Add values.schema.json to Grafana Helm charts

[luolong]

This will allow various IDE's to provide intellisense when authoring Grafana chart values.

[Danta1st]

This would be a very welcomed addition from my perspective.

Is there any tooling we could use to generate these as part of ci and perhaps push them to schemastore.org, or similar? I wouldn't mind doing some of the required work if there's any suggestions.

[ChristianCiach]

There is https://github.com/losisin/helm-values-schema-json and the README mentions ways of automation. But the generated schema leaves a lot to be desired:

• If the default-value for some attribute in values.yaml is null, the generated schema thinks that null is the only valid value for this attribute.
• It doesn't handle chart-dependencies, and Grafana helm charts use tons of dependencies.

It is probably impossible to reliably generate a schema for a given values.yaml. These schemas should probably be authored manually.

Edit: Fixed link, sorry!

[ChristianCiach]

https://github.com/dadav/helm-schema works very nicely and also adds dependency charts to the schema. I just tested it with the grafana-oncall chart and the resulting schema is very usable.

Also, this tool can be nicely integrated into github-actions, as seen in kubernetes/ingress-nginx#11295