})},
},
{nil, "", "test2", "1.1.1.3", map[string]interface{}{"metadata": map[string]map[string]string{"labels": {
"test2": "test2",
}}},
[]runtime.Object{pod("1.1.1.3", "1.1.1.1", map[string]string{"test1": "test1"}, map[string]string{"test1": "test1"})},
},
}
for _, test := range tests {
client := fake.NewSimpleClientset(test.v1Pod...)
v1Pod, err := UpdatePodByPodSn(client.CoreV1(), test.podSn, test.patchData)
if err != nil {
t.Errorf("expected error %s, got %s", test.expectedError, err)
}
assert.Equal(t, v1Pod.Annotations["test2"], test.expectedAnnotation)
assert.Equal(t, v1Pod.Labels["test2"], test.expectedLabel)
}
}修改Object的值
修改Obejct的值使用方式如下，当使用strategic merge patch的时候，如果提交的数据中键已经存在，那就会使用新提交的值替换原先的数据。依旧以修改labels的值为例。
如新提交的数据为：
{
"metadata":{
"labels":{
"test2":"test3",
},
}
}Node中已经存在的labels为：
{
"metadata":{
"labels":{
"test2":"test1",
},
}
}
最终Node中labels的key为test2的值会被替换成 test3。
删除Object值
当需要把某个Object的值删除的时候，当使用strategic merge patch的时候，依旧是删除labels为例提交方式是：
golang里面的表现形式是：
{
"metadata":{
"labels":{
"test2":nil
},
}
}对应从浏览器提交的数据是：
{
"metadata":{
"labels":{
"test2":null
},
}
}
PS：如果不喜欢使用上面struct的方式组成数据，可以使用如下的方式 labelsPatch := fmt.Sprintf({"metadata":{"labels":{"%s":"%s"}}}, labelkey, labelvalue) 直接代替上面示例中的patchData
JSONPatch
JSONPatch的详细说明请参考文档：http://jsonpatch.com/。
JSONPatch 主要有三种操作方式：add,replace,remove。以下会以代码示例说明这三种操作在Client-go对应的代码示例来说明怎样操作K8s 的资源。
使用JSONPatch，如果Patch中带有斜杠“/”和 (~)这两个字符，不能直接传入这两个字符，需要你输入的时候就人工转换下，/转换成~1，~转换成~0。以新增labels为例，如我要新增一个"test1/test2":"test3"的labels，可以把要传入的数据修改为"test1~1test2":"test3"即可。
Op:add
使用JSONPatch的方式新增一个标签，其提交的数据格式必须是[{ "op": "replace", "path": "/baz", "value": "boo" }] 这样的。代码如下：
//patchStringValue specifies a patch operation for a string.
type PatchStringValue struct {
Op string `json:"op"`
Path string `json:"path"`
Value interface{} `json:"value"`
}
type PatchNodeParam struct {
coreV1 v1.CoreV1Interface
NodeSn string `json:"nodeSn"`
OperatorType string `json:"operator_type"`
OperatorPath string `json:"operator_path"`
OperatorData map[string]interface{} `json:"operator_data"`
}
//patch node info, example label, annotation
func patchNode(param PatchNodeParam) (*apiv1.Node, error) {
coreV1 := param.coreV1
nodeSn := param.NodeSn
node, err := coreV1.Nodes().Get(nodeSn, metav1.GetOptions{})
if err != nil {
return nil, err
}
operatorData := param.OperatorData
operatorType := param.OperatorType
operatorPath := param.OperatorPath
var payloads []interface{}
for key, value := range operatorData {
payload := PatchStringValue{
Op: operatorType,
Path: operatorPath + key,
Value: value,
}
payloads = append(payloads, payload)
}
payloadBytes, _ := json.Marshal(payloads)
newNode, err := coreV1.Nodes().Patch(nodeSn, types.JSONPatchType, payloadBytes)
if err != nil {
return nil, err
}
return newNode, err
}单元测试：
func TestPatchNode(t *testing.T) {
Convey("test patchNode", t, func() {
Convey("Patch Node fail", func() {
var tests = []struct {
nodeSn string
operatorType string
operatorPath string
operatorData map[string]interface{}
expectedError interface{}
expectedValue *v1.Node
objs []runtime.Object
}{
{"1.1.1.1", "add", "/metadata/labels/",
map[string]interface{}{
"test1": "test1",
"test2": "test2"},
"nodes \"1.1.1.1\" not found", nil, nil},
{"1.1.1.1", "aaa", "/metadata/labels/",
map[string]interface{}{
"test1": "test1",
"test2": "test2"},
"Unexpected kind: aaa", nil, []runtime.Object{node("1.1.1.1", nil, nil)}},
}
for _, test := range tests {
client := fake.NewSimpleClientset(test.objs...)
