main.go

package main

import (
	"context"
	"flag"
	"fmt"
	"k8s.io/client-go/util/homedir"
	"path/filepath"

	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

	"k8s.io/client-go/kubernetes/scheme"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"
)

// 从namespace为kube-system中获取所有的pod并输出到屏幕

func main() {
	fmt.Println("Prepare config object.")
	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()

	// 加载k8s配置文件，生成Config对象
	config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
	if err != nil {
		panic(err)
	}

	// 参考path : /api/v1/namespaces/{namespace}/pods
	config.APIPath = "api"
	//  pod的group是空字符串
	config.GroupVersion = &corev1.SchemeGroupVersion
	// 设置编解码工具
	config.NegotiatedSerializer = scheme.Codecs

	fmt.Println("Init RESTClient.")

	// 定义RestClient，用于与k8s API server进行交互
	restClient, err := rest.RESTClientFor(config)
	if err != nil {
		panic(err)
	}

	fmt.Println("Get Pods in cluster.")

	// 获取pod列表。这里只会从namespace为"danny-xia"中获取指定的资源(pods)
	result := &corev1.PodList{}
	if err := restClient.
		Get().
		Namespace("danny-xia").
		Resource("pods").
		VersionedParams(&metav1.ListOptions{Limit: 500}, scheme.ParameterCodec).
		Do(context.TODO()).
		Into(result); err != nil {
		panic(err)
	}

	fmt.Println("Print all listed pods.")

	// 打印所有获取到的pods资源，输出到标准输出
	for _, d := range result.Items {
		fmt.Printf("NAMESPACE: %v NAME: %v \t STATUS: %v \n", d.Namespace, d.Name, d.Status.Phase)
	}
}