#!/bin/bash

#
# lxc: linux Container library

# Authors:
# Niels Rogalla <niro@magellan-linux.de>

# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.

# This library 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
# Lesser General Public License for more details.

# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

die() { echo "ERROR: $@"; exit 1; }

configure_magellan()
{
	local rootfs="$1"
	local hostname="$2"

	echo "Setting up rootfs..."

	# fix locales first
	if [[ -z ${LANG} ]] && [[ -z ${LC_ALL} ]]
	then
		sed -i "s:^#\(en_US..*\):\1:g" ${rootfs}/etc/locale.gen
		LC_ALL=C chroot ${rootfs} /usr/sbin/locale-gen
	elif [[ ! -z ${LANG} ]]
	then
		sed -i "s:^#\(${LANG}\):\1:g" ${rootfs}/etc/locale.gen
		echo "LANG=${LANG}" > ${rootfs}/etc/env.d/01locale
		LC_ALL=C chroot ${rootfs} /usr/sbin/locale-gen
		LC_ALL=C chroot ${rootfs} /sbin/env-rebuild
	elif [[ ! -z ${LC_ALL} ]]
	then
		sed -i "s:^#\(${LC_ALL}\):\1:g" ${rootfs}/etc/locale.gen
		echo "LC_ALL=${LC_ALL}" > ${rootfs}/etc/env.d/01locale
		LC_ALL=C chroot ${rootfs} /usr/sbin/locale-gen
		LC_ALL=C chroot ${rootfs} /sbin/env-rebuild
	fi

	# configure the inittab
	cat <<EOF > ${rootfs}/etc/inittab
id:3:initdefault:
si::sysinit:/etc/rc.d/init.d/rc sysinit
l0:0:wait:/etc/rc.d/init.d/rc 0
l1:S1:wait:/etc/rc.d/init.d/rc 1
l2:2:wait:/etc/rc.d/init.d/rc 2
l3:3:wait:/etc/rc.d/init.d/rc 3
l4:4:wait:/etc/rc.d/init.d/rc 4
l5:5:wait:/etc/rc.d/init.d/rc 5
l6:6:wait:/etc/rc.d/init.d/rc 6
su:S016:once:/sbin/sulogin
1:2345:respawn:/sbin/agetty console 38400
2:2345:respawn:/sbin/agetty tty2 38400 linux
3:2345:respawn:/sbin/agetty tty3 38400 linux
4:2345:respawn:/sbin/agetty tty4 38400 linux
5:2345:respawn:/sbin/agetty tty5 38400 linux
6:2345:respawn:/sbin/agetty tty6 38400 linux
x:a:once:/etc/X11/startxdm
EOF

	# configure the network using dhcp
	cat <<EOF > ${rootfs}/etc/conf.d/net.eth0
ONBOOT="yes"
NETWORKING="dhcp"
EOF

	# set the hostname
	cat <<EOF > ${rootfs}/etc/hostname
${hostname}
EOF

	# remove /, /boot, swap from fstab (\s = space)
	sed -i -e '/\s\/\s/d' -e '/\s\/boot\s/d' -e '/\sswap\s/d' ${rootfs}/etc/fstab

	# remove pointless services in a container
	chroot ${rootfs} /sbin/rc-config del checkfs
	chroot ${rootfs} /sbin/rc-config del setclock

	#echo "root:foobar" | chroot ${rootfs} chpasswd
	chroot ${rootfs} usermod -p $(openssl passwd -1 foobar) root
	echo "Root password is 'foobar', please change!"

