How to debug ImagePullBackOff

Question

All of a sudden  I cannot deploy some images which could be deployed before  I got the following pod status    root webdev2 origin   oc get pods  NAME                      READY     STATUS             RESTARTS   AGE  arix-3-yjq9w              0 1       ImagePullBackOff   0          10m  docker-registry-2-vqstm   1 1       Running            0          2d  router-1-kvjxq            1 1       Running            0          2d    The application just won t start  The pod is not trying to run the container  From the Event page  I have got Back-off pulling image  172 30 84 25 5000 default arix sha256 d326  I have verified that I can pull the image with the tag with docker pull   I have also checked the log of the last container  It was closed for some reason  I think the pod should at least try to restart it   I have run out of ideas to debug the issues  What can I check more

User · Answer

Have you tried to edit to see what s wrong  I had the wrong image location   kubectl edit pods arix-3-yjq9w   or even delete your pod   kubectl delete arix-3-yjq9w

User · Answer

You can use the  describe pod  syntax  For OpenShift use   oc describe pod  lt pod-id gt      For vanilla Kubernetes   kubectl describe pod  lt pod-id gt      Examine the events of the output  In my case it shows Back-off pulling image coredns coredns latest  In this case the image coredns coredns latest can not be pulled from the Internet   Events    FirstSeen LastSeen    Count   From                SubObjectPath           Type        Reason      Message   --------- --------    -----   ----                -------------           --------    ------      -------   5m        5m      1    default-scheduler                          Normal      Scheduled   Successfully assigned coredns-4224169331-9nhxj to 192 168 122 190   5m        1m      4    kubelet 192 168 122 190    spec containers coredns     Normal      Pulling     pulling image  coredns coredns latest    4m        26s     4    kubelet 192 168 122 190    spec containers coredns     Warning     Failed      Failed to pull image  coredns coredns latest   Network timed out while trying to connect to https   index docker io v1 repositories coredns coredns images  You may want to check your internet connection or if you are behind a proxy    4m        26s     4    kubelet 192 168 122 190                    Warning     FailedSync  Error syncing pod  skipping  failed to  StartContainer  for  coredns  with ErrImagePull   Network timed out while trying to connect to https   index docker io v1 repositories coredns coredns images  You may want to check your Internet connection or if you are behind a proxy      4m    2s  7    kubelet 192 168 122 190    spec containers coredns     Normal  BackOff     Back-off pulling image  coredns coredns latest    4m    2s  7    kubelet 192 168 122 190                    Warning FailedSync  Error syncing pod  skipping  failed to  StartContainer  for  coredns  with ImagePullBackOff   Back-off pulling image   coredns coredns latest      Additional debuging steps   try to pull the docker image and tag manually on your computer  Identify the node by doing a  kubectl oc get pods -o wide   ssh into the node  if you can  that can not pull the docker image  check that the node can resolve the DNS of the docker registry by performing a ping   try to pull the docker image manually on the node If you are using a private registry  check that your secret exists and the secret is correct  Your secret should also be in the same namespace  Thanks swenzel Some registries have firewalls that limit ip address access  The firewall may block the pull Some CIs create deployments with temporary docker secrets  So the secret expires after a few days  You are asking for production failures

User · Answer

I ran into this issue on GKE and the reason was no credentials for docker  Running this resolved it  gcloud auth configure-docker

User · Answer

On GKE  if the pod is dead  it s best to check for the events  It will show in more detail what the error is about  In my case  I had   Failed to pull image  quot gcr io project imagename sha256 c8e91af54fc17faa1c49e2a05def5cbabf8f0a67fc558eb6cbca138061a8400a quot    rpc error  code   Unknown desc   error pulling image configuration  unknown blob  It turned out the image was damaged somehow  After repushing it and deploying with the new hash  it worked again

User · Answer

I forgot to push the image tagged 1 0 8 to the ECR  AWS images hub     If you are using Helm and upgrade by      helm upgrade minta-user   src services user helm-chart   make sure that image tag inside values yaml is pushed  to ECR or Docker Hub  etc  for example   this is my helm-chart values yaml   replicaCount  1  image     repository dkr ecr us-east-1 amazonaws com minta-user    tag  1 0 8   you need to make sure that the image 1 0 8 is pushed

User · Answer

I faced the similar situation and it turned out that with the actualisation of Docker Desktop I was signed out and after I signed back in all works fine again

User · Answer

I was facing the similar problem  but  instead of one all of my pods were not ready and displaying Ready status 0 1 Something like  I tried a lot of things but at last i found that the context was not correctly set  Please use following command and ensure you are in correct context kubectl config get-contexts

User · Answer

Run docker login  Push the image to docker hub  Re-create pod  This solved the problem for me  Hope it helps

[kubernetes] How to debug "ImagePullBackOff"?

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