#!/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.

set -xe

: ${VG=/dev/dink}
SUITE=$1
ARCH=$2
CHROOT="${SUITE}-${ARCH}-sbuild"
DEVICE="$VG/$CHROOT"
SIZE=2G

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

if fgrep -x "[$CHROOT]" /etc/schroot/schroot.conf; then
	echo "Chroot $CHROOT already exists." >&2
	exit 1
fi

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

DATA="$(dirname "$0")"

SOURCESD="$DATA/sources.list.d"
if [ -e "$SOURCESD/debian/$SUITE.list" ]; then
	SOURCES="$SOURCESD/debian/$SUITE.list"
	MIRROR=http://localhost:9999/debian
elif [ -e "$SOURCESD/ubuntu/$SUITE.list" ]; then
	SOURCES="$SOURCESD/ubuntu/$SUITE.list"
	MIRROR=http://localhost:9999/ubuntu
else
	echo "Unrecognized suite $SUITE." >&2
	exit 1
fi

lvcreate --size "$SIZE" --name "$CHROOT" "$VG"
mkfs.ext3 "$DEVICE"
tune2fs -c 0 -i 0 "$DEVICE"

exittrap() { umount "$TARGET" || :; rmdir "$TARGET" || :; }
TARGET=$(mktemp -dt make-chroot.XXXXXX)
mount "$DEVICE" "$TARGET"
debootstrap --variant=buildd --include=apt-utils,gnupg,build-essential,fakeroot --foreign --arch "$ARCH" "$SUITE" "$TARGET" "$MIRROR"
install -m a=rx,u+w "$DATA/policy-rc.d" "$TARGET/usr/sbin/"
umount "$TARGET"
rmdir "$TARGET"
exittrap() { :; }

cat >> /etc/schroot/schroot.conf <<EOF

[$CHROOT]
type=lvm-snapshot
description=$CHROOT
priority=3
groups=root,sbuild
root-groups=root,sbuild
source-groups=root
device=$DEVICE
mount-options=-o noatime
lvm-snapshot-options=--size $SIZE
personality=$PERSONALITY
run-setup-scripts=true
run-exec-scripts=true
EOF

schroot --chroot="${CHROOT}-source" --directory=/ -- /bin/sh -e - \
    8< "$SOURCES" \
    9< "$DATA/debathena-archive.asc" \
    <<EOF
/debootstrap/debootstrap --second-stage
debconf-set-selections <<SELECTIONS
debconf	debconf/frontend	select	Noninteractive
SELECTIONS
cat <&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