I want to mount a shell script template into a container.
I have the following configmap.yaml:
apiVersion: v1
kind: ConfigMap
metadata:
name: {{ template "myservice-chart.fullname" . }}--scripts-configmap
labels:
app: {{ template "myservice-chart.name" . }}
chart: {{ template "myservice-chart.chart" . }}
release: {{ .Release.Name }}
heritage: {{ .Release.Service }}
data:
setup: |
{{ include "setup" . | indent 4 }}And this is my setup.tpl:
{{- define "setup" }}
#!/bin/bash
echo "Hello world!"
{{- end }}When I do a Helm dry-run, Helm generates this (valid) YAML:
...
apiVersion: v1
kind: ConfigMap
metadata:
name: listening-donkey-myservice-chart-quorum-scripts-configmap
labels:
app: myservice-chart
chart: myservice-chart-0.1.0
release: listening-donkey
heritage: Tiller
data:
setup: |
#!/bin/bash
echo "Hello world!"
...
When I run it without --dry-run, it generates this error:
configmap.yaml: error converting YAML to JSON: yaml: line 13: did not find expected key
It looks like Helm creates a useless empty line below setup: |, hence incorrect indentation.
This is how I fixed it:
...
data:
setup: |
# Useless line to prevent "did not find expected key"
{{ include "setup" . | indent 4 }}According to helm chart template guide:
The curly brace syntax of template declarations can be modified with special characters to tell the template engine to chomp whitespace. {{- (with the dash and space added) indicates that whitespace should be chomped left, while -}} means whitespace to the right should be consumed. Be careful! Newlines are whitespace!
So, in order to prevent an useless empty line below setup: | the configmap.yaml should be the following:
apiVersion: v1
kind: ConfigMap
metadata:
name: {{ template "myservice-chart.fullname" . }}--scripts-configmap
labels:
app: {{ template "myservice-chart.name" . }}
chart: {{ template "myservice-chart.chart" . }}
release: {{ .Release.Name }}
heritage: {{ .Release.Service }}
data:
setup: |
{{- include "setup" . | indent 4 }}