setup-chroot

#!/bin/bash

INSTANCE=$$
export INSTANCE

state_checks()
{
	test $(id -u) -ne 0 && echo "please run as root" && exit 1
	test ! -e setup-chroot  && echo "This utility must be run in the directory in which it exists." && exit 1
	test "$PWD" == "/" && echo "You have already started the session." && exit 1
	test ! -d var/lib/pkg && ts/bin/install_chroot
}

help()
{
	echo -e "
	This script sets up the environment to work well with build. On it's initial run, it
	will decompress all the packages necessary to develop and build images. It will
	also populate the ts build env with any files that it needs. If the setup is already
	completed, it will only take you into the chroot env for building. You will need to 'exit'
	this env when you are done working in it. It takes the following options.

	-h : Show this help message.
	-i : Install the env only. Don't enter it after-wards.
	-b : Run build after entering chroot and exit after-wards.
	-d : Use an alternate build directory. Default = /ts/5.1
	-o : Options to pass to build. Must be the last option,
	     as anything after it will be passed to build.
	-c : Clean the chroot env.
	-e : Execute a command after entering chroot. Must
	     be the last option, as anything after it will be
	     executed in the chroot, including arguments.

	"
}

get_opts()
{
	until [ -z "$1" ] ; do
		case $1 in
		-i|--install)	install_only=true ;;
		-d|--directory)	shift ; build_dir=$1 ;;
		-b|--build)	build=true ;;
		-h|--help)	help ; exit 255 ;;
		-o|--options)	shift ; build_opts=$@ ; shift $# ;;
		-c|--clean)	unset build ; shift $# ; touch ./CLEAN ;;
		-e|--exec)	shift ; exec_cmd=$@ ; shift $# ;;
		*)		echo "Invalid Argument: $1" ; help ; exit 255 ;;
		esac
		shift
	done
}

first_or_last()
{
	sessions="`ps x -o pid,ppid,comm |grep -e 'setup-chroot' |grep -v grep |grep -v $INSTANCE -c`"
	return $sessions
}

mounted()
{
	if [ "`cat /proc/mounts |grep -e $PWD/$1 -c`" -ne "0" ]; then
		return 0
	else
		return 1
	fi
}

do_mounts()
{
	if ! mounted dev ; then mount --bind /dev dev ; fi
	if ! mounted tmp ; then mount --bind /tmp tmp ; fi
	if ! mounted proc ; then mount -t proc proc proc ; fi
	if ! mounted sys ; then mount -t sysfs none sys ; fi
	if ! mounted dev/pts ; then mount --bind /dev/pts dev/pts ; fi
}

copy_host_essential()
{
	cp -f /etc/resolv.conf etc/resolv.conf
	if [ -e ~/.ssh ]; then
		mkdir -p root
		cp -Prfd ~/.ssh	root/.
	fi
}

launch_chroot()
{
	do_mounts
	if first_or_last; then
		copy_host_essential
	fi
	chroot /$PWD /bin/bash --rcfile ./ts/TS_ENV
	howdiditgo=$?
	if first_or_last ; then
		do_unmounts
		secure_keys
		if [ -e cleanstage2 ] ; then
                	ts/bin/clean_chroot
        	fi
	fi
}

secure_keys()
{
	if [ -e root/.ssh ]; then
		rm -rf root/.ssh
	fi
}

do_unmounts()
{
	for mount in dev/pts dev tmp proc sys ; do
		while mounted $mount ; do
			umount $mount
		done
	done
}

set_cmd()
{
	if [ ! -z "$exec_cmd" ]; then
		echo "$exec_cmd" > BUILD.$INSTANCE
	fi
}

set_build()
{
	if [ "$build" == "true" ] ; then
		if [ -z "$build_dir" ] ; then
			build_dir=/ts/5.1
		fi
		echo "cd $build_dir" > BUILD.$INSTANCE
		echo "./build $build_opts" >> BUILD.$INSTANCE
	fi
}

main()
{
	get_opts $@
	state_checks
	set_build
	set_cmd
	launch_chroot
	if [ -e installed ] ; then
		copy_host_essential
		rm installed
		if [ "$install_only" == "true" ] ; then
			exit 0
		else
			launch_chroot
		fi
	fi
}

main $@
if [ "$howdiditgo" == "0" ] ; then echo -e "\nGoodbye. \n" ; fi
exit 0