OpenShift Container Platform

Create cron jobs

Create a cron job to schedule recurring tasks using cron expressions, configuring time zone, concurrency policies, history limits, and suspension behavior.

You create a cron job in OpenShift Container Platform by creating a job object.

You can also create and launch a cron job from a single command using oc create cronjob. The following command creates and launches a cron job similar to the one specified in the following example:

$ oc create cronjob pi --image=perl --schedule='*/1 * * * *' -- perl -Mbignum=bpi -wle 'print bpi(2000)'

With oc create cronjob, the --schedule option accepts schedules in cron format.

Procedure

Create a YAML file similar to the following:
```
apiVersion: batch/v1
kind: CronJob
metadata:
  name: pi
spec:
  schedule: "*/1 * * * *"
  timeZone: Etc/UTC
  concurrencyPolicy: "Replace"
  startingDeadlineSeconds: 200
  suspend: true
  successfulJobsHistoryLimit: 3
  failedJobsHistoryLimit: 1
  jobTemplate:
    spec:
      template:
        metadata:
          labels:
            parent: "cronjobpi"
        spec:
          containers:
          - name: pi
            image: perl
            command: ["perl",  "-Mbignum=bpi", "-wle", "print bpi(2000)"]
          restartPolicy: OnFailure
#...
```
where:

spec.schedule

Specifies the schedule for the job in cron format. In this example, the job will run every minute.

spec.timeZone

Specifies a time zone for the schedule. See List of tz database time zones for valid options. If not specified, the Kubernetes controller manager interprets the schedule relative to its local time zone. This value is optional.

spec.concurrencyPolicy

Specifies how to treat concurrent jobs within a cron job. Only one of the following concurrent policies may be specified. If not specified, this defaults to allowing concurrent executions: Allow (allows cron jobs to run concurrently), Forbid (forbids concurrent runs, skipping the next run if the previous has not finished yet), or Replace (cancels the currently running job and replaces it with a new one). This value is optional.

spec.startingDeadlineSeconds

Specifies a deadline (in seconds) for starting the job if it misses its scheduled time for any reason. Missed jobs executions will be counted as failed ones. If not specified, there is no deadline. This value is optional.

spec.suspend

Specifies a flag allowing the suspension of a cron job. If set to true, all subsequent executions will be suspended. This value is optional.

spec.successfulJobsHistoryLimit

Specifies the number of successful finished jobs to retain (defaults to 3).

spec.failedJobsHistoryLimit

Specifies the number of failed finished jobs to retain (defaults to 1).

spec.jobTemplate

Specifies the job template. This is similar to the job example.

spec.jobTemplate.spec.template.metadata.labels

Specifies labels for jobs spawned by this cron job.

spec.jobTemplate.spec.template.spec.restartPolicy

Specifies the restart policy of the pod. This does not apply to the job controller.
Create the cron job:
```
$ oc create -f <file-name>.yaml
```