post_install() {
    # Add rserve user and group.
    getent group rserve &>/dev/null || groupadd -g 32749 -r rserve >/dev/null
    getent passwd rserve &>/dev/null || useradd -u 32749 -m -d /home/rserve \
-s /bin/false -r -g rserve rserve >/dev/null    
    # Exec the chmod just like in the Makefile.
    chmod 750 /home/rserve

    # Add rsd user and group.
    getent group rsd &>/dev/null || groupadd -r rsd >/dev/null
    getent passwd rsd &>/dev/null || useradd -s /bin/false \
-r -g rsd rsd >/dev/null

    # This is explained in the Arch Wiki. It seems that anyone belonging to the 
    # docker group has root capablities, so creating a separate user to run 
    # Docker is necessary in my opinion.
    gpasswd -a rsd docker >/dev/null

    chown -R rsd:rsd /usr/share/rserve-sandbox-docker

    printf "\n\n%s\n\n" "Before starting the service \ 
you must run \ 
sudo -u rsd rserve-sandbox-docker -i"
    printf "%s\n\n" "You can then start and enable \
rserve-sandbox-docker.service to run the server."
}

post_remove() {
    printf "\n\n%s\n" "To remove images and containters: \
rm -rf /var/lib/docker \
as described in \
<https://docs.docker.com/engine/installation/linux/archlinux/#/uninstallation>"
    printf "%s\n\n" "You can also remove /home/rserve \
as well as rserve and rsd users and groups."
}