client-go连接kubernetes集群-update相关操作

Posted 2022-05-10 saynaihe

背景：

紧接client-go连接kubernetes集群-connect and list，client-go连接kubernetes集群-create相关操作。实例都是拿namespace 和deployment两个为代表进行展开延伸的（个人环境中deployment还是具有代表性的），前面创建了namespace deployment，正常的流程下一步就是修改namespace and deployment 了！

client-go连接kubernetes集群-update相关操作

1. namespace的update

参照create

先看一眼&corev1.Namespace metav1.ObjectMeta中都有哪些配置可以修改,metav1.ObjectMeta填充一下所有字段：

Name还是默认的zhangpeng namespace了，我添加一个labels？



main.go

package main

import (
	"context"
	"flag"
	"fmt"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/clientcmd"
	"k8s.io/client-go/util/homedir"
	"path/filepath"
)

func main() 
	var kubeconfig *string
	if home := homedir.HomeDir(); home != "" 
		kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
	 else 
		kubeconfig = flag.String("kubeconfig", "", "absolute path to the kubeconfig file")
	
	flag.Parse()
	config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
	if err != nil 
		panic(err.Error())
	

	// create the clientset
	clientset, err := kubernetes.NewForConfig(config)
	if err != nil 
		panic(err.Error())
	
	namespace := &corev1.Namespace
		ObjectMeta: metav1.ObjectMeta
			Name:                       "zhangpeng",
			GenerateName:               "",
			Namespace:                  "",
			SelfLink:                   "",
			UID:                        "",
			ResourceVersion:            "",
			Generation:                 0,
			CreationTimestamp:          metav1.Time,
			DeletionTimestamp:          nil,
			DeletionGracePeriodSeconds: nil,
			Labels: map[string]string
				"dev": "test",
			,
			Annotations:     nil,
			OwnerReferences: nil,
			Finalizers:      nil,
			ClusterName:     "",
			ManagedFields:   nil,
		,
	
	result, _ := clientset.CoreV1().Namespaces().Update(context.TODO(), namespace, metav1.UpdateOptions)
	fmt.Println(result)

运行main.go


登录某云后台确认生成label！这里正好看到了自愿配额与限制？正巧最近在看文章的时候看到一个这样的例子：基于client-go操作namespace资源配额设计

2. 扩展一下resourcequotas

main.go

package main

import (
	"context"
	"flag"
	"fmt"
	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/resource"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/clientcmd"
	"k8s.io/client-go/util/homedir"
	"path/filepath"
)

func main() 
	var kubeconfig *string
	if home := homedir.HomeDir(); home != "" 
		kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
	 else 
		kubeconfig = flag.String("kubeconfig", "", "absolute path to the kubeconfig file")
	
	flag.Parse()
	config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
	if err != nil 
		panic(err.Error())
	

	// create the clientset
	clientset, err := kubernetes.NewForConfig(config)
	if err != nil 
		panic(err.Error())
	
	namespace := &corev1.Namespace
		ObjectMeta: metav1.ObjectMeta
			Name:                       "zhangpeng",
			GenerateName:               "",
			Namespace:                  "",
			SelfLink:                   "",
			UID:                        "",
			ResourceVersion:            "",
			Generation:                 0,
			CreationTimestamp:          metav1.Time,
			DeletionTimestamp:          nil,
			DeletionGracePeriodSeconds: nil,
			Labels: map[string]string
				"dev": "test",
			,
			Annotations:     nil,
			OwnerReferences: nil,
			Finalizers:      nil,
			ClusterName:     "",
			ManagedFields:   nil,
		,
	
	result, _ := clientset.CoreV1().Namespaces().Update(context.TODO(), namespace, metav1.UpdateOptions)
	fmt.Println(result)
	quotaTest := clientset.CoreV1().ResourceQuotas("zhangpeng")
	quota := &corev1.ResourceQuota
		ObjectMeta: metav1.ObjectMeta
			Name: "quota-namespace",
		,
		Spec: corev1.ResourceQuotaSpec
			Hard: map[corev1.ResourceName]resource.Quantity
				corev1.ResourceLimitsCPU:      resource.MustParse("200m"),
				corev1.ResourceLimitsMemory:   resource.MustParse("200M"),
				corev1.ResourceRequestsCPU:    resource.MustParse("1000m"),
				corev1.ResourceRequestsMemory: resource.MustParse("1Gi"),
			,
		,
	

	result1, err := quotaTest.Create(context.TODO(), quota, metav1.CreateOptions)
	if err != nil 
		fmt.Println(err)
	 else 
		fmt.Println(result1)
	

kubectl get resourcequotas -n zhangpeng

3. update deployment

参照：client-go连接kubernetes集群-create相关操作，生成yaml读取文件流的方式：
修改nginx镜像tag为1.16
src/yamls/nginx.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: nginx
  name: nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  strategy: 
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: nginx
    spec:
      containers:
        - image: nginx:1.16
          name: nginx
          resources: 
status: 

现在如果直接运行肯定是already exists的！

修改main.go如下：

package main

import (
	"context"
	"encoding/json"
	"flag"
	"fmt"
	"io/ioutil"
	v1 "k8s.io/api/apps/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/yaml"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/clientcmd"
	"k8s.io/client-go/util/homedir"
	"path/filepath"
)

func main() 
	var kubeconfig *string
	if home := homedir.HomeDir(); home != "" 
		kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
	 else 
		kubeconfig = flag.String("kubeconfig", "", "absolute path to the kubeconfig file")
	
	flag.Parse()
	config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
	if err != nil 
		panic(err.Error())
	

	// create the clientset
	clientset, err := kubernetes.NewForConfig(config)
	if err != nil 
		panic(err.Error())
	
	b, err := ioutil.ReadFile("src/yamls/nginx.yaml")
	nginxDep := &v1.Deployment
	nginxJson, _ := yaml.ToJSON(b)
	if err = json.Unmarshal(nginxJson, nginxDep); err != nil 
		return
	
	if _, err = clientset.AppsV1().Deployments("zhangpeng").Update(context.Background(), nginxDep, metav1.UpdateOptions); err != nil 
		fmt.Println(err)
		return
	

运行main.go

kubectl get deployments -n zhangpeng -o yaml

强调：

1. context.Background() context.TODO()还是有点懵 分不清什么时候用…
2. 执行结果的返回没有一致格式化输出，以及一下错误的处理？