To launch the phpMetrics into the container, run:
docker run --rm --user $(id -u):$(id -g) --volume $(pwd):/data/www nicodocker91/phpmetrics <options> ${ROOT_FOLDER}
The only volume available to mount is /data.
The entrypoint is /data/www.
Run the following command to read all options available:
docker run --rm nicodocker91/phpmetrics --help