enhancement: propagate the annotations and labels from the CR to all child resources

[olevski]

This should be an option in the CRD. By default it should not propagate (so that we do not break the API since we currently do not propagate).

Actually it may be nicer to have 2 fields, one for annotations and one for labels.

When set all annotations and labels from the CR should be added to the children.

EDIT:

At the CRD we can add Spec.Template.Metadata.Labels and Spec.Template.Metadata.Annotations. The type for each can come from the k8s library.

In the rare case of collisions the original child annotation or label should prevail and not be replaced by the one from the CR. This is because the original child annotation or label can be used for example for auto scaling or similar things.

By default the template metadata and labels are empty and so no value is added to the children. Just like now.

[olevski]

Also for the statefulset these should propagate all the way to the Pod.

[leafty]

I suggest having allow lists of annotations/label domains, e.g. "allow renku.io/* annotations". This way there is much less chance of collision with k8s or other CRD annotations clashing.

Or support listing annotations with wildcard, e.g.:

propagateAnnotations:
  - renku.io/*
  - example.org/a-specific-annotation
propagateLabels:
  - renku.io/*
  - app.kubernetes.io/name

[leafty]

Case in point: things like app.kubernetes.io/created-by would most likely break controllers if propagated.

[olevski]

I think I would rather actually just have annotations or labels that you have to specify that are just applied to all children. This way we dont have to do partial matches / searches across the keys as with something like renku.io/*.

And it is also closer to how you can specify the pod annotations/labels from a deployment or statefulset.

[leafty]

That works too

[olevski]

For example a deployment has:

spec:
  template:
    metadata:
      labels:
        labelName: someValue
     annotations:
       annotationName: someValue