A job in Kubernetes is a supervisor for pods carrying out batch processes, that is, a process that runs for a certain time to completion, for example a calculation or a backup operation.

Let’s create a job called countdown that supervises a pod counting from 9 down to 1:

$kubectl apply -f https://raw.githubusercontent.com/openshift-evangelists/kbe/master/specs/jobs/job.yaml  You can see the job and the pod it looks after like so: $ kubectl get jobs
NAME                      DESIRED   SUCCESSFUL   AGE
countdown                 1         1            5s

$kubectl get pods NAME READY STATUS RESTARTS AGE countdown-qkjx8 0/1 Completed 0 2m17s  To learn more about the status of the job, do: $ kubectl describe jobs/countdown
Name:           countdown
Namespace:      default
Selector:       controller-uid=4960c8be-6a3f-11ea-84fd-0242ac11002a
Labels:         controller-uid=4960c8be-6a3f-11ea-84fd-0242ac11002a
job-name=countdown
Annotations:    kubectl.kubernetes.io/last-applied-configuration:
Parallelism:    1
Completions:    1
Start Time:     Fri, 20 Mar 2020 00:11:03 +0000
Completed At:   Fri, 20 Mar 2020 00:11:12 +0000
Duration:       9s
Pods Statuses:  0 Running / 1 Succeeded / 0 Failed
Pod Template:
Labels:  controller-uid=4960c8be-6a3f-11ea-84fd-0242ac11002a
job-name=countdown
Containers:
counter:
Image:      centos:7
Port:       <none>
Host Port:  <none>
Command:
bin/bash
-c
for i in 9 8 7 6 5 4 3 2 1 ; do echo $i ; done Environment: <none> Mounts: <none> Volumes: <none> Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal SuccessfulCreate 3m18s job-controller Created pod: countdown-qkjx8  And to see the output of the job via the pod it supervised, execute: kubectl logs countdown-qkjx8 9 8 7 6 5 4 3 2 1  To clean up, use the delete verb on the job object which will remove all the supervised pods: $ kubectl delete job countdown
job "countdown" deleted


Note that there are also more advanced ways to use jobs, for example, by utilizing a work queue or scheduling the execution at a certain time via cron jobs.