param := PatchNodeParam{
coreV1: client.CoreV1(),
NodeSn: test.nodeSn,
OperatorType: test.operatorType,
OperatorPath: test.operatorPath,
OperatorData: test.operatorData,
EmpId: test.empId,
}
output, err := patchNode(param)
So(output, ShouldEqual, test.expectedValue)
So(err.Error(), ShouldEqual, test.expectedError)
}
})
Convey("Patch Node success", func() {
var tests = []struct {
nodeSn string
operatorType string
operatorPath string
operatorData map[string]interface{}
expectedError interface{}
expectedValue string
objs []runtime.Object
}{
{"1.1.1.1", "add", "/metadata/labels/",
map[string]interface{}{
"test1": "test1",
"test2": "test2"},
nil, "1.1.1.1", []runtime.Object{node("1.1.1.1", map[string]string{"test3": "test3"}, map[string]string{"test3": "test3"})}},
{"1.1.1.1", "add", "/metadata/labels/",
map[string]interface{}{
"test1": "test1",
"test2": "test2"},
nil, "1.1.1.1", []runtime.Object{node("1.1.1.1", map[string]string{"test1": "modifytest"}, map[string]string{"test1": "modifytest"})}},
}
for _, test := range tests {
client := fake.NewSimpleClientset(test.objs...)
param := PatchNodeParam{
coreV1: client.CoreV1(),
NodeSn: test.nodeSn,
OperatorType: test.operatorType,
OperatorPath: test.operatorPath,
OperatorData: test.operatorData,
}
output, err := patchNode(param)
So(output, ShouldNotBeNil)
So(err, ShouldBeNil)
So(output.Name, ShouldEqual, test.expectedValue)
}
})
})
}使用add有个需要注意的地方就是，当你的Path是使用的/metadata/labels而不是/metadata/labels/labelkey的时候，那你这个add操作实际是对整个labels进行替换，而不是新增，一定要注意避免踩坑。
PS：如果不喜欢使用上面struct的方式组成数据，可以使用如下的方式 labelsPatch := fmt.Sprintf([{"op":"add","path":"/metadata/labels/%s","value":"%s" }], labelkey, labelvalue) 直接代替上面示例中的patchData
Op:remove
要删除一个标签的话，代码和增加区别不大，唯一的区别就是提交的数据要由键值对修改为提交一个string slice类型[]string，代码如下：
type PatchNodeParam struct {
coreV1 v1.CoreV1Interface
NodeSn string `json:"nodeSn"`
OperatorType string `json:"operator_type"`
OperatorPath string `json:"operator_path"`
OperatorData map[string]interface{} `json:"operator_data"`
}
//patchStringValue specifies a remove operation for a string.
type RemoveStringValue struct {
Op string `json:"op"`
Path string `json:"path"`
}
//remove node info, example label, annotation
func removeNodeInfo(param RemoveNodeInfoParam) (*apiv1.Node, error) {
coreV1 := param.coreV1
nodeSn := param.NodeSn
node, err := coreV1.Nodes().Get(nodeSn, metav1.GetOptions{})
if err != nil {
return nil, err
}
operatorKey := param.OperatorKey
operatorType := param.OperatorType
operatorPath := param.OperatorPath
var payloads []interface{}
for key := range operatorKey {
payload := RemoveStringValue{
Op: operatorType,
Path: operatorPath + operatorKey[key],
}
payloads = append(payloads, payload)
}
payloadBytes, _ := json.Marshal(payloads)
newNode, err := coreV1.Nodes().Patch(nodeSn, types.JSONPatchType, payloadBytes)
if err != nil {
return nil, err
}
return newNode, err
}Op:replace
replace操作，会对整个的Object进行替换。所以使用replace记住要把原始的数据取出来和你要新增的数据合并后再提交，如：
type ReplaceNodeInfoParam struct {
coreV1 v1.CoreV1Interface
NodeSn string `json:"nodeSn"`
OperatorType string `json:"operator_type"`
OperatorPath string `json:"operator_path"`
OperatorData map[string]interface{} `json:"operator_data"`
DataType string `json:"data_type"`
}
//patchStringValue specifies a patch operation for a string.
