Kubernetes拉取映像失败：授权失败

我创建了一个Docker镜像，并将其推送到了一个私有的Docker Hub存储库。使用以下清单文件，我尝试创建一个新的Pod：

apiVersion: v1
kind: Pod
metadata:
  name: web-app-pod
  labels:
    app: web
spec:
  containers:
    - name: web-app-container
      image: {docker_hub_username}/{repository_name}:tag
      ports:
        - containerPort: 8080

要创建新的Pod，我只需尝试以下操作：

kubectl apply -f pod.yml
kubectl get pods --watch

其输出如下：

NAME          READY   STATUS             RESTARTS   AGE
web-app-pod   0/1     ImagePullBackOff   0          7m35s

这表明Kubernetes无法从Docker Hub中提取图像。为了获得更详细的报告，我尝试了以下方法：

kubectl describe po web-app-pod

Events:
  Type     Reason     Age                From               Message
  ----     ------     ----               ----               -------
  Normal   Scheduled  22s                default-scheduler  Successfully assigned default/web-app-pod to lke91166-138019-63e1c8b4d01b
  Normal   BackOff    20s (x2 over 21s)  kubelet            Back-off pulling image "{docker_hub_username}/{repository_name}:tag"
  Warning  Failed     20s (x2 over 21s)  kubelet            Error: ImagePullBackOff
  Normal   Pulling    7s (x2 over 22s)   kubelet            Pulling image "{docker_hub_username}/{repository_name}:tag"
  Warning  Failed     7s (x2 over 22s)   kubelet            Failed to pull image "{docker_hub_username}/{repository_name}:tag": rpc error: code = Unknown desc = failed to pull and unpack image "docker.io/{docker_hub_username}/{repository_name}:tag": failed to resolve reference "docker.io/{docker_hub_username}/{repository_name}:tag": pull access denied, repository does not exist or may require authorization: server message: insufficient_scope: authorization failed
  Warning  Failed     7s (x2 over 22s)   kubelet            Error: ErrImagePull