CKA-34-Kubernetes CronJobs

Schedule repeatable Kubernetes workloads with CronJobs and avoid common concurrency and missed-schedule pitfalls.

For CKA preparation, do not treat this as a definition to memorize. Treat it as a cluster behavior you should be able to inspect, configure, and verify under time pressure. This guide explains the operational purpose, the important moving parts, and a safe way to reason about it.

What you will learn: how cronjobs fits into workloads and scheduling, what to check first, and the mistakes that commonly lead to failed changes.

Scheduling recurring work without keeping a custom scheduler running

A CronJob creates Jobs on a schedule. It is useful for nightly reports, periodic cleanup, certificate checks, and other recurring tasks.

apiVersion: batch/v1
kind: CronJob
metadata:
  name: nightly-report
spec:
  schedule: "0 2 * * *"
  timeZone: "Asia/Kolkata"
  concurrencyPolicy: Forbid
  jobTemplate:
    spec:
      template:
        spec:
          restartPolicy: Never
          containers:
            - name: report
              image: example/report-generator:1.0

The five schedule fields represent minute, hour, day of month, month, and day of week. Here, the Job is scheduled for 2:00 a.m. in the specified time zone…