#!/bin/bash

# Copyright (C) 2018 Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
#
# This script is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This script is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the
# Free Software Foundation, Inc.,
# 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.

LTSP_OPT="/srv/ltsp"

# work around libpam-tmpdir not working for the
# root user and /tmp being too small anyway...
TMPDIR="/srv/tmp"
export TMPDIR
mkdir -p ${TMPDIR}/
chown root:root ${TMPDIR}
chmod 1777 ${TMPDIR}

ltsp_chroots=$(ls "${LTSP_OPT}" | while read chroot_dir; do test ! -h "${LTSP_OPT}/${chroot_dir}" -a -x "${LTSP_OPT}/${chroot_dir}/bin/bash" && echo -n "${chroot_dir} "; done)

for chroot in ${ltsp_chroots}; do

	if [ -e "${LTSP_OPT}/${chroot}/chroot-upgrade-in-process" ]; then
		echo "Chroot ${LTSP_OPT}/${chroot} is currently being upgraded. Skipping..."
		continue
	fi

	latest_upgrade=$(ls ${LTSP_OPT}/${chroot} | grep -E 'chroot-updated_[0-9]{8}$' | sort | tail -n1)

	if [ -z "${latest_upgrade}" ]; then
		echo "chroot ${LTSP_OPT}/${chroot} lacks the chroot-updated_<date> file. Can't proceeed. Skipping..."
		continue
	fi

	if [ -e "${LTSP_OPT}/${chroot}/${latest_upgrade}.squashfs-created" ]; then
		echo "chroot ${LTSP_OPT}/${chroot}'s squashfs image is up-to-date. Skipping..."
	else
		if ltsp image "${LTSP_OPT}/${chroot}"; then
			rm -f "${LTSP_OPT}/${chroot}/chroot-updated_*.squashfs-created"
			touch "${LTSP_OPT}/${chroot}/${latest_upgrade}.squashfs-created"
		fi
	fi 

done