Cronjob leaves behind pods after jobs are deleted

[andrewsav-bt]

What happened:

There seems to be a regression after 1.13 release. A Cronjob with default settings does not clean up completed pods. The job themselves are getting deleted as expected, but the pods are left behind. This seems to be related to #70872 @juanvallejo

What you expected to happen:

Expected the pods for now non-existent child jobs of a cronjob to be cleaned up. This is the way it used to work prior to 1.13/

How to reproduce it (as minimally and precisely as possible):

run kubectl apply on this manifest:

kind: CronJob
apiVersion: batch/v1beta1
metadata:
  name: cjtest
spec:
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:
        metadata:
          name: cjtest
          labels:
            app: cjtest
        spec:
          restartPolicy: "Never"
          containers:
          - name: cjtest
            image: hello-world

Wait, more than 3 minutes, observe, that while only 3 successful jobs are present, the pods from now deleted jobs are left behind and never get deleted.

Anything else we need to know?:

@liggitt pointed out the following relevant places in the code base:

https://github.com/kubernetes/kubernetes/blob/master/pkg/registry/batch/job/strategy.go#L53
https://github.com/kubernetes/kubernetes/blob/master/pkg/controller/cronjob/injection.go#L121

deleting a job orphans pods by default and the cronjob controller doesn't do anything different than the default when deleting

Environment:

• Kubernetes version (use kubectl version): 1.13.0
• Cloud provider or hardware configuration: ubuntu VM in vSphere
• OS (e.g. from /etc/os-release): 16.04.5 LTS (Xenial Xerus)
• Kernel (e.g. uname -a): 4.4.0-135-generic
• Install tools: kubeadm

/kind bug

[andrewsav-bt]

/sig apps @liggitt @soltysh @juanvallejo

[mauilion]

Should include a known issues in 1.13.0 as well
/priority critical-urgent

[soltysh]

Lemme see if I can easily reproduce this.

[liggitt]

/milestone v1.13

[soltysh]

Fixes are in #71801 (master) and #71802 (1.13).