	# create missing device nodes
	[[ ! -e ${rootfs}/dev/null ]] && mknod -m 666 ${rootfs}/dev/null c 1 3
	[[ ! -e ${rootfs}/dev/zero ]] && mknod -m 666 ${rootfs}/dev/zero c 1 5
	[[ ! -e ${rootfs}/dev/random ]] && mknod -m 666 ${rootfs}/dev/random c 1 8
	[[ ! -e ${rootfs}/dev/urandom ]] && mknod -m 666 ${rootfs}/dev/urandom c 1 9
	[[ ! -e ${rootfs}/dev/pts ]] && mkdir -m 755 ${rootfs}/dev/pts
	[[ ! -e ${rootfs}/dev/shm ]] && mkdir -m 1777 ${rootfs}/dev/shm
	[[ ! -e ${rootfs}/dev/tty ]] && mknod -m 666 ${rootfs}/dev/tty c 5 0
	[[ ! -e ${rootfs}/dev/console ]] && mknod -m 600 ${rootfs}/dev/console c 5 1
	[[ ! -e ${rootfs}/dev/tty0 ]] && mknod -m 666 ${rootfs}/dev/tty0 c 4 0
	[[ ! -e ${rootfs}/dev/tty1 ]] && mknod -m 666 ${rootfs}/dev/tty1 c 4 1
	[[ ! -e ${rootfs}/dev/tty2 ]] && mknod -m 666 ${rootfs}/dev/tty2 c 4 2
	[[ ! -e ${rootfs}/dev/tty3 ]] && mknod -m 666 ${rootfs}/dev/tty3 c 4 3
	[[ ! -e ${rootfs}/dev/tty4 ]] && mknod -m 666 ${rootfs}/dev/tty4 c 4 4
	[[ ! -e ${rootfs}/dev/tty5 ]] && mknod -m 666 ${rootfs}/dev/tty5 c 4 5
	[[ ! -e ${rootfs}/dev/tty6 ]] && mknod -m 666 ${rootfs}/dev/tty6 c 4 6
	[[ ! -e ${rootfs}/dev/full ]] && mknod -m 666 ${rootfs}/dev/full c 1 7
	[[ ! -e ${rootfs}/dev/initctl ]] && mknod -m 600 ${rootfs}/dev/initctl p
	[[ ! -e ${rootfs}/dev/ptmx ]] && mknod -m 666 ${rootfs}/dev/ptmx c 5 2

	return 0
}

download_magellan()
{
	local cache="$1"
	local arch="$2"
	local distribution="unstable"
	local mageprofile="$(basename $(readlink /etc/mage-profile))"
	local extrapackages="dialog iproute2 openssh"

	# check the mini magellan was not already downloaded
	mkdir -p "${cache}/partial-${arch}"
	if [ $? -ne 0 ]
	then
		echo "Failed to create '${cache}/partial-${arch}' directory"
		return 1
	fi

	# setup magerc
	cat <<EOF > ${cache}/partial-${arch}/mage.rc.bootstrap
ARCH="${arch}"
MAGE_DISTRIBUTION="${distribution}"

MAGEDIR="/usr/mage"
PKGDIR="/var/cache/mage/packages"
BUILDDIR="/var/tmp/magebuild"
INSTALLDB="/var/db/mage"
VIRTUALDB_DEFAULTS="/etc/mage-profile/virtuals.defaults"
VIRTUALDB_FILE="\${INSTALLDB}/virtuals"

VERBOSE="off"
MAGEDEBUG="off"

MIRRORS="http://magellan-linux.de/magellan/magellan-dev/svn/\${MAGE_DISTRIBUTION}"
RSYNC="rsync://magellan-linux.de/mage-svn"

PACKAGES_SERVER_PATH="packages/\${ARCH}"
MAGE_UNINSTALL_TIMEOUT=0
EOF

	# download a mini magellan into a cache
	echo "Downloading magellan minimal ..."
	mage-bootstrap --profile ${mageprofile} --root ${cache}/partial-${arch} --magerc ${cache}/partial-${arch}/mage.rc.bootstrap --update-tarball
	if [ $? -ne 0 ]
	then
		echo "Failed to download the rootfs, aborting."
		return 1
	fi

	# install extra packages
	for pkg in ${extrapackages}
	do
		MROOT=${cache}/partial-${arch} mage install ${pkg}
		if [ $? -ne 0 ]
		then
			echo "Failed to install package ${pkg}, aborting."
			return 1
		fi
	done

	mv "${cache}/partial-${arch}" "${cache}/rootfs-${arch}"
	echo "Download complete."

	return 0
}

copy_magellan()
{
	local cache="$1"
	local arch="$2"
	local rootfs="$3"

