Helm Variables inside ConfigMap File

Question

So I had a ConfigMap with a json configuration file in it, like this:

apiVersion: v1
kind: ConfigMap
metadata:
  name: my-config-map
data:
  config.json: |+
  {
    "some-url": "{{ .Values.myApp.someUrl }}"
  }

But I've moved to having my config files outside the ConfigMap's yaml, and just referencing them there, like this:

apiVersion: v1
kind: ConfigMap
metadata:
  name: my-config-map
data:
  config.json: |-
{{ .Files.Get .Values.myApp.configFile | indent 4 }}

But now I want my json to look like the following

{
  "some-url": "{{ .Values.myApp.someUrl }}"
}

The only thing I tried is what I just showed. I 'm not even sure how to look for this answer.

Is it even possible?

score 2 · Accepted Answer · answered Aug 25 '22 at 16:15

At the time of reading the file, its content is a string. It's not evaluated as template, and therefore you cannot use variables like you do.

However, helm has a function for this purpose specifically called tpl:

apiVersion: v1
kind: ConfigMap
metadata:
  name: my-config-map
data:
  config.json: |- 
{{ tpl (.Files.Get .Values.myApp.configFile) $ | indent 4 }}

The tpl function takes a template string and renders it with some context. This is useful when you have template snippets in your values file or like in your case in some files content.

Helm Variables inside ConfigMap File

1 Answers1