chr_uml.sh

chr_uml.sh (text/plain), 1.98 KB, created by Toralf Förster on 2014-06-15 08:58:46 UTC

#!/bin/bash
#

#	Toralf Förster
#	Hamburg
#	Germany

# set -x

function mountall	{
	#	is this UML image already in use ?
	#
	mount -o loop $ROOTFS $MNT || return 1
	
	mount -t proc	none			$MNT/proc
	mount -o bind	/dev			$MNT/dev
	mount -o bind	/dev/pts		$MNT/dev/pts
	mount -t tmpfs	none			$MNT/dev/shm
	mount -o bind	/etc/portage/patches	$MNT/etc/portage/patches
	mount -o bind	/sys			$MNT/sys
	mount -o bind	/usr/portage		$MNT/usr/portage
	mount -o bind	/usr/local/portage	$MNT/usr/local/portage
	mount -o bind	/var/lib/distfiles	$MNT/var/lib/distfiles
	mount -t tmpfs	none			$MNT/var/tmp/portage
	
	return 0
}


function umountall	{
	umount $MNT/var/tmp/portage
	umount $MNT/var/lib/distfiles
	umount $MNT/usr/local/portage
	umount $MNT/usr/portage
	umount $MNT/sys
	umount $MNT/etc/portage/patches
	umount $MNT/dev/shm
	umount $MNT/dev/pts
	umount $MNT/dev
	umount $MNT/proc
	umount $MNT
}


#############################################################################
#
CMD=""
ROOTFS=""
JUST_UMOUNT=0

while getopts c:r:U opt
do
	case $opt in
	c)	CMD=$OPTARG
		;;
		
	r)	ROOTFS=$OPTARG
		;;

		
	U)	JUST_UMOUNT=1
		;;
		
	*)	echo "Usage : $(basename $0) -r <root fs> [-c <cmd>] [-U]"
		exit 1
		;;
	esac
done

if [[ -z "$(file $ROOTFS 2>/dev/null | grep 'UUID=')" || ! -w $ROOTFS ]]; then
	echo " not a valid root-fs: $ROOTFS or not write-able"
	exit 1
fi

#	we assume different file names for the images
#
NAME=$(basename $ROOTFS)

if [[ "$(whoami)" != "root" ]]; then
	echo " You must be root !"
	exit 2
fi

MNT=/mnt/$NAME
if [[ ! -d $MNT ]]; then
	mkdir $MNT || exit 4
fi

if [[ $JUST_UMOUNT = 1 ]]; then
	umountall
	exit 5
fi

mountpoint -q $MNT
if [[ $? -eq 0 ]]; then
	echo " mount point $MNT is already in use !"
	exit 6
fi

lsof -w $ROOTFS 2>/dev/null | grep -q ^linux
if [[ $? -eq 0 ]]; then
	echo " uml is already running at $ROOTFS !"
	exit 7
fi

mountall || exit 8

if [[ -n "$CMD" ]]; then
	chroot $MNT /bin/bash -c "su - root -c '$CMD'"
else
	chroot $MNT /bin/bash -c "su -"
fi
RC=$?

umountall

exit $RC