cronjob: Add labels to pod template

[pfaelzerchen]

Description of the change

Currently, under cronjob.cronjob.label one can only specify labels for the cronJob object itself. It would be nice to be able to specify labels for the cronjob pods within the spec.jobTemplate.spec.template.metdata.labels. For example by:

cronjob:
  enabled: true
  type: cronjob

  cronjob:
    jobLabel:
      app: nextcloud-cron

for

spec:
  jobTemplate:
    spec:
      template:
        metadata:
          labels:
            app: nextcloud-cron

Benefits

You can specify netpol rules for the job pods. This is mandatory if you already use fine-grained netpol rules for service communication, as the job would fail then.

Possible drawbacks

Can't think of any.

[mazinsfr]

Hi there!

It is not obvious because podLabels section is missing in the values.yaml but you can add labels to the CronJob (check here):

cronjob:
  enabled: true
  type: cronjob
  cronjob:
    labels:
      app: nextcloud-cronjob

# Missing section in the values.yaml
podLabels:
  app: nextcloud-cronjob-pod

This gives you the following cronjob:

apiVersion: batch/v1
kind: CronJob
metadata:
  name: release-name-nextcloud-cron
  labels:
    [...]
    app: nextcloud-cron
spec:
  jobTemplate:
    metadata:
      labels:
        [...]
        app: nextcloud-cronjob-pod

These labels are shared with the Nextcloud pod. If you want distinct network policies for Nextcloud pod and cronjob pod, this is not possible now.

Maybe we should keep the common section but add specific podLabels, podAnnotations, and resources sections for both the Nextcloud pod and the CronJob pod.

cronjob:
  enabled: true
  type: cronjob
  cronjob:
    # Cronjob pod labels
    podLabels:
      app: nextcloud-cronjob-pod
    # Cronjob labels
    labels:
      app: nextcloud-cronjob

# Common pod labels
podLabels:
  app: nextcloud-app

nextcloud:
  # Nextcloud pod labels
  podLabels:
    app: nextcloud-pod

[pfaelzerchen]

@mazinsfr Thanks for your help. I was well aware of this possibility, but it doesn't work. The labels are added to the Job object, but not to the Pod it runs. So the Pod still does not get access to the database.