fix-permissions

#!/bin/bash
# set permissions on a directory
# after any installation, if a directory needs to be (human) user-writable,
# run this script on it.
# It will make everything in the directory owned by the group ${NB_GID}
# and writable by that group.
# Deployments that want to set a specific user id can preserve permissions
# by adding the `--group-add users` line to `docker run`.

# uses find to avoid touching files that already have the right permissions,
# which would cause massive image explosion

# right permissions are:
# group=${NB_GID}
# AND permissions include group rwX (directory-execute)
# AND directories have setuid,setgid bits set

set -e

for d in "$@"; do
    find "${d}" \
        ! \( \
            -group "${NB_GID}" \
            -a -perm -g+rwX \
        \) \
        -exec chgrp "${NB_GID}" {} \; \
        -exec chmod g+rwX {} \;
    # setuid, setgid *on directories only*
    find "${d}" \
        \( \
            -type d \
            -a ! -perm -6000 \
        \) \
        -exec chmod +6000 {} \;
done