Jobs and CronJobs for batch processing in Kubernetes - Mini Project: Build & Apply

Jobs and CronJobs for batch processing

📖 Scenario: You work in a company that needs to run tasks automatically in Kubernetes. Some tasks run once, and some run repeatedly on a schedule. You will create Kubernetes Job and CronJob resources to handle these batch tasks.

🎯 Goal: Learn how to create a Kubernetes Job to run a one-time batch task and a CronJob to run a task on a schedule.

📋 What You'll Learn

Create a Kubernetes Job YAML manifest with exact metadata and spec

Add a CronJob YAML manifest with a schedule and job template

Use the correct container image and command for the batch task

Print the created resource names to confirm creation

💡 Why This Matters

🌍 Real World

Companies use Kubernetes Jobs to run one-time batch tasks like data processing or backups. CronJobs run scheduled tasks like report generation or cleanup jobs automatically.

💼 Career

Knowing how to create and manage Jobs and CronJobs is essential for DevOps engineers and site reliability engineers to automate and maintain batch workloads in Kubernetes.

1

Create a Kubernetes Job manifest

Create a YAML manifest named job.yaml for a Kubernetes Job with these exact details: metadata name batch-job, spec template with a single container named batch-task using image busybox and command ["/bin/sh", "-c", "echo Hello from Job"]. The restart policy must be Never.

Kubernetes

# Write the YAML manifest for the Kubernetes Job here
# Your code here

Need a hint?

Remember to set kind to Job and use the exact container name and command.

2

Create a Kubernetes CronJob manifest

Create a YAML manifest named cronjob.yaml for a Kubernetes CronJob with these exact details: metadata name batch-cronjob, schedule "*/5 * * * *" (every 5 minutes), job template with a single container named cron-task using image busybox and command ["/bin/sh", "-c", "echo Hello from CronJob"]. The restart policy must be OnFailure.

Kubernetes

apiVersion: batch/v1
kind: Job
metadata:
  name: batch-job
spec:
  template:
    spec:
      containers:
      - name: batch-task
        image: busybox
        command: ["/bin/sh", "-c", "echo Hello from Job"]
      restartPolicy: Never

# Write the YAML manifest for the Kubernetes CronJob here
# Your code here

Need a hint?

Use kind: CronJob and set the schedule to run every 5 minutes exactly as shown.

3

Apply the Job and CronJob manifests

Write the exact kubectl commands to apply both job.yaml and cronjob.yaml files to the Kubernetes cluster.

Kubernetes

apiVersion: batch/v1
kind: Job
metadata:
  name: batch-job
spec:
  template:
    spec:
      containers:
      - name: batch-task
        image: busybox
        command: ["/bin/sh", "-c", "echo Hello from Job"]
      restartPolicy: Never
---
apiVersion: batch/v1
kind: CronJob
metadata:
  name: batch-cronjob
spec:
  schedule: "*/5 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: cron-task
            image: busybox
            command: ["/bin/sh", "-c", "echo Hello from CronJob"]
          restartPolicy: OnFailure

# Write the kubectl apply commands below
# Your code here

Need a hint?

Use kubectl apply -f with the exact file names.

4

Print the names of created Job and CronJob

Write the exact kubectl commands to list the names of Jobs and CronJobs in the current namespace.

Kubernetes

apiVersion: batch/v1
kind: Job
metadata:
  name: batch-job
spec:
  template:
    spec:
      containers:
      - name: batch-task
        image: busybox
        command: ["/bin/sh", "-c", "echo Hello from Job"]
      restartPolicy: Never
---
apiVersion: batch/v1
kind: CronJob
metadata:
  name: batch-cronjob
spec:
  schedule: "*/5 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: cron-task
            image: busybox
            command: ["/bin/sh", "-c", "echo Hello from CronJob"]
          restartPolicy: OnFailure

kubectl apply -f job.yaml
kubectl apply -f cronjob.yaml

# Write the kubectl commands to list Job and CronJob names
# Your code here

Need a hint?

Use kubectl get jobs and kubectl get cronjobs with custom columns to show only names.