(DOCUMENTATION) HelmRelease: set helm values array using valuesFrom

[egorksv]

Please update HelmRelease documentation to define key = '{value1, value2, value3}' ConfigMap syntax.

Discussed in #3909

^{Originally posted by hoffimar May 23, 2023}
I would like to use the values override feature of the helm-controller (https://fluxcd.io/flux/components/helm/helmreleases/#values-overrides) and set an array/list in the helm values of my helm release. But I am not clear about the syntax to use.

In the helmrelease I have this reference to a configmap:

    - kind: ConfigMap
      name: array-test
      optional: true
      targetPath: global.theList
      valuesKey: array-test.yaml

The configmap is defined like this:

apiVersion: v1
data:
  array-test.yaml: |-
    - type: apple
      count: 2
    - type: banana
      count: 3
kind: ConfigMap
metadata:
  name: array-test

Using helm -n default my-release get values I see that the values are updated, but are a string instead of a list.

global:
  theList: |-
    - type: apple
      count: 2
    - type: banana
      count: 3

As I would like to iterate over the list/array with range in the helm chart implementation, is there any way to make the configmap entries available as list directly? Or would I need to use fromYaml (from https://helm.sh/docs/chart_template_guide/function_list/#type-conversion-functions) in the helm chart to convert the string to a list first?