Kubernetes - how to run job only once

问题:

I have a job definition based on example from kubernetes website.

apiVersion: batch/v1
kind: Job
metadata:
  name: pi-with-timeout-6
spec:
  activeDeadlineSeconds: 30
  completions: 1
  paralleism: 1
  template:
    metadata:
      name: pi
    spec:
      containers:
      - name: pi
        image: perl
        command: ["exit", "1"]
      restartPolicy: Never

I would like run this job once and not restart if fails. With comand exit 1 kubernetes trying to run new pod to get exit 0 code until reach activeDeadlineSeconds timeout. How can avoid that? I would like run build commands in kubernetes to check compilation and if compilation fails I'll get exit code different than 0. I don't want run compilation again.

Is it possible? How?

回答1:

If you want a one-try command runner, you probably should create bare pod, because the job will try to execute the command until it's successful or the active deadline is met.

Just create the pod from your template:

apiVersion: v1
kind: Pod
metadata:
  name: pi
spec:
  containers:
  - name: pi
    image: perl
    command: ["exit", "1"]
  restartPolicy: Never

回答2:

By now this is possible by setting backoffLimit: 0 which tells the controller to do 0 retries. default is 6

回答3:

Sadly there is currently no way to prevent the job controller to just respawn new pods when they fail, but the kubernetes community is working on a solution, see:

"Backoff policy and failed pod limit" https://github.com/kubernetes/community/pull/583