Feature Request: helm lint should verify that values used in charts are present in values.yaml

[dgn]

Hi! I'd like to see helm lint perform some checks against the values.yaml and the templates, namely that any usage of .Values.someField is cross-checked against the values.yaml file to make sure that it indeed contains someField.

Now, I know that this is sort of complex due to the nature of templating, but in a first iteration, I think a check that just verifies that any direct reference of a value (using .Values.someField) is backed up by a real value.

If there's interest in a feature like this, I would like to submit a PR to implement it

[gjenkins8]

It is frequently expected that the default values provided with a chart are incomplete. And that the user (chart installer) is expected to provide additional values. For this reason I don't think it really works for lint to verify that the default values are complete.

Better I think would be to provide a jsonschema with the chart. Which verifies values at install time.