type PatchStringValue struct {
Op string `json:"op"`
Path string `json:"path"`
Value interface{} `json:"value"`
}
func replaceNodeInfo(param ReplaceNodeInfoParam) (*apiv1.Node, error) {
coreV1 := param.coreV1
nodeSn := param.NodeSn
node, err := coreV1.Nodes().Get(nodeSn, metav1.GetOptions{})
if err != nil {
return nil, err
}
var originOperatorData map[string]string
dataType := param.DataType
operatorData := param.OperatorData
operatorType := param.OperatorType
operatorPath := param.OperatorPath
switch dataType {
case "labels":
originOperatorData = node.Labels
case "annotations":
originOperatorData = node.Annotations
default:
originOperatorData = nil
}
if originOperatorData == nil {
return nil, fmt.Errorf("[replaceNodeInfo] fail, %v originOperatorData is nil", nodeSn)
}
for key, value := range originOperatorData {
operatorData[key] = value
}
var payloads []interface{}
payload := PatchStringValue{
Op: operatorType,
Path: operatorPath,
Value: operatorData,
}
payloads = append(payloads, payload)
payloadBytes, _ := json.Marshal(payloads)
newNode, err := coreV1.Nodes().Patch(nodeSn, types.JSONPatchType, payloadBytes)
if err != nil {
return nil, err
}
return newNode, err
}
单元测试
func TestReplaceNodeInfo(t *testing.T) {
Convey("test ReplaceNodeInfo", t, func() {
Convey("Patch ReplaceNodeInfo fail", func() {
var tests = []struct {
nodeSn string
operatorType string
operatorPath string
dataType string
operatorData map[string]interface{}
expectedError interface{}
expectedValue *v1.Node
objs []runtime.Object
}{
{"1.1.1.1", "add", "/metadata/labels", "labels",
map[string]interface{}{
"test1": "test1",
"test2": "test2"},
"nodes \"1.1.1.1\" not found", nil, nil},
{"1.1.1.1", "aaa", "/metadata/annotations", "annotations",
map[string]interface{}{
"test1": "test1",
"test2": "test2"},
"[replaceNodeInfo] fail, 1.1.1.1 originOperatorData is nil", nil, []runtime.Object{node("1.1.1.1", nil, nil)}},
}
for _, test := range tests {
client := fake.NewSimpleClientset(test.objs...)
param := ReplaceNodeInfoParam{
coreV1: client.CoreV1(),
NodeSn: test.nodeSn,
OperatorType: test.operatorType,
OperatorPath: test.operatorPath,
OperatorData: test.operatorData,
DataType: test.dataType,
}
output, err := replaceNodeInfo(param)
So(output, ShouldEqual, test.expectedValue)
So(err.Error(), ShouldEqual, test.expectedError)
}
})
Convey("Patch Node success", func() {
var tests = []struct {
nodeSn string
operatorType string
operatorPath string
dataType string
operatorData map[string]interface{}
expectedError interface{}
expectedLabel string
expectedAnnotation string
objs []runtime.Object
}{
{"1.1.1.1", "replace", "/metadata/labels", "labels",
map[string]interface{}{
"test1": "test1",
"test2": "test2"},
nil, "test3", "", []runtime.Object{node("1.1.1.1", map[string]string{"test3": "test3"}, map[string]string{"test3": "test3"})}},
{"1.1.1.1", "replace", "/metadata/annotations", "annotations",
map[string]interface{}{
"test1": "test1",
"test2": "test2"},
nil, "", "modifytest", []runtime.Object{node("1.1.1.1", map[string]string{"test1": "modifytest"}, map[string]string{"test1": "modifytest"})}},
}
for _, test := range tests {
client := fake.NewSimpleClientset(test.objs...)
param := ReplaceNodeInfoParam{
coreV1: client.CoreV1(),
NodeSn: test.nodeSn,
OperatorType: test.operatorType,
OperatorPath: test.operatorPath,
OperatorData: test.operatorData,
DataType: test.dataType,
}
output, err := replaceNodeInfo(param)
So(output, ShouldNotBeNil)
So(err, ShouldBeNil)
So(output.Labels["test3"], ShouldEqual, test.expectedLabel)
So(output.Annotations["test1"], ShouldEqual, test.expectedAnnotation)
}
})
})
}PS：如各位还有其他更好的方式，欢迎交流补充。