Error when creating pod

If the pod fails, the following two prompts will be displayed

[root@master ~]#kubectl get pods
NAME                         READY   STATUS             RESTARTS   AGE
net-test1-7c9c4b94d6-5mddl   1/1     Running            0          2m41s
net-test1-7c9c4b94d6-xk8jp   0/1     ImagePullBackOff   0          5s

[root@master ~]#kubectl get pods
NAME                         READY   STATUS         RESTARTS   AGE
net-test1-7c9c4b94d6-5mddl   1/1     Running        0          2m39s
net-test1-7c9c4b94d6-xk8jp   0/1     ErrImagePull   0          3s

Troubleshoot the cause of the problem

Check the log of pod and find that it is unable to download the image of pod.

[root@master ~]#kubectl logs net-test1-7c9c4b94d6-xk8jp 
Error from server (BadRequest): container "net-test1" in pod "net-test1-7c9c4b94d6-xk8jp" is waiting to start: trying and failing to pull image

Check which node the pod in question is on, and find that it is on node1 node.

[root@master ~]#kubectl get pods -o wide 
NAME                         READY   STATUS             RESTARTS   AGE   IP          NODE    NOMINATED NODE   R
net-test1-7c9c4b94d6-xk8jp   0/1     ImagePullBackOff   0          13s   10.10.1.7   node1   <none>           <
net-test1-7c9c4b94d6-5mddl   1/1     Running            0          14m   10.10.2.2   node2   <none>

Check whether the image can be downloaded manually in node1 node. It is found that the image cannot be downloaded.

[root@node1 ~]#docker pull alpine
Using default tag: latest
Error response from daemon: Get https://registry-1.docker.io/v2/: dial tcp: lookup registry-1.docker.io on 127.0.0.53:53: server misbehaving

Check whether node1 node can communicate with the network, and find that name resolution cannot be performed.

[root@node1 ~]#ping www.baidu.com
ping: www.baidu.com: Temporary failure in name resolution

Solve the problem

Modify the DNS of this node. The current host is ubuntu system.

[root@node1 ~]#vim /etc/systemd/resolved.conf 
#Uncomment this line and add DNS resolution address
[Resolve]
DNS=8.8.8.8

View on primary node

[root@master ~]#kubectl get pods
NAME                         READY   STATUS    RESTARTS   AGE
net-test1-7c9c4b94d6-5mddl   1/1     Running   0          5m44s
net-test1-7c9c4b94d6-xk8jp   1/1     Running   0          3m8s