title: Setting concurrency Kubernetes Cronjob
body: <p>This is a pretty basic question that I cannot seem to find an answer to, but I cannot figure out how to set the concurrencyPolicy in a cronjob. I have tried variations of my current file config:</p>
  
  <pre><code>apiVersion: batch/v1beta1
  kind: CronJob
  metadata:
    name: job-newspaper
  spec:
    schedule: "* */3 * * *"
    jobTemplate:
      spec:
        template:
          spec:
            containers:
             - name: job-newspaper
              image: bdsdev.azurecr.io/job-newspaper:latest
              imagePullPolicy: Always
              resources:
                limits:
                  cpu: "2048m"
                  memory: "10G"
                requests:
                  cpu: "512m"
                  memory: "2G"
              command: ["spark-submit","/app/newspaper_job.py"]
            restartPolicy: OnFailure
            concurrencyPolicy: Forbid
  </code></pre>
  
  <p>When I run <code>kubectl create -f ./job.yaml</code> I get the following error:</p>
  
  <pre><code>error: error validating "./job.yaml": error validating data: 
  ValidationError(CronJob.spec.jobTemplate.spec.template.spec): unknown 
  field "concurrencyPolicy" in io.k8s.api.core.v1.PodSpec; if you choose 
  to ignore these errors, turn validation off with --validate=false
  </code></pre>
  
  <p>I am probably either putting this property in the wrong place or calling it the wrong name, I just cannot find it in documentation. Thanks!</p>