helm --set to select environment - kubernetes-helm

Question

Struggling with some helm templating...
I'm trying to pass a separate yaml file with springboot parameters to helm, and have them split by environment... then I want to pass the environment to helm using --set env=staging
Feels like I've tried everything but clearly I'm lacking a fundamental understanding...
My _helpers.tpl contains these:
{{- define "env" }}
{{- printf "%s" .Values.env }}
{{- end }}
{{ define "configmap.metadata" }}
name: {{ .Values.name }}-config
{{ end }}
{{ define "configmap.properties" }}
{{ index .Values.environment (include "env" .) "properties" | indent 4 }}
{{ end }}
The template for the config map:
apiVersion: v1
kind: ConfigMap
metadata:
{{ include "configmap.metadata" . }}
data:
app.properties: |-
{{ include "configmap.properties" .}}
And the yaml file containing the properties looks like this:
environment:
staging:
properties:
spring:
datasource:
url: something
username: something
password: something
app1:
key: something
secret: something
baseUri: something
app2:
bootstrap_server: something
bootstrap_port: something
registry_schema: something
production:
properties:
spring:
etc, etc
And then I want to select the environment using set. I'm testing with:
helm template test . -f values.yaml -f properties.yaml --set env=staging
I think I've just tried so many things that I just can't see the wood for the trees! The error I'm seeing is:
Error: template: microservice/templates/configmap.yaml:7:7: executing "microservice/templates/configmap.yaml" at <include "configmap.properties" .>: error calling include: template: microservice/templates/_helpers.tpl:56:76: executing "configmap.properties" at <4>: wrong type for value; expected string; got map[string]interface {}
EDIT:
After tweaking, I'm still getting an error, but I'm seeing something in the configmap.. but I wonder if the error is due to the 8 spaces on the first line..
data:
app.properties: |-
app2:
bootstrap_port: something
bootstrap_server: something
registry_schema: something
app1:
baseUri: something
key: something
secret: something
spring:
datasource:
password: something
url: something
username: something

Answer 1

I think your actual error message is around the way you're using the .Values.environment.production.properties value. It's a YAML map, but the indent function expects it to be a string. You should be able to see some odd indentation and maybe an odd [map spring [map datasource ...]] string if you use the helm template --debug option.
When you go to render the ConfigMap, you need to make sure to do two things. Since the data you have is structured properties, you need to use the lightly-documented toYaml function to convert it back to YAML. This will begin at the first column, so you need to apply the indent function to it, and then you need to make sure the markup that invokes it is also at the first column (indent should be the only thing that supplies indentation).
data:
app.properties: |-
{{ include "configmap.properties" . | indent 4}}
{{/*- starts at column 1, but includes the `indent` function */}}
{{ define "configmap.properties" }}
{{- index .Values.environment (.Values.env) "properties" | toYaml }}
{{/*- starts at first column, includes `toYaml`, does not include `indent` */}}
{{- end }}