How to execute script shell in Kubernetes cronjob

Question

I would like to run a shell script inside the Kubernetes using CronJob, here is my CronJon.yaml file :

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: hello
spec:
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: hello
            image: busybox
            imagePullPolicy: IfNotPresent
            command:
            - /bin/sh
            - -c
            - /home/admin_/test.sh
          restartPolicy: OnFailure

CronJob has been created ( kubectl apply -f CronJob.yaml ) when I get the list of cronjob I can see the cron job ( kubectl get cj ) and when I run "kubectl get pods" I can see the pod is being created, but pod crashes. Can anyone help me to learn how I can create a CronJob inside the Kubernetes please ?

Answer 1

As correctly pointed out in the comments, you need to provide the script file in order to execute it via your CronJob. You can do that by mounting the file within a volume. For example, your CronJob could look like this:

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: hello
spec:
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: hello
            image: busybox
            imagePullPolicy: IfNotPresent
            command:
            - /bin/sh
            - -c
            - /myscript/test.sh
            volumeMounts:
            - name: script-dir
              mountPath: /myscript
          restartPolicy: OnFailure
          volumes:
          - name: script-dir
            hostPath:
              path: /path/to/my/script/dir
              type: Directory

Example above shows how to use the hostPath type of volume in order to mount the script file.