feat: add value for istio revision namespace labels

[josh-thisisbud]

Allows using istio with a revision-based set up, that is, applying istio.io/rev labels to the Namespaces.

closes: #62

[thesuperzapper]

@josh-thisisbud thanks for the PR!

However, there are a few important things missing:

• Please add a new default value and docstring for deploykf_dependencies.istio.revision
• The revision label values should be wrapped in quotes by piping to {{ ...revision | quote }} so we don't pass a number type for all-number labels

The profile namespaces will also need this label, but this may be a challenge, because even though you can tell the profile-controller to add labels under:

• https://github.com/deployKF/deployKF/blob/main/generator/templates/manifests/deploykf-core/deploykf-dashboard/values.yaml#L201-L219
• https://github.com/deployKF/deployKF/blob/main/generator/templates/manifests/deploykf-core/deploykf-dashboard/templates/profile-controller/ConfigMap-namespace-labels.yaml

The problem is that even if we did something fancy like automatically injecting a deploykf_dependencies.istio.revision label to those values, the profile controller is not able to update existing labels (meaning the changes to revision would not be reflected in the profile namespaces).

So we either need to either:

1. Make the profile controller (upstream in Kubeflow) able to reconcile labels
2. Set the istio revision for profiles with a Kyverno ClusterPolicy

The second one is obviously the easiest, but I am always a bit hesitant to invoke the nuclear weapon that is Kyverno (unless absolutely necessary, which this case probably is).

Interested to know your thoughts.

[josh-thisisbud]

I'll make the changes requested shortly and I'm inclined to agree that option #1 seems like the better option.

In the interim, we've started using the kubeflow manfests repo for our deployment so I'm not sure how much time I can give to resolving further issues with deployKF.