一个拼写错误引发的问题：Failed to pull image "nignx": rpc error: code = Unknown desc = Error response from daemon: pull access denied for nignx, repository does not exist or may require 'docker login'

问题

在引入阿里镜像加速器后，手动命令行部署nginx，发现pod的status为ImagePullBackOff

排查思路

1.使用kubectl describe pod web-64d985c689-49d4b检查pod的一些信息，发现最关键的一句是：Failed to pull image "nignx": rpc error: code = Unknown desc = Error response from daemon: pull access denied for nignx, repository does not exist or may require 'docker login'，原来是nginx拼写成了nignx

[root@k8s-master ~]# kubectl describe pod web-64d985c689-49d4b
Name:         web-64d985c689-49d4b
Namespace:    default
Priority:     0
Node:         k8s-node1/192.168.1.166
Start Time:   Sat, 15 Oct 2022 16:03:42 +0800
Labels:       app=web
              pod-template-hash=64d985c689
Annotations:  <none>
Status:       Pending
IP:           10.244.2.6
IPs:
  IP:           10.244.2.6
Controlled By:  ReplicaSet/web-64d985c689
Containers:
  nignx:
    Container ID:   
    Image:          nignx
    Image ID:       
    Port:           <none>
    Host Port:      <none>
    State:          Waiting
      Reason:       ImagePullBackOff
    Ready:          False
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-597tl (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             False 
  ContainersReady   False 
  PodScheduled      True 
Volumes:
  default-token-597tl:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-597tl
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type     Reason     Age                    From                Message
  ----     ------     ----                   ----                -------
  Normal   Scheduled  5m54s                  default-scheduler   Successfully assigned default/web-64d985c689-49d4b to k8s-node1
  Normal   Pulling    3m6s (x4 over 5m53s)   kubelet, k8s-node1  Pulling image "nignx"
  Warning  Failed     2m45s (x4 over 5m21s)  kubelet, k8s-node1  Failed to pull image "nignx": rpc error: code = Unknown desc = Error response from daemon: pull access denied for nignx, repository does not exist or may require 'docker login'
  Warning  Failed     2m45s (x4 over 5m21s)  kubelet, k8s-node1  Error: ErrImagePull
  Normal   BackOff    2m32s (x6 over 5m21s)  kubelet, k8s-node1  Back-off pulling image "nignx"
  Warning  Failed     51s (x13 over 5m21s)   kubelet, k8s-node1  Error: ImagePullBackOff

2.依次删除deployment、pod、service, 当删除了deployment的时候，pod也会自动被删除

root@k8s-master ~]# kubectl delete deployment web -n default
deployment.apps "web" deleted
[root@k8s-master ~]# kubectl get deployment -n default
No resources found in default namespace.
[root@k8s-master ~]# kubectl get pod -n default
No resources found in default namespace.
[root@k8s-master ~]# kubectl get pods
No resources found in default namespace.
[root@k8s-master ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP        2d15h
web1         NodePort    10.102.149.13   <none>        80:32398/TCP   14m
[root@k8s-master ~]# kubectl delete svc web1 -n default
service "web1" deleted

重新部署

先删除上次的yaml文件，再按照顺序依次部署，最后发现pod的状态是Running

[root@k8s-master ~]# ls
anaconda-ks.cfg  web1.yaml  web.yaml
[root@k8s-master ~]# rm -rf web*
[root@k8s-master ~]# ls
anaconda-ks.cfg
[root@k8s-master ~]# kubectl create deployment web --image=nginx --dry-run -o yaml > web.yaml
W1015 16:21:34.834821   55655 helpers.go:535] --dry-run is deprecated and can be replaced with --dry-run=client.
[root@k8s-master ~]# ls
anaconda-ks.cfg  web.yaml
[root@k8s-master ~]# kubectl apply -f web.yaml 
deployment.apps/web created
[root@k8s-master ~]# kubectl get deployment
NAME   READY   UP-TO-DATE   AVAILABLE   AGE
web    0/1     1            0           15s
[root@k8s-master ~]# kubectl expose deployment web --port=80 --type=NodePort --target-port=80 --name=web1 -o yaml > web1.yaml
[root@k8s-master ~]# ls
anaconda-ks.cfg  web1.yaml  web.yaml
[root@k8s-master ~]# kubectl get deployment
NAME   READY   UP-TO-DATE   AVAILABLE   AGE
web    1/1     1            1           84s
[root@k8s-master ~]# kubectl get pods
NAME                   READY   STATUS    RESTARTS   AGE
web-5dcb957ccc-hmx7h   1/1     Running   0          91s
[root@k8s-master ~]# kubectl apply -f web1.yaml 
Warning: kubectl apply should be used on resource created by either kubectl create --save-config or kubectl apply
service/web1 configured
[root@k8s-master ~]# kubectl get pods,svc
NAME                       READY   STATUS    RESTARTS   AGE
pod/web-5dcb957ccc-hmx7h   1/1     Running   0          112s

NAME                 TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
service/kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP        2d15h
service/web1         NodePort    10.104.228.101   <none>        80:31425/TCP   35s