#! /bin/sh -e
#
# $Id: qemu-make-debian-root 353 2008-10-16 20:28:22Z aurel32 $
#
# Script to make a debian root image.
#

set -e

which debootstrap >/dev/null || {
    echo "error: missing debootstrap package" >&2
    exit 1
}
which sfdisk >/dev/null || {
    echo "error: missing fdisk package" >&2
    exit 1
}
which mke2fs >/dev/null || {
    echo "error: missing e2fsprogs package" >&2
    exit 1
}

KEEPFS=0
SPARSE=0

while :; do
    case "$1" in
        -k)
            KEEPFS=1
            ;;
        -s)
            SPARSE=1
            ;;
        -ks|-sk)
            KEEPFS=1
            SPARSE=1
            ;;
        *)
            break
            ;;
    esac
    shift
done

if [ $# -lt 4 ]; then
    echo Usage: "$0 [-ks] size-in-MB distrib deburl image [files_to_copy_in_/root]" >&2
    echo "eg $0 150 sid http://proxy:10000/debian qemu" >&2
    echo "-k keep file system          -s sparse image" >&2
    echo "$0 is normally run as root." >&2
    exit 1
fi

SIZE=$1 # In Mib
DISTRO=$2
URL=$3
IMAGE=$4
shift 4

# now files to copy are in "$@".  We don't put them in a variable
# because that would coufuse spaces-in-filenames with
# whitespace-separation.


if [ $SIZE -lt 130 ]; then
    echo 'Size must be at least 130 megabytes (Debian unstable takes 100)' >&2
    exit 1
fi

cleanup()
{
    echo Cleaning up... >&2
    umount -d $TMP_DIR || true
    losetup -d $LOOP || true
    rm -f $IMAGE
}

trap cleanup EXIT

# Create a filesystem: one track for partition table.
if [ "$SPARSE" = "1" ]; then
    truncate -s ${SIZE}M "$IMAGE"
else
    dd bs=1M count=$SIZE if=/dev/zero of=$IMAGE
fi

SECT=63	# first sector of a partition

# Partition so one partition covers entire disk.
echo "$SECT," | sfdisk -uS -L $IMAGE

# Find an unused loop device and set it up.
LOOP=`losetup -f`
losetup -o $(($SECT*512)) $LOOP $IMAGE

# Create filesystem.
mke2fs -q -m1 $LOOP

TMP_DIR="$(mktemp -d /tmp/mount.XXXXXX)" || \
         { echo >&2 "Failed to create temporary directory"; exit 1; }

# Mount it.
mount $LOOP $TMP_DIR

# Do debian install on it.
debootstrap --variant=minbase $DISTRO $TMP_DIR $URL

# Final configuration.
cat > $TMP_DIR/etc/fstab <<EOF
/dev/hda1 / ext2 errors=remount-ro 0 1
proc /proc proc defaults 0 0
EOF

# Console on ttyS0, not tty1, and no other gettys.
sed 's,1:2345:respawn:/sbin/getty 38400 tty1,1:2345:respawn:/sbin/getty 38400 ttyS0,' < $TMP_DIR/etc/inittab | sed 's,^.:23:respawn.*,,' > $TMP_DIR/etc/inittab.new
mv $TMP_DIR/etc/inittab.new $TMP_DIR/etc/inittab

# Set hostname to base of image name.
basename $IMAGE > $TMP_DIR/etc/hostname

# Create /etc/shadow
chroot $TMP_DIR pwconv

# Set root password to "root"
sed 's/^root:[^:]*/root:$1$aybpiIGf$cB7iFDNZvViQtQjEZ5HFQ0/' < $TMP_DIR/etc/shadow > $TMP_DIR/etc/shadow.new
mv $TMP_DIR/etc/shadow.new $TMP_DIR/etc/shadow

# Remove packages we don't need
chroot $TMP_DIR /usr/bin/dpkg --remove console-common console-tools console-data base-config man-db manpages
# Try to remove all libraries: some won't be removable.
chroot $TMP_DIR dpkg --remove `chroot $TMP_DIR dpkg --get-selections | sed -n 's/^\(lib[^ \t]*\)[\t ]*install/\1/p'` 2>/dev/null || true


# Copy wanted files to /root if asked to
if [ $# -gt 0 ]; then
    cp -a "$@" $TMP_DIR/root/
fi
umount -d $TMP_DIR

trap "" EXIT

echo Done.