#!/bin/bash -e

# Default location for a repository.
repo=http://qafiler.boston.redhat.com/redhat/rawhide-i386/
# Default filesystem size (megabytes).
fssize=1024
# Default root device (emulated, of course).
rootdev=/dev/hda1

if test $# -lt 1; then
	echo Usage: `basename $0` imagename repo-url "[fssize(MB)]" "[rootdev]" "[package ...]"
	echo Default repo value is "$repo"
	echo Default fssize is ${fssize}MB "(can be increased later with resize2fs)."
	echo Default rootdev is ${rootdev}.
	echo Package groups can be specified in the form \"@Group\".
	exit 1
fi
name=${1}
repo=${2:-"$repo"}
fssize=${3:-"$fssize"}
rootdev=${4:-"$rootdev"}
if test $# -le 4 ; then
	shift $#
else
	shift 4
fi
: echo Name: $name
: echo Repository: $repo
: echo FS Size: ${fssize}MB
: echo Root Device: $rootdev
: echo Other packages and groups: $*
: sleep 2
# I have no idea if SELinux works on xenU kernels.
selinux=disabled
policy=targeted

# Use the current directory as a chroot parent.
root=`pwd`/${name}.chroot

# Be ready to clean up if the user breaks out.  Clean up any previously-canceled
# runs if we find them.
unmount() {
	set +e
	umount ${root}/sys
	umount ${root}/proc
	umount ${root}/dev
	umount ${root}
	rmdir ${root}
}
if test -d ${root} ; then
	unmount
fi
trap unmount EXIT

# Create the image of the root filesystem if needed.
if ! test -s ${name}.img ; then
	dd if=/dev/zero bs=1M seek=${fssize:-1024} count=1 of=${name}.img
	mke2fs -j -F ${name}.img
fi

# Mount the filesystem, and borrow /dev, /proc, and /sys.
test -d ${root} || mkdir ${root}
mount -o loop -t ext3 ${name}.img ${root} || exit
test -d ${root}/dev  || mkdir ${root}/dev
test -d ${root}/proc || mkdir ${root}/proc
test -d ${root}/sys  || mkdir ${root}/sys
mount --bind /dev  ${root}/dev
mount --bind /proc ${root}/proc
mount --bind /sys  ${root}/sys

# Point yum at the repository which we want to use.
cat > ${root}/yum.conf << EOF
[main]
debuglevel=1
assumeyes=1
[default]
name=Default (i386)
baseurl=$repo
gpgcheck=0
EOF

# Ouch, yum.  Seriously, I really don't want you using repos from repos.d.
# But this probably doesn't work anyway.
yumflags=
for repo in /etc/yum.repos.d/* ; do
	if grep -q '^enabled=1$' $repo ; then
		repo=`grep '^\[.*\]$' $repo | sed -r 's,\[(.*)\],\1,g'`
		yumflags="$yumflags --disablerepo=$repo"
	fi
done

# Create fstab.
mkdir -p ${root}/etc/sysconfig
cat > ${root}/etc/fstab << EOF
${rootdev}       /        ext3   defaults       1 1
/dev/devpts     /dev/pts devpts gid=5,mode=620 0 0
/dev/shm        /dev/shm tmpfs  defaults       0 0
/dev/proc       /proc    proc   defaults       0 0
/dev/sys        /sys     sysfs  defaults       0 0
EOF

# Create an RPM database.
test -s ${root}/var/lib/rpm/Packages || rpm --root ${root} --initdb
# Install a base system.
yum -c ${root}/yum.conf $yumflags --installroot=${root} groupinstall Base
# Install a xenU kernel (we need it) and xen runtime stuff.
yum -c ${root}/yum.conf $yumflags --installroot=${root} install \
	kernel-xenU xen yum netconfig
# Install anything else the caller requested.
while test $# -gt 0 ; do
case "$1" in
@*) yum -c ${root}/yum.conf $yumflags --installroot=${root} groupinstall "${1#@}" ;;
*) yum -c ${root}/yum.conf $yumflags --installroot=${root} install "$1" ;;
esac
shift
done
# Clean up caches -- they may never be used again.
yum -c ${root}/yum.conf $yumflags --installroot=${root} clean all

# Mark that networking should be enabled, and create a basic file describing
# eth0, and leave it at that.  We can run "setup" to change things later.
cat > ${root}/etc/sysconfig/network << EOF
NETWORKING=yes
EOF
cat > $root/etc/hosts << EOF
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1	localhost.localdomain	localhost
EOF
cat > $root/etc/sysconfig/network-scripts/ifcfg-eth0 << EOF
DEVICE=eth0
EOF

# Maybe we'll record a MAC somewhere at some point.
randommac=`dd if=/dev/urandom bs=1 count=6 2> /dev/null | \
	   od -t x1 -An | sed -e s,^\ ,, -e s,\ ,:,g`

# Set up the locale.
cat > ${root}/etc/sysconfig/i18n << EOF
LANG=${LANG:-en_US.UTF-8}
EOF

# Set up the SELinux configuration.
cat > ${root}/etc/sysconfig/selinux << EOF
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#       enforcing - SELinux security policy is enforced.
#       permissive - SELinux prints warnings instead of enforcing.
#       disabled - SELinux is fully disabled.
SELINUX=${selinux:-disabled}
# SELINUXTYPE= type of policy in use. Possible values are:
#       targeted - Only targeted network daemons are protected.
#       strict - Full SELinux protection.
SELINUXTYPE=${policy:-targeted}
EOF
if test -n "$selinux" ; then
	if test "$selinux" != disabled ; then
		touch ${root}/.autorelabel
	fi
fi

# Create a minimally-usable /dev, enough to be useful until udev is started.
umount ${root}/dev
chroot ${root} /sbin/MAKEDEV -x \
	`basename $rootdev` `echo $rootdev | sed s,'[[:digit:]]*$',,g` \
	core \
	console \
	fd \
	full \
	mem \
	nfsd \
	null \
	port \
	ramdisk \
	random \
	stderr \
	stderr \
	stdin \
	stdin \
	stdout \
	stdout \
	tty \
	tty1 \
	tty2 \
	tty3 \
	tty4 \
	tty5 \
	tty6 \
	tty7 \
	tty8 \
	urandom \
	X0R \
	zero

# Add the repository which we used to install the image to its configuration.
cat >> ${root}/etc/yum.conf << EOF
[default]
name=Default (i386)
baseurl=$repo
EOF

# These don't work, at least for me, at least for now.
chroot ${root} /sbin/chkconfig --level 0123456 bluetooth off
chroot ${root} /sbin/chkconfig --level 0123456 gpm off
chroot ${root} /sbin/chkconfig --level 0123456 pcmcia off

# Suppress the warning we'd get at the end of this process if /dev wasn't
# still mounted.
mount --bind /dev  ${root}/dev