如何更新Kubernetes中的资源对象的Label

package main

import (
	"context"
	"flag"
	"fmt"
	"log"

	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"
)

func main() {
	// 解析命令行参数获取kubeconfig的路径
	kubeconfig := flag.String("kubeconfig", "", "path to the kubeconfig file")
	flag.Parse()

	// 使用kubeconfig文件创建一个kubernetes客户端
	config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
	if err != nil {
		log.Fatal(err)
	}
	clientset, err := kubernetes.NewForConfig(config)
	if err != nil {
		log.Fatal(err)
	}

	// 创建一个Pod的列表取得资源
	podList, err := clientset.CoreV1().Pods("default").List(context.TODO(), metav1.ListOptions{})
	if err != nil {
		log.Fatal(err)
	}

	// 遍历每个Pod并更新其Label
	for _, pod := range podList.Items {
		pod.Labels["app"] = "yifan-online-app"
		if _, err := clientset.CoreV1().Pods(pod.Namespace).Update(context.TODO(), &pod, metav1.UpdateOptions{}); err != nil {
			log.Fatal(err)
		}
		fmt.Printf("Updated Pod %s\n", pod.Name)
	}
}