How to Merge the contents of ConfigMaps in Kubernetes

Question

We have our app specific properties specified in the below files

application.properties
application-dev.properties
application-qa.properties

While creating a configmap in kubernetes, I wanted to merge the contents into one single file. Is it possible to merge the contents?

I know we can achieve through kustomize. However we are using Helm Charts and we are not using kustomize.

Answer 1

Place the ConfigMap files inside a folder, and then pass the folder path to the kubectl command:

kubectl create configmap config-name --from-file=path_to_the_folder

Answer 2

try this simple trick

cat application*.properties > app.properties && kubectl create configmap myconfigmap --from-file=app.properties

you can use app.properties in helm chart