[D]ocker [O]ne [OF]f script (run a container inside the current working directory)

doof.sh

#!/usr/bin/env sh

## Features:
## - host's working directory is mounted to random location as the container's working directory
## - uid/gid of the current user are preserved inside the container
## - a host tmp dir will be mounted as /home/user and published as HOME environment variable inside the container
## - all EXPOSED ports will be published (check `docker port $(docker ps -q|head -n1)`).
## - container will be removed on exit
##
## Examples:
### doof pypy                                       # start a pypy repl in $PWD
### doof pypy pypy3 script.py                       # run `$PWD/script.py` inside the pypy container
### doof ruby /bin/bash                             # run bash inside a ruby container
### doof elasticsearch -Dpath.data=/home/user/data  # run elasticsearch, write inside the temporary home

CONTAINER="${1:--h}"
if [ "$#" -gt 1 ]
then
    shift 1
    CMD=$@
else
    CMD=
fi

if [ $CONTAINER = "-h" ]
then
    echo "Run a Docker One-OFf command."
    echo "Usage:\n\t$(basename $0) IMAGE_NAME [CMD inside container]"
    exit
fi

DIR=$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 8 | head -n 1)
HOME_DIR=$(mktemp -d)

check_ports () {
    RUNNING="$(docker ps -q|head -n1)"
    if [ ${#RUNNING} -gt 0 ]
    then 
        PORTS=$(docker port $RUNNING)
        # FIXME: formatting is off
        printf "\n\nDOOF PORTS:\n\n$PORTS\n\n"
    fi
}

(sleep 3 && check_ports) &

docker run --rm -it --publish-all \
    -v $HOME_DIR:/home/user \
    -e HOME=/home/user \
    -v $(pwd):/$DIR \
    --workdir /$DIR \
    --user $(id -u):$(id -g) \
    "$CONTAINER" $CMD