Kubernetes jobs execute one time task. A Job creates one or more Pods and will continue to retry execution of the Pods until a specified number of them successfully terminate.
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Running an example Job
apiVersion: batch/v1
kind: Job
metadata:
name: query-k8s-apps
spec:
ttlSecondsAfterFinished: 100
template:
spec:
containers:
- args:
- -c
- /apps/query-k8s-apps -n dev,qa
command:
- /bin/sh
- name: query-k8s-apps
image: ektowett/query-k8s-apps:latest
env:
- name: CONTEXTS
value: cloud_okteto_com
- name: DB_PASSWORD
valueFrom:
secretKeyRef:
key: password
name: rails-mariadb-secret
restartPolicy: Never
backoffLimit: 4
Execute
kubectl apply -f job.yaml
Output job as yaml:
kubectl get job myjob -o yaml
# Job termination and cleanup
When a Job completes, no more Pods are created, but the Pods are not deleted either. Keeping them around allows you to still view the logs of completed pods to check for errors, warnings, or other diagnostic output. The job object also remains after it is completed so that you can view its status. It is up to the user to delete old jobs after noting their status. Delete the job with kubectl (e.g. kubectl delete jobs/pi or kubectl delete -f ./job.yaml). When you delete the job using kubectl, all the pods it created are deleted too.
# CronJob
A CronJob creates Jobs on a repeating schedule. One CronJob object is like one line of a crontab (cron table) file. It runs a job periodically on a given schedule, written in Cron format.
Example
apiVersion: batch/v1
kind: CronJob
metadata:
name: query-k8s-apps
spec:
schedule: "*/5 * * * *"
jobTemplate:
spec:
template:
spec:
containers:
- name: query-k8s-apps
image: ${dockerRegistry}:${env.BRANCH_NAME}-${COMMIT_ID.take(10)}
imagePullPolicy: IfNotPresent
env:
- name: CONTEXTS
value: cloud_okteto_com
- name: APP_URL
value: http://iserve.kip0127.cloud.okteto.net/api/v1/k8s-versions
- name: NAMESPACES
value: kip0127
restartPolicy: OnFailure
Get a list of cronjobs present:
kubectl get cronjobs