if [[ ${1:-} == '--su' ]]; then
if [[ -z $( docker ps -qf name=$CTNR_NAME ) ]]; then
echo "Starting new container $CTNR_NAME"
# match host user ID and group ID
docker exec -it -u root $CTNR_NAME groupmod -g "$GROUP_ID" rungroup
docker exec -it -u root $CTNR_NAME usermod -u $UID runuser
# some files need to be re-owned by runuser
docker exec -it -u root $CTNR_NAME chown runuser /var/run/docker.sock
echo "Container $CTNR_NAME is already running"
echo "Shelling into $CTNR_NAME container"
if [[ $run_as_root == true ]]; then
docker exec -it --user root $CTNR_NAME /bin/bash
docker exec -it --user runuser $CTNR_NAME /bin/bash