.. _cron_job:

Cron Job
--------

A `Cron Job <https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/>`_ creates jobs that run on a specific
timed interval.  You'll want to create a YAML file describing the cron job::

    apiVersion: batch/v1beta1
    kind: CronJob
    metadata:
      name: xx-ecr-login-cron
    spec:
      schedule: "* */8 * * *"
      successfulJobsHistoryLimit: 2
      failedJobsHistoryLimit: 2
      concurrencyPolicy: Forbid
      jobTemplate:
        spec:
          backoffLimit: 4
          template:
            spec:
              serviceAccountName: ecr-cron-sa
              terminationGracePeriodSeconds: 0
              restartPolicy: Never
              containers:
              - name: ecr-login
                imagePullPolicy: Always
                image: simoncomputing/ecr-login:1.0
                command:
                  - "/login.sh"
                env:
                  - name: ECR_URL
                    valueFrom:
                      secretKeyRef:
                        name: aws-info
                        key: ecr-url
                  - name: AWS_ACCOUNT
                    valueFrom:
                      secretKeyRef:
                        name: aws-info
                        key: aws-account
                  - name: AWS_REGION
                    valueFrom:
                      secretKeyRef:
                        name: aws-info
                        key: region
                  - name: NAMESPACES
                    value: "default"

This is an example of running a cron job that will create a container to run from a predefined
Docker image.

The **schedule** is in a standard `Cron <https://en.wikipedia.org/wiki/Cron>`_ format.

Note that you wil also want to run it with a service account that you've created with the appropriate
permissions.


.. autofunction:: k9.batch.list_cron_jobs
.. autofunction:: k9.batch.create_cron_job
.. autofunction:: k9.batch.delete_cron_job
.. autofunction:: k9.batch.get_cron_job
.. autofunction:: k9.batch.cron_job_exists