my-docs/Containerization-Orchestration/Kubernetes/workloads/08-Cronjobs.md

⏰ Kubernetes CronJobs

A CronJob in Kubernetes allows you to run jobs on a recurring schedule, similar to traditional UNIX cron jobs. Ideal for periodic tasks like backups, reports, or scheduled notifications.

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🔍 CronJob Commands

📄 List CronJobs in a Namespace

kubectl get cronjobs.batch -n <namespace>

❌ Delete a CronJob

kubectl delete cronjobs.batch -n <namespace> <cronjob-name>

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🧾 Example CronJob Manifest

This CronJob runs every minute and prints the date followed by "Kubernetes":

apiVersion: batch/v1
kind: CronJob
metadata:
  name: cronjob1
  namespace: ns
spec:
  schedule: "* * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
            - name: cronjob
              image: debian:bookworm
              command:
                - /bin/bash
                - -c
                - date; echo Kubernetes
          restartPolicy: Never

🛠 Fix: Changed JobTemplate to jobTemplate (YAML keys are case-sensitive). 🕐 The schedule field follows standard cron format: minute hour day-of-month month day-of-week. 🧠 Tip: Always test cron timing carefully to avoid unintentional frequent runs.