This is meant to serve as an example for running cron jobs.
deployment.yaml will run cron jobs inside of a pod on Kubernetes. Example image from https://github.com/bambash/docker-cron. Its fine for simple things, but not recommended to run crons as root.
cronjob.yaml will create a CronJob resource in Kubernetes. Documentation: https://cloud.google.com/kubernetes-engine/docs/how-to/cronjobs
expanding on the CronJob resource, I pushed an example helm chart here: https://github.com/bambash/helm-cronjobs
To use deployment.yaml, add your cronfiles to Cronjobs and create a ConfigMap:
# kubectl create configmap cronfiles --from-file Cronfiles/
configmap "cronfiles" created
After the ConfigMap exists, create the deployment:
# kubectl apply -f deployment.yaml
deployment "cron" created
After your cron executes, you should see the output:
# kubectl logs -f cron-7cf5bd99b7-bcq8g
Thu Mar 29 04:42:02 UTC 2018 hello from kubernetes
Thu Mar 29 04:43:01 UTC 2018 hello from kubernetes
Thu Mar 29 04:44:01 UTC 2018 hello from kubernetes
To use cronjob.yaml, create the resource:
kubectl apply -f cronjob.yaml
List your current cronjobs:
# kubectl get cronjob
NAME SCHEDULE SUSPEND ACTIVE LAST SCHEDULE AGE
example-cronjob * * * * * False 0 40s 6m
List jobs spawned:
# kubectl get jobs
NAME DESIRED SUCCESSFUL AGE
example-cronjob-1522301640 1 1 2m
example-cronjob-1522301700 1 1 1m
example-cronjob-1522301760 1 1 26s
List finished job pods:
# kubectl get pods -a
NAME READY STATUS RESTARTS AGE
example-cronjob-1522301700-4p68q 0/1 Completed 0 3m
example-cronjob-1522301760-x4nwd 0/1 Completed 0 2m
example-cronjob-1522301820-5qtcs 0/1 Completed 0 1m
Get logs from finished job pod:
# kubectl logs example-cronjob-1522301820-5qtcs
i am a cronjob