Wait for kubernetes job to complete on either failure/success using command line

问题

What is the best way to wait for kubernetes job to be complete? I noticed a lot of suggestions to use:

kubectl wait --for=condition=complete job/myjob

but i think that only works if the job is successful. if it fails, i have to do something like:

kubectl wait --for=condition=failure job/myjob

is there a way to wait for both conditions using wait? if not, what is the best way to wait for a job to either succeed or fail?

回答1:

kubectl wait --for=condition=<condition name is waiting for a specific condition, so afaik it can not specify multiple conditions at the moment.

My workaround is using oc get --wait, --wait is closed the command if the target resource is updated. I will monitor status section of the job using oc get --wait until status is updated. Update of status section is meaning the Job is complete with some status conditions.

If the job complete successfully, then status.conditions.type is updated immediately as Complete. But if the job is failed then the job pod will be restarted automatically regardless restartPolicy is OnFailure or Never. But we can deem the job is Failed status if not to updated as Complete after first update.

Look the my test evidence as follows.

• Job yaml for testing successful complete

    # vim job.yml
    apiVersion: batch/v1
    kind: Job
    metadata:
      name: pi
    spec:
      parallelism: 1
      completions: 1
      template:
        metadata:
          name: pi
        spec:
          containers:
          - name: pi
            image: perl
            command: ["perl",  "-wle", "exit 0"]
          restartPolicy: Never

• It will show you Complete if it complete the job successfully.

    # oc create -f job.yml &&
      oc get job/pi -o=jsonpath='{.status}' -w &&
      oc get job/pi -o=jsonpath='{.status.conditions[*].type}' | grep -i -E 'failed|complete' || echo "Failed" 

    job.batch/pi created
    map[startTime:2019-03-09T12:30:16Z active:1]Complete

• Job yaml for testing failed complete

    # vim job.yml
    apiVersion: batch/v1
    kind: Job
    metadata:
      name: pi
    spec:
      parallelism: 1
      completions: 1
      template:
        metadata:
          name: pi
        spec:
          containers:
          - name: pi
            image: perl
            command: ["perl",  "-wle", "exit 1"]
          restartPolicy: Never

• It will show you Failed if the first job update is not Complete. Test if after delete the existing job resource.

    # oc delete job pi
    job.batch "pi" deleted

    # oc create -f job.yml &&
      oc get job/pi -o=jsonpath='{.status}' -w &&
      oc get job/pi -o=jsonpath='{.status.conditions[*].type}' | grep -i -E 'failed|complete' || echo "Failed" 

    job.batch/pi created
    map[active:1 startTime:2019-03-09T12:31:05Z]Failed

I hope it help you. :)

来源：https://stackoverflow.com/questions/55073453/wait-for-kubernetes-job-to-complete-on-either-failure-success-using-command-line