$ mkdir -p configfiles
$ for i in $(seq 1 5); do \
    echo "This is file $i" >> "configfiles/file_${i}.txt"; \
  done
$ dir2cm -dir configfiles -name my-configs

---
apiversion: v1
kind: ConfigMap
metadata:
  name: my-configs
  labels: {}
data:
  file_1.txt: |
    This is file 1
  file_2.txt: |
    This is file 2
  file_3.txt: |
    This is file 3
  file_4.txt: |
    This is file 4
  file_5.txt: |
    This is file 5

docker run --rm -v "$(pwd)/configfiles:/data" cmattoon/dir2cm -name foobar

apiversion: v1
kind: ConfigMap
metadata:
  name: foobar
  labels: {}
data:
  file_1.txt: |
    This is file 1
  file_2.txt: |
    This is file 2
  file_3.txt: |
    This is file 3
  file_4.txt: |
    This is file 4
  file_5.txt: |
    This is file 5