#!/bin/sh

# Usage: make-chroot SUITE ARCH

# Constructs a chroot environment for the Debian/Ubuntu version SUITE
# and architecture ARCH, and sets up schroot configuration for it.
# Assumes an approx cache is running at localhost:9999.

DEBUG=0
BZ2=0
while getopts 'dz' opt; do
    case "$opt" in
	d)
	    DEBUG=1;;
	z)
	    BZ2=1;;
    esac
done
shift $((OPTIND-1))

set -xe

: ${CHROOTDIR=/srv}
: ${MIRRORHOST=localhost:9999}
: ${DATA="$(dirname "$0")"}
SUITE=$1
ARCH=$2
CHROOT="${SUITE}-${ARCH}-sbuild"
FILE="$CHROOTDIR"/"$CHROOT".tar
[ $BZ2 -eq 1 ] && FILE="${FILE}.bz2"
SIZE=4G

exittrap() { :; }
for sig in 1 2 13 15; do trap "exit $(($sig + 128))" $sig; done
trap 'exittrap' EXIT

if fgrep -qxRs "[$CHROOT]" /etc/schroot/schroot.conf /etc/schroot/chroot.d; then
	echo "Chroot $CHROOT already exists." >&2
	exit 1
fi
if [ -e "$FILE" ]; then
	echo "Chroot tarball $FILE already exists." >&2
	exit 1
fi

if [ -d /etc/schroot/chroot.d ]; then
	CONF=/etc/schroot/chroot.d/$CHROOT
else
	CONF=/etc/schroot/schroot.conf
fi

if [ "$ARCH" = "i386" ]; then
	PERSONALITY=linux32
elif [ "$ARCH" = "amd64" ]; then
	PERSONALITY=linux
else
	echo "Unrecognized architecture $ARCH." >&2
	exit 1
fi

SOURCESD="$DATA/sources.list.d"
if [ -e "$SOURCESD/debian/$SUITE.list" ]; then
	SOURCES="$SOURCESD/debian/$SUITE.list"
	MIRROR="http://$MIRRORHOST/debian"
elif [ -e "$SOURCESD/ubuntu/$SUITE.list" ]; then
	SOURCES="$SOURCESD/ubuntu/$SUITE.list"
	MIRROR="http://$MIRRORHOST/ubuntu"
else
	echo "Unrecognized suite $SUITE." >&2
	exit 1
fi

exittrap() { 
    if [ $DEBUG -ne 1 ]; then
	rm -rf "$TMPDIR" || :
    else
	echo "DEBUG MODE: Clean up $TMPDIR by hand!"
    fi
}
TMPDIR=$(mktemp -d /var/tmp/make-chroot.XXXXXX)
TARGET="$TMPDIR/root"
SCRIPTCFG="default/config"
debootstrap --variant=buildd --include=apt,apt-utils,gnupg,build-essential,fakeroot --arch "$ARCH" "$SUITE" "$TARGET" "$MIRROR"
install -m a=rx,u+w "$DATA/policy-rc.d" "$TARGET/usr/sbin/"
mkdir -p "$TARGET/dev/pts"
# /dev/shm is a symlink to /run/shm on modern distros 
# So if it's not a symlink, then mkdir (and fail if it's something
# that's not a symlink or a directory) and we have to use an schroot 
# config that bind-mounts /run/shm instead of /dev/shm
if [ -L "$TARGET/dev/shm" ] &&
   [ "$(readlink "$TARGET/dev/shm")" = "/run/shm" ]; then
    SCRIPTCFG="default-slash-run/config"
else
    mkdir -p "$TARGET/dev/shm"
fi
mkdir -p "$TARGET/afs"
mkdir -p "$TARGET/mit"
TAROPTS="cf"
[ $BZ2 -eq 1 ] && TAROPTS="cjf"
(cd "$TMPDIR" && tar "$TAROPTS" "$FILE" --numeric-owner root)
rm -rf "$TMPDIR"
exittrap() { :; }

! [ -s "$CONF" ] || echo >> "$CONF"
cat >> "$CONF" <<EOF
[$CHROOT]
type=file
description=$CHROOT
groups=root,sbuild
root-groups=root,sbuild
source-groups=root
script-config=$SCRIPTCFG
file=$FILE
location=/root
personality=$PERSONALITY
EOF

schroot --chroot="${CHROOT}-source" --directory=/ -- /bin/sh -xe - \
    8< "$SOURCES" \
    9< "$DATA/debathena-archive.asc" \
    <<EOF
#/debootstrap/debootstrap --second-stage
dpkg-divert --local --rename --add /sbin/initctl
ln -s /bin/true /sbin/initctl
debconf-set-selections <<SELECTIONS
debconf	debconf/frontend	select	Noninteractive
SELECTIONS
sed "s|MIRRORHOST|$MIRRORHOST|" <&8 > /etc/apt/sources.list
! type apt-key >/dev/null || apt-key add - <&9
apt-get -q -y update
apt-get -q -y dist-upgrade
EOF