	# make a local copy of the minimagellan
	echo "Copying rootfs to ${rootfs}..."
	cp -a ${cache}/rootfs-${arch} ${rootfs} || return 1
	return 0
}

install_magellan()
{
	local cache="/var/cache/lxc/magellan"
	local rootfs="$1"

	mkdir -p /var/lock/subsys/
	(
		flock -n -x 200
		if [ $? -ne 0 ]
		then
			echo "Cache repository is busy."
			return 1
		fi

		arch=$(uname -m)
		echo "Checking cache download in ${cache}/rootfs-${arch} ... "
		if [ ! -e "${cache}/rootfs-${arch}" ]
		then
			download_magellan "${cache}" "${arch}"
			if [ $? -ne 0 ]
			then
				echo "Failed to download 'magellan base'"
				return 1
			fi
		fi

		install -d $(dirname ${rootfs})
		copy_magellan "${cache}" "${arch}" "${rootfs}"
		if [ $? -ne 0 ]; then
			echo "Failed to copy rootfs"
			return 1
		fi

		return 0

	) 200>/var/lock/subsys/lxc

	return $?
}

copy_configuration()
{
	local path="$1"
	local rootfs="$2"
	local name="$3"

	cat <<EOF >> ${path}/config
lxc.tty = 4
lxc.pts = 1024
lxc.rootfs = ${rootfs}
lxc.cgroup.devices.deny = a
# /dev/null and zero
lxc.cgroup.devices.allow = c 1:3 rwm
lxc.cgroup.devices.allow = c 1:5 rwm
# consoles
lxc.cgroup.devices.allow = c 5:1 rwm
lxc.cgroup.devices.allow = c 5:0 rwm
lxc.cgroup.devices.allow = c 4:0 rwm
lxc.cgroup.devices.allow = c 4:1 rwm
# /dev/{,u}random
lxc.cgroup.devices.allow = c 1:9 rwm
lxc.cgroup.devices.allow = c 1:8 rwm
lxc.cgroup.devices.allow = c 136:* rwm
lxc.cgroup.devices.allow = c 5:2 rwm
# rtc
lxc.cgroup.devices.allow = c 254:0 rwm

# mounts point
lxc.mount.entry=proc ${rootfs}/proc proc nodev,noexec,nosuid 0 0
lxc.mount.entry=devpts ${rootfs}/dev/pts devpts defaults 0 0
lxc.mount.entry=sysfs ${rootfs}/sys sysfs defaults  0 0
EOF

	if [ $? -ne 0 ]
	then
		echo "Failed to add configuration"
		return 1
	fi

	return 0
}

clean()
{
	local cache="/var/cache/lxc/magellan"

	if [ ! -e ${cache} ]
	then
		exit 0
	fi

	# lock, so we won't purge while someone is creating a repository
	(
		flock -n -x 200
		if [ $? != 0 ]; then
			echo "Cache repository is busy."
			exit 1
		fi

		echo -n "Purging the download cache..."
		rm --preserve-root --one-file-system -rf ${cache} && echo "Done." || exit 1
		exit 0
	) 200>/var/lock/subsys/lxc
}

usage()
{
	cat <<EOF
$1 -h|--help -p|--path=<path> --clean
EOF
	return 0
}

options=$(getopt -o hp:n:c -l help,path:,name:,clean -- "$@")
if [ $? -ne 0 ]
then
	usage $(basename $0)
	exit 1
fi
eval set -- "${options}"

while true
do
	case "$1" in
		-h|--help)	usage $0 && exit 0;;
		-p|--path)	path=$2; shift 2;;
		-n|--name)	name=$2; shift 2;;
		-c|--clean)	clean=$2; shift 2;;
		--)		shift 1; break ;;
		*)		break ;;
	esac
done

if [ ! -z "${clean}" -a -z "${path}" ]
then
	clean || exit 1
	exit 0
fi

# sanity checks
[ "$(id -u)" != "0" ] && die "This script should be run as 'root'"
type mage-bootstrap || die "'mage-bootstrap' command is missing"
[ -z "${path}" ] && die "'path' parameter is required"

rootfs=${path}/rootfs

install_magellan ${rootfs} || die "failed to install magellan"
configure_magellan ${rootfs} ${name} || die "failed to configure debian for a container"
copy_configuration ${path} ${rootfs} || die "failed write configuration file"

if [ ! -z ${clean} ]
then
	clean || exit 1
	exit 0
fi