Only the old values.yaml is used instead of merging them with new ones

[mszostok]

Description

In the current approach, we set the reuseValues: true in our Helm runner manifests. By doing so, we want to reuse user supplied values. In that way, we preserve all customization e.g. increased resources etc.

Expected behavior

The user supplied values are preserved, but at the same time new values all also available.

Actual behavior

The new values.yaml is replaced with old values.yaml causing that new functionality is cannot be used. For example, when new value notes.printInsecure was added, the installation failed with such error:

while executing runner: while starting action: while running Helm command "upgrade": while installing Helm chart: template: capact/templates/NOTES.txt:6:13: executing "capact/templates/NOTES.txt" at <.Values.notes.printInsecure>: nil pointer evaluating interface {}.printInsecure

and upgrade was not possible.

Workaround

For now, we set new values in Helm runner overrides. As a result, they are merged with old values.yaml and new functionality can use them. See: #357

Implementation suggestion

To support that we can add new option to Helm CLI, sth like reuse-user-provided-values. Currently, there is only an option with pure override: https://github.com/helm/helm/blob/179f90151d5ecb4aa3d35ada35e82b5c1e791752/pkg/action/upgrade.go#L443-L458. But first, we need to create an issue and discuss the approach with Helm maintainers.

So as an intermediate step, we can implement that functionality directly in Helm runner.