CronJob

CronJob

Create the new file with the command:

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: cronjob-hello
spec:
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: cron-hello
            image: r.deso.tech/library/alpine
            args:
            - /bin/sh
            - -c
            - date; echo Hello, Desotech Student!
          restartPolicy: OnFailure

For cronjob schedulation you can follow this link: https://crontab.guru/

Save and close the file, apply it.

kubectl apply -f cronjob-hello.yaml

cronjob.batch/cronjob-hello created

You can ensure the cronjob task is running with the command:

kubectl get cronjobs

NAME            SCHEDULE       SUSPEND   ACTIVE   LAST SCHEDULE   AGE
cronjob-hello   */10 * * * *   False     0        <none>          28s

How to watch for the cronjob? Let’s say you’ve deployed a container with an associated cronjob and you want to watch for it. To do that, you’d issue the command:

kubectl get jobs --watch

The output of that command will include a running list of every deployed job

NAME                       COMPLETIONS   DURATION   AGE
cronjob-hello-1607447700   0/1                      0s
cronjob-hello-1607447700   0/1           0s         0s
cronjob-hello-1607447700   1/1           4s         4s
cronjob-hello-1607447760   0/1                      0s
cronjob-hello-1607447760   0/1           0s         0s
cronjob-hello-1607447760   0/1           0s         1s
cronjob-hello-1607447760   1/1           3s         4s

To end that watch, use the ++ctrl++ + ++c++ combination. A new job will be started every minute.

kubectl get pod

NAME                             READY   STATUS      RESTARTS   AGE
cronjob-hello-1607447700-5mqsq   0/1     Completed   0          2m28s
cronjob-hello-1607447760-cnbjs   0/1     Completed   0          98s

Delete cronjob:

kubectl delete cronjob cronjob-hello

cronjob.batch "cronjob-hello" deleted

By deleting the cronjob you will also delete the completed pods.

kubectl get pod

No resources found in namespace01 namespace.