Support resolving Helmfile version templates referencing values.yaml

[Sboti03]

Problem

In many Helmfile setups, chart versions are centralized in a values file and referenced via templates instead of being hardcoded in the release.

This is especially common when using templated Helmfile files (e.g. helmfile.yaml.gotmpl).

Example:

helmfile.yaml.gotmpl

releases:
  - name: my-service
    chart: base/my-service
    version: |-
      {{ .Environment.Values.versions.myService }}

values.yaml (or environment values)

versions:
  myService: 1.2.0

Currently, Renovate cannot detect or update such dependencies because the version is not a literal value in the Helmfile.

Current workaround

This can be solved using customManagers.regex with inline annotations, but:

• it is fragile
• a small typo or accidental change can break detection entirely
• it is hard to maintain and not Helmfile-aware

Proposal

Add support for resolving simple Helmfile template references like:

{{ .Environment.Values.versions.<key> }}

So that Renovate can:

• detect the chart (base/my-service)
• resolve the referenced version key (versions.myService)
• read the actual version from values.yaml
• update that value directly

Why this matters

This pattern is widely used to:

• centralize version management
• reuse versions across multiple releases
• keep Helmfile definitions clean

Native support would remove the need for fragile regex-based solutions and make Helmfile support significantly more robust.

Contribution

If this is considered a valid feature, I would be happy to work on an implementation.