minecraft-pi-reborn/launcher/src/run.sh

#!/bin/sh

set -e

# Check Root
if [ ! "$(id -u)" = '0' ]; then
    echo 'Must Run As Root' 1>&2
    exit 1
fi

# Check
if ! id user > /dev/null 2>&1; then
    # Create User Groups
    if [ -z "${USER_GID+x}" ]; then
        USER_GID='1000'
    fi
    groupadd --force --gid "${USER_GID}" user

    # Create User
    if [ -z "${USER_UID+x}" ]; then
        USER_UID='1000'
    fi
    useradd --shell /bin/sh --home-dir /home --no-create-home --uid "${USER_UID}" --gid "${USER_GID}" user

    # Add Other Groups
    if [ ! -z "${USER_OTHER_GIDS+x}" ]; then
        for gid in ${USER_OTHER_GIDS}; do
            groupadd --force --gid "${gid}" "group-${gid}"
            usermod -aG "${gid}" user
        done
    fi
fi

# Start
exec gosu user ./launcher