Support for YAML values in "valuesFrom" resource when using "targetPath"

[jozala]

Current solution

Currently when setting spec.valuesFrom.[n].targetPath, the value from ConfigMap/Secret referred is treated as a JSON or string. This is documented here with the information "targetPath supports the same formatting as you would supply as an argument to the helm binary using --set [path]=[value]".

Proposed feature

Make possible to use spec.valuesFrom.[n].targetPath to add root field(s) to the YAML values passed with valuesFrom.

Example

Helm Release

apiVersion: helm.toolkit.fluxcd.io/v2beta1
kind: HelmRelease
metadata:
  name: myapp
  namespace: apps
spec:
  interval: 5m
  releaseName: myapp
  chart:
    spec:
      chart: appchart-with-subchart
      sourceRef:
        kind: HelmRepository
        name: my-charts-repo
  valuesFrom:
    - kind: ConfigMap
      name: config-values
      targetPath: global # <-- targetPath set to pass values to subchart

Values ConfigMap

apiVersion: v1
kind: ConfigMap
metadata:
  name: config-values
  namespace: apps
data:
  values.yaml: |
    users:
      user1:
        alias: u1
      users2:
        alias: u2

Result values supplied to the HelmRelease

global:
  users:
    user1:
      alias: u1
    users2:
      alias: u2

Background

Current solution has limitations which is problematic in cases when using subcharts. We keep some configuration shared between applications in ConfigMaps and apply it with valuesFrom functionality.

However, some Helm charts have subcharts which would also like to use these values. To supply these values to subchart we need them to be prefixed with subchart name or "global". To achieve that we need to duplicate all the values to have "global" prefix in YAML.

With the proposed feature, we could set targetPath to "global" or subchart name and pass these values easily.

[joaocc]

Hi. Was there any analisys and/or decision on this request? We would also love being able to use more complete merge capabilities! Thanks