feat: add K8S+Helm recommended/standard labels

[SLoeuillet]

Add standard/recommended labels as per :
https://kubernetes.io/docs/concepts/overview/working-with-objects/common-labels/
https://helm.sh/docs/chart_best_practices/labels/

I did keep the original labels like "app" but best practice is to "namespace" them like : canton.network/app

@isegall-da && @moritzkiefer-da, it supersedes : digital-asset/decentralized-canton-sync#365

[SLoeuillet]

Example output :

+ metadata:
+   labels:
+     app.kubernetes.io/component: wallet-web-ui
+     app.kubernetes.io/managed-by: Helm
+     app.kubernetes.io/instance: canton-val-devnet-wallet-web-ui
+     app.kubernetes.io/name: splice-validator
+     app.kubernetes.io/version: 0.3.17
+     helm.sh/chart: splice-validator-0.3.17
+     app.kubernetes.io/part-of: canton-val-devnet
+     app: wallet-web-ui
+     migration: "1"

[martinflorian-da]

Thanks for this initiative @SLoeuillet !

I did keep the original labels like "app" but best practice is to "namespace" them like : canton.network/app

Happy for us to consider this as a follow-up issue / PR. I'll make a note on our internal tracker.

Example output :

Yeah Ideally we'd have a way to check the Helm template rendering automatically (to avoid surprising changes)... some day...

Actual review:

In addition to my comment in the code we should IMO extend this fix to much more (all?) of the Splice Helm charts. For consistency and because it seems like an easy drive-by win (with a nice helper definition as suggested in my comment).

LMK if you're interested in making such changes to your PR! Either way, we can't directly merge external PRs here yet but I can apply "approved" changes here to our internal repo.

[martinflorian-da]

I suggest we extract this whole block into a reusable definition in cluster/helm/splice-util-lib/templates/_helpers.tpl. This avoids code duplication (this is a fairly large block that we'll want in many places).

I'd also argue that this is more consistent to our goal state for managing these Helm templates. See for example include "splice-util-lib.service-account" which we added recently.

[SLoeuillet]

I must admit that I didn't touch other components as I'm on Validator deployment only for now
But yes, best way is to use a template

I open PRs once I find some things which would make multiple deployments on the same K8S cluster fail as my intermediate goal is to have a validator on devnet, 1 on testnet & 1 on mainnet on the same cluster, and more distant goal, same for SV

Exemple : in previous PR, hardcoded PVC volume name, but it could be hardcoded DB name or DB username in case you use a unique PG server