How do I use json variables in a yaml file (Helm) - json

Question

I have a HELM values file which looks like so:
service:
environment: dev
spring_application_json: >-
{
"spring" : {
"boot" : {
"admin" : {
"client" : {
"enabled" : "false",
"url" : "http://website1",
"instance" : {
"service-base-url" : "http://website2",
"management-base-url" : "http://website3"
}
}
}
}
}
}
And a corresponding template file which grabs this value and inserts it as an environment variable to a container.
spec:
replicas: {{ .Values.replicaCount }}
template:
spec:
imagePullSecrets:
- name: {{ .Values.image.pullSecret }}
containers:
- name: {{ .Chart.Name }}
image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
imagePullPolicy: {{ .Values.image.pullPolicy }}
env:
- name: ENVIRONMENT
value: "{{ .Values.service.environment }}"
- name: SPRING_APPLICATION_JSON
value: "{{ .Values.service.spring_application_json }}"
However when I run the helm install I get the following error:
Error: YAML parse error on deployment.yaml: error converting YAML to JSON: yaml: line 40: did not find expected key
Which points to the line:
value: "{{ .Values.service.spring_application_json }}"
I believe its a problem with the way I'm trying to parse in a json string as a multiline environment variable? The ENVIRONMENT 'dev' variable works perfectly and this same YAML also works perfectly with docker-compose.

Answer 1

There's an example a bit like this in the docs for spring cloud dataflow but the format in their documentation has the quotes escaped.
I was able to recreate the error and get past it by changing the values file entry to:
service:
spring_application_json:
{
"spring" : {
"boot" : {
"admin" : {
"client" : {
"enabled" : "false",
"url" : "http://website1",
"instance" : {
"service-base-url" : "http://website2",
"management-base-url" : "http://website3"
}
}
}
}
}
}
And the deployment entry to:
- name: SPRING_APPLICATION_JSON
value: {{ .Values.service.spring_application_json | toJson | quote }}
Notice no quotes around this part as that is handled anyway.