How to ensure kubernetes cronjob does not restart on failure

Question

I have a cronjob that sends out emails to customers. It occasionally fails for various reasons. I do not want it to restart, but it still does.

I am running Kubernetes on GKE. To get it to stop, I have to delete the CronJob and then kill all the pods it creates manually.

This is bad, for obvious reasons.

apiVersion: batch/v1beta1 kind: CronJob metadata:   creationTimestamp: 2018-06-21T14:48:46Z   name: dailytasks   namespace: default   resourceVersion: "20390223"   selfLink: [redacted]   uid: [redacted] spec:   concurrencyPolicy: Forbid   failedJobsHistoryLimit: 1   jobTemplate:     metadata:       creationTimestamp: null     spec:       template:         metadata:           creationTimestamp: null         spec:           containers:           - command:             - kubernetes/daily_tasks.sh             env:             - name: DB_HOST               valueFrom:                 fieldRef:                   apiVersion: v1                   fieldPath: status.hostIP             envFrom:             - secretRef:                 name: my-secrets             image: [redacted]             imagePullPolicy: IfNotPresent             name: dailytasks             resources: {}             terminationMessagePath: /dev/termination-log             terminationMessagePolicy: File           dnsPolicy: ClusterFirst           restartPolicy: Never           schedulerName: default-scheduler           securityContext: {}           terminationGracePeriodSeconds: 30   schedule: 0 14 * * *   successfulJobsHistoryLimit: 3   suspend: true status:   active:   - apiVersion: batch     kind: Job     name: dailytasks-1533218400     namespace: default     resourceVersion: "20383182"     uid: [redacted]   lastScheduleTime: 2018-08-02T14:00:00Z 

Answer 1

It turns out that you have to set a backoffLimit: 0 in combination with restartPolicy: Never in combination with concurrencyPolicy: Forbid.

backoffLimit means the number of times it will retry before it is considered failed. The default is 6.

concurrencyPolicy set to Forbid means it will run 0 or 1 times, but not more.

restartPolicy set to Never means it won't restart on failure.

You need to do all 3 of these things, or your cronjob may run more than once.

spec:   concurrencyPolicy: Forbid   failedJobsHistoryLimit: 1   jobTemplate:     metadata:       creationTimestamp: null     spec:       [ADD THIS -->]backoffLimit: 0       template:        ... MORE STUFF ...