I am using kubectl create configmap command as follows:

kubectl create configmap config-multi-yaml-files --from-file=templates/1template.yaml --from-file=apps/app1.yaml --from-file=app2/app2.yaml  --dry-run=true -o yaml > output.yaml

The resultant configmap do have file names (app1.yaml, app2.yaml) like this:

apiVersion: v1
data:
  app1.yaml: |-
  groups:
  - name: sample
    rules:
    - alert: alert

How can I use this command so that I do have a configmap from multiple yamls, but do not have the respective file names in the resultant configmap.

Any pointers are appreciated.

Thanks.