环境准备

（我没环境，看个热闹）

通过kind创建多节点的k8s集群: 3个master节点 + 3个worker节点
tip：kind简介
安不上！！！

  1. # 先安装kind
  2. go get sigs.k8s.io/kind@v0.5.1
  4. # 创建集群
  5. kind create cluster --config=init_cluster.yaml

init_cluster.yaml

  1. # a cluster with 3 control-plane nodes and 3 workers
  2. kind: Cluster
  3. apiVersion: kind.x-k8s.io/v1alpha4
  4. nodes:
  5. - role: control-plane
  6. - role: control-plane
  7. - role: control-plane
  8. - role: worker
  9. - role: worker
  10. - role: worker

RestClient使用例子

这段代码的作用：从namespace为kube-system中获取所有的pod并输出到屏幕
main.go

  1. package main
  3. import (
  4.         "context"
  5.         "fmt"
  7.         corev1 "k8s.io/api/core/v1"
  8.         metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
  10.         "k8s.io/client-go/kubernetes/scheme"
  11.         "k8s.io/client-go/rest"
  12.         "k8s.io/client-go/tools/clientcmd"
  13. )
  15. func main() {
  16.         fmt.Println("Prepare config object.")
  18.         // 加载k8s配置文件，生成Config对象
  19.         config, err := clientcmd.BuildConfigFromFlags("", "/root/.kube/config")
  20.         if err != nil {
  21.                 panic(err)
  22.         }
  24.         config.APIPath = "api"
  25.         config.GroupVersion = &corev1.SchemeGroupVersion
  26.         config.NegotiatedSerializer = scheme.Codecs
  28.         fmt.Println("Init RESTClient.")
  30.         // 定义RestClient，用于与k8s API server进行交互
  31.         restClient, err := rest.RESTClientFor(config)
  32.         if err != nil {
  33.                 panic(err)
  34.         }
  36.         fmt.Println("Get Pods in cluster.")
  38.         // 获取pod列表。这里只会从namespace为"kube-system"中获取指定的资源(pods)
  39.         result := &corev1.PodList{}
  40.         if err := restClient.
  41.                 Get().
  42.                 Namespace("kube-system").
  43.                 Resource("pods").
  44.                 VersionedParams(&metav1.ListOptions{Limit: 500}, scheme.ParameterCodec).
  45.                 Do(context.TODO()).
  46.                 Into(result); err != nil {
  47.                 panic(err)
  48.         }
  50.         fmt.Println("Print all listed pods.")
  52.         // 打印所有获取到的pods资源，输出到标准输出
  53.         for _, d := range result.Items {
  54.                 fmt.Printf("NAMESPACE: %v NAME: %v \t STATUS: %v \n", d.Namespace, d.Name, d.Status.Phase)
  55.         }
  56. }

go.mod

  1. module main
  3. go 1.15
  5. require (
  6.         github.com/go-logr/logr v0.2.1 // indirect
  7.         github.com/google/gofuzz v1.2.0 // indirect
  8.         github.com/imdario/mergo v0.3.11 // indirect
  9.         golang.org/x/crypto v0.0.0-20201002170205-7f63de1d35b0 // indirect
  10.         golang.org/x/net v0.0.0-20201010224723-4f7140c49acb // indirect
  11.         golang.org/x/oauth2 v0.0.0-20200902213428-5d25da1a8d43 // indirect
  12.         golang.org/x/sys v0.0.0-20201009025420-dfb3f7c4e634 // indirect
  13.         golang.org/x/time v0.0.0-20200630173020-3af7569d3a1e // indirect
  14.         k8s.io/api v0.19.2
  15.         k8s.io/apimachinery v0.19.2
  16.         //k8s.io/client-go v11.0.0+incompatible
  17.         //      k8s.io/client-go v11.0.0+incompatible
  18.         k8s.io/klog v1.0.0 // indirect
  19.         k8s.io/klog/v2 v2.3.0 // indirect
  20.         k8s.io/utils v0.0.0-20201005171033-6301aaf42dc7 // indirect
  21. )
  23. require k8s.io/client-go v0.19.2

输出结果

  1. [root@xxx-wsl ~/client-go-example] go run main.go
  2. Prepare config object.
  3. Init RESTClient.
  4. Get Pods in cluster.
  5. Print all listed pods.
  6. NAMESPACE: kube-system NAME: coredns-f9fd979d6-rhzfd     STATUS: Running
  7. NAMESPACE: kube-system NAME: coredns-f9fd979d6-whrj2     STATUS: Running
  8. NAMESPACE: kube-system NAME: etcd-kind-control-plane     STATUS: Running
  9. NAMESPACE: kube-system NAME: etcd-kind-control-plane2    STATUS: Running
  10. NAMESPACE: kube-system NAME: etcd-kind-control-plane3    STATUS: Running
  11. NAMESPACE: kube-system NAME: kindnet-bpsfl       STATUS: Running
  12. NAMESPACE: kube-system NAME: kindnet-ks6zv       STATUS: Running
  13. NAMESPACE: kube-system NAME: kindnet-pm6zl       STATUS: Running
  14. NAMESPACE: kube-system NAME: kindnet-qfhqt       STATUS: Running
  15. NAMESPACE: kube-system NAME: kindnet-s7qqn       STATUS: Running
  16. NAMESPACE: kube-system NAME: kindnet-trk5l       STATUS: Running
  17. NAMESPACE: kube-system NAME: kube-apiserver-kind-control-plane   STATUS: Running
  18. NAMESPACE: kube-system NAME: kube-apiserver-kind-control-plane2          STATUS: Running
  19. NAMESPACE: kube-system NAME: kube-apiserver-kind-control-plane3          STATUS: Running
  20. NAMESPACE: kube-system NAME: kube-controller-manager-kind-control-plane          STATUS: Running
  21. NAMESPACE: kube-system NAME: kube-controller-manager-kind-control-plane2         STATUS: Running
  22. NAMESPACE: kube-system NAME: kube-controller-manager-kind-control-plane3         STATUS: Running
  23. NAMESPACE: kube-system NAME: kube-proxy-7gz67    STATUS: Running
  24. NAMESPACE: kube-system NAME: kube-proxy-bvbkk    STATUS: Running
  25. NAMESPACE: kube-system NAME: kube-proxy-clf72    STATUS: Running
  26. NAMESPACE: kube-system NAME: kube-proxy-d8zpb    STATUS: Running
  27. NAMESPACE: kube-system NAME: kube-proxy-dsmsj    STATUS: Running
  28. NAMESPACE: kube-system NAME: kube-proxy-fplkk    STATUS: Running
  29. NAMESPACE: kube-system NAME: kube-scheduler-kind-control-plane   STATUS: Running
  30. NAMESPACE: kube-system NAME: kube-scheduler-kind-control-plane2          STATUS: Running
  31. NAMESPACE: kube-system NAME: kube-scheduler-kind-control-plane3          STATUS: Running