k8s client-go 02操作k8s deployment
Clientset
构造clientset操作k8s集群。
package main import ( "context" "fmt" v1 "k8s.io/apimachinery/pkg/apis/meta/v1" "k8s.io/client-go/kubernetes" "k8s.io/client-go/tools/clientcmd" "log" ) func main() { // 1. 构造访问config的配置，从文件中加载，将 home目录下的 .kube/config拷贝到当前./conf/下 config, err := clientcmd.BuildConfigFromFlags("", "./conf/config") if err != nil { panic(err) } // 2. 创建clientset clientset, err := kubernetes.NewForConfig(config) if err != nil { panic(err) } // 3.对资源对象进行操作 podList, err := clientset.CoreV1().Pods("dev").List(context.Background(), v1.ListOptions{}) if err != nil { log.Printf("list pods error:%v\n", err) return } fmt.Println("dev pod count:", len(podList.Items)) for _, pod := range podList.Items { fmt.Printf("name: %s\n", pod.Name) } }
使用clientset创建pod
package main import ( "context" 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" "log" ) func main() { // 1. 构造访问config的配置，从文件中加载，将 home目录下的 .kube/config拷贝到当前./conf/下 config, err := clientcmd.BuildConfigFromFlags("", "./conf/config") if err != nil { panic(err) } // 2. 创建clientset clientset, err := kubernetes.NewForConfig(config) if err != nil { panic(err) } // 3.创建一个pod对象并填上字段 pod := corev1.Pod{ TypeMeta: metav1.TypeMeta{ APIVersion: "v1", Kind: "Pod", }, ObjectMeta: metav1.ObjectMeta{ Name: "nginx", Namespace: "default", Labels: map[string]string{ "run": "nginx", }, }, Spec: corev1.PodSpec{ Containers: []corev1.Container{ { Image: "nginx", Name: "nginx-container", Ports: []corev1.ContainerPort{ { ContainerPort: 80, }, }, }, }, }, } // 4. 创建pod _, err = clientset.CoreV1().Pods("default").Create(context.Background(), &pod, metav1.CreateOptions{}) if err != nil { log.Printf("create pod error:%v\n", err) return } log.Printf("create pod success\n") }
创建、更新、查询、删除Deployment
使用client-go，实现一个deployment的创建、更新和删除操作。代码依据官方的例子修改而来
package main import ( "bufio" "context" "fmt" appsv1 "k8s.io/api/apps/v1" corev1 "k8s.io/api/core/v1" v1 "k8s.io/apimachinery/pkg/apis/meta/v1" "k8s.io/client-go/kubernetes" appsresv1 "k8s.io/client-go/kubernetes/typed/apps/v1" "k8s.io/client-go/tools/clientcmd" "k8s.io/client-go/util/retry" "k8s.io/klog/v2" "os" ) func main() { // 1、创建配置文件 config, err := clientcmd.BuildConfigFromFlags("", "./conf/config") if err != nil { panic(err) } // 2、创建clientset clientset, err := kubernetes.NewForConfig(config) if err != nil { panic(err) } deployClient := clientset.AppsV1().Deployments(corev1.NamespaceDefault) // 3、创建deployment CreateDeploy(deployClient) prompt() // 4、更新deployment UpdateDeploy(deployClient) prompt() // 5、查询deployment ListDeploy(deployClient) prompt() // 6、删除deployment DeleteDeploy(deployClient) } func CreateDeploy(client appsresv1.DeploymentInterface) { klog.Info("CreateDeploy...........") replicas := int32(2) deploy := appsv1.Deployment{ TypeMeta: v1.TypeMeta{ Kind: "Deployment", APIVersion: "apps/v1", }, ObjectMeta: v1.ObjectMeta{ Name: "deploy-nginx-demo", Namespace: corev1.NamespaceDefault, }, Spec: appsv1.DeploymentSpec{ Replicas: &replicas, Selector: &v1.LabelSelector{ MatchLabels: map[string]string{ "app": "nginx", }, }, Template: corev1.PodTemplateSpec{ ObjectMeta: v1.ObjectMeta{ Name: "nginx", Labels: map[string]string{ "app": "nginx", }, }, Spec: corev1.PodSpec{ Containers: []corev1.Container{ { Name: "web", Image: "nginx:1.12", Ports: []corev1.ContainerPort{ { Protocol: corev1.ProtocolTCP, ContainerPort: 80, }, }, }, }, }, }, }, } dep, err := client.Create(context.Background(), &deploy, v1.CreateOptions{}) if err != nil { klog.Errorf("create deployment error:%v", err) return } klog.Infof("create deployment success, name:%s", dep.Name) } func UpdateDeploy(client appsresv1.DeploymentInterface) { klog.Info("UpdateDeploy...........") // 当有多个客户端对同一个资源进行操作时，可能会发生错误。使用RetryOnConflict来重试，重试相关参数由DefaultRetry来提供 err := retry.RetryOnConflict(retry.DefaultRetry, func() error { // 查询要更新的deploy deploy, err := client.Get(context.Background(), "deploy-nginx-demo", v1.GetOptions{}) if err != nil { klog.Errorf("can't get deployment, err:%v", err) return nil } // 修改参数后进行更新 replicas := int32(1) deploy.Spec.Replicas = &replicas deploy.Spec.Template.Spec.Containers[0].Image = "nginx:1.13" _, err = client.Update(context.Background(), deploy, v1.UpdateOptions{}) if err != nil { klog.Errorf("update deployment error, err:%v", err) } return err }) if err != nil { klog.Errorf("update deployment error, err:%v", err) } else { klog.Infof("update deployment success") } } func ListDeploy(client appsresv1.DeploymentInterface) { klog.Info("ListDeploy...........") deplist, err := client.List(context.Background(), v1.ListOptions{}) if err != nil { klog.Errorf("list deployment error, err:%v", err) return } for _, dep := range deplist.Items { klog.Infof("deploy name:%s, replicas:%d, container image:%s", dep.Name, *dep.Spec.Replicas, dep.Spec.Template.Spec.Containers[0].Image) } } func DeleteDeploy(client appsresv1.DeploymentInterface) { klog.Info("DeleteDeploy...........") // 删除策略 deletePolicy := v1.DeletePropagationForeground err := client.Delete(context.Background(), "deploy-nginx-demo", v1.DeleteOptions{PropagationPolicy: &deletePolicy}) if err != nil { klog.Errorf("delete deployment error, err:%v", err) } else { klog.Info("delete deployment success") } } func prompt() { fmt.Printf("-> Press Return key to continue.") scanner := bufio.NewScanner(os.Stdin) for scanner.Scan() { break } if err := scanner.Err(); err != nil { panic(err) } fmt.Println() }
