#!/bin/sh

# Copyright (C) 2007 Google Inc.
#
# This program 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 program 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 Street, Fifth Floor, Boston, MA
# 02110-1301, USA.

set -e

# Customize this if you need another mirror, or set to empty to get the
# node's sources.list
MIRROR="http://ftp.debian.org/debian"
DPKG_ARCH="`dpkg --print-architecture`"
CACHE_FILE="cache-${DPKG_ARCH}.tar"

TEMP=`getopt -o i:b:s: -n '$0' -- "$@"`

if [ $? != 0 ] ; then echo "Terminating..." >&2 ; exit 1 ; fi

# Note the quotes around `$TEMP': they are essential!
eval set -- "$TEMP"

while true; do 
	case "$1" in
		-i) instance=$2; shift 2;;

		-b) blockdev=$2; shift 2;;

		-s) swapdev=$2; shift 2;;

		--) shift; break;;

		*)  echo "Internal error!"; exit 1;;
	esac
done
if [ -z "$instance" -o -z "$blockdev" -o -z "$swapdev" ]; then
	echo "Missing -i or -b or -s argument!"
	exit 1
fi

mkswap $swapdev
mke2fs -Fjq $blockdev
TMPDIR=`mktemp -d` || exit 1
trap "umount $TMPDIR; rmdir $TMPDIR" EXIT
mount $blockdev $TMPDIR

# remove the cache file if it's old (> 2 weeks) and writable by the owner (the
# default due to the standard umask)
if [ -f "$CACHE_FILE" ]; then
	find "$CACHE_FILE" -perm -0200 -daystart -mtime +14 -print0 | \
		xargs -r0 rm -f
fi

if [ -f "$CACHE_FILE" ]; then
	tar xf "$CACHE_FILE" -C $TMPDIR
else
	# On i386, we need the xen-specific library
	if [ "$DPKG_ARCH" = "i386" ]; then
		EXTRAPKG="linux-image-xen-686 libc6-xen"
	elif [ "$DPKG_ARCH" = "amd64" ]; then
		EXTRAPKG="linux-image-xen-amd64"
	fi

	debootstrap --include="$EXTRAPKG" etch $TMPDIR $MIRROR

	# remove the downloaded debs, as they are no longer needed
	find "$TMPDIR/var/cache/apt/archives" -type f -name '*.deb' -print0 | \
		xargs -r0 rm -f

	# remove the persistent-net rules, otherwise it will remember the node's
	# interfaces as eth0, eth1, ...

	rm -f "$TMPDIR/etc/udev/rules.d/z25_persistent-net.rules"

	if [ ! -e no_cache ]; then
		TMP_CACHE=`mktemp "${CACHE_FILE}.XXXXXX"`
		tar cf "$TMP_CACHE" -C $TMPDIR .
		mv -f "$TMP_CACHE" "$CACHE_FILE"
	fi
fi

cp -p /etc/hosts $TMPDIR/etc/hosts
cp -p /etc/resolv.conf $TMPDIR/etc/resolv.conf
echo $instance > $TMPDIR/etc/hostname
echo $instance > $TMPDIR/etc/mailname

cat > $TMPDIR/etc/fstab <<EOF
# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
/dev/sda        /               ext3    defaults        0       1
/dev/sdb        swap            swap    defaults        0       0
proc            /proc           proc    defaults        0       0
EOF

cat > $TMPDIR/etc/network/interfaces <<EOF
auto lo
iface lo inet loopback
EOF

umount $TMPDIR
rmdir $TMPDIR
trap - EXIT

exit 0