Helm - Configmap - Replace only the contents of file and not File Names - kubernetes

Question

I have defined application.properties files in a config dir. Config dir is on the below structure.
config
application.properties
application-test.properties
application-dev.properties
application-prod.properties
I have created a helm chart to create the configmap. Helm chart is defined as below
apiVersion: v1
kind: ConfigMap
metadata:
name: nginx-configmap
data:
{{- (.Files.Glob "config/*").AsConfig | nindent 2 }}
I see that the configmap is created.
We are consuming the ConfigMap via environment variables in a running container using the envFrom property. (This in my deployment yaml file)
spec:
containers:
- envFrom:
- configMapRef:
name: nginx-configmap
I see that the values are stored as environment variables. However the variables are in lower cases.
server.port=8080
server.name=localhost
Since these are env variables, they have to be uppercase and . should be replaced with _. So, I have modifed my chart as below
data:
{{- (.Files.Glob "config/*").AsConfig | nindent 2 | upper | replace "." "_" }}
The generated configmap is as below
APPLICATION_PROPERTIES: |
SERVER_PORT = 8080
SERVER_NAME = LOCALHOST
Below is the env variables inside container
APPLICATION_PROPERTIES=SERVER_PORT = 8080
SERVER_NAME = LOCALHOST
My requirement is that only the contents of the file should be upper case and . should be replaced with _. The filename should not be converted. The filename should be as is.
Can this be achieved?

Answer 1

Try this:
apiVersion: v1
kind: ConfigMap
metadata:
name: nginx-configmap
data:
{{ $root := . }}
{{ range $path, $bytes := .Files.Glob "config/*" }}
{{ base $path }}: '{{ $root.Files.Get $path | nindent 2 | upper | replace "." "_" }}'
{{ end }}