docker-footprint.sh script to check docker space

#!/bin/bash
#
# Use
# ./docker-footprint.sh start 10   (starts 10 containers from node image <900MB )
# ./docker-footprint.sh more 10    (adds 10 more containers to first created with start)
# ./docker-footprint.sh stop       (stops all running or stoped container with name test??)
#
# Author Rodolfo Pilas <pilasguru@gmail.com> 2021-02-02
# Do What The Fuck You Want To Public License (WTFPL)

function docker_size {
   echo Docker space:
   docker system df
   du -sh /var/lib/docker
   echo
}

case $1 in
   start)
      docker_size
      for i in $(seq -w $2); do
         docker container run --name=test$i -d --rm --entrypoint="/bin/sh" node -c 'while true; do sleep 60; done'
      done
      docker_size
      ;;
   stop)
      echo Stopping containers with name test:
      for i in $(docker ps --format '{{ .Names }}' | grep test); do
     docker stop $i
      done
      docker_size
      ;;
   more)
      LAST=`docker ps --format '{{ .Names }}' | grep test | sort | tail -1 | sed s/test//`
      START=$(( $LAST + 1 ))
      END=$(( $START + $2 ))
      for i in $(seq -w $START $END); do
         docker container run --name=test$i -d --rm --entrypoint="/bin/sh" node -c 'while true; do sleep 60; done'
      done
      docker_size
      ;;
   *)
      echo "Usage: $0 start/stop/more COUNT"
      ;;
esac
exit 0