#!/bin/bash

set -e

# 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}

if [ -e "/etc/ltsp/ltsp.conf.in" ] && cat "/etc/ltsp/ltsp.conf.in" | grep -v "#" | grep -q "@rootpw@"; then

	# Drop previous ltsp.conf (yes, we want to do that!)
	rm /etc/ltsp/ltsp.conf
	touch /etc/ltsp/ltsp.conf
	chown root:root /etc/ltsp/ltsp.conf
	chmod 0600 /etc/ltsp/ltsp.conf

	echo "# THIS FILE IS RECREATED DAILY FROM /etc/ltsp/ltsp.conf.in - DON'T EDIT THIS FILE" >> /etc/ltsp/ltsp.conf
	echo >> /etc/ltsp/ltsp.conf

	# configure LTSP before creating ltsp.img and iPXE config
	host_rootpw=$(cat /etc/shadow | grep -E "^root:" | cut -d":" -f2)
	[ "$host_rootpw" ] && export host_rootpw && perl -p -e "s/\@rootpw\@/\$ENV{host_rootpw}/g" "/etc/ltsp/ltsp.conf.in" >> "/etc/ltsp/ltsp.conf"
	unset host_rootpw
fi

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 "${chroot_dir} " || true; done)"
ltsp_chroots="${ltsp_chroots%%?*( )}"

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

# let's update ltsp.img (LTSP initrd) and LTSP's iPXE boot menu configuration, just in case...
ltsp initrd
ltsp ipxe