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bd413f0 Jun 12, 2016
@falconindy @pierres @jcjordyn130
79 lines (62 sloc) 1.99 KB
#!/bin/bash
shopt -s extglob
m4_include(common)
usage() {
cat <<EOF
usage: ${0##*/} chroot-dir [command]
-h Print this help message
-u <user>[:group] Specify non-root user and optional group to use
If 'command' is unspecified, ${0##*/} will launch /bin/bash.
EOF
}
chroot_add_resolv_conf() {
local chrootdir=$1 resolv_conf=$1/etc/resolv.conf
# Handle resolv.conf as a symlink to somewhere else.
if [[ -L $chrootdir/etc/resolv.conf ]]; then
# readlink(1) should always give us *something* since we know at this point
# it's a symlink. For simplicity, ignore the case of nested symlinks.
resolv_conf=$(readlink "$chrootdir/etc/resolv.conf")
if [[ $resolv_conf = /* ]]; then
resolv_conf=$chrootdir$resolv_conf
else
resolv_conf=$chrootdir/etc/$resolv_conf
fi
# ensure file exists to bind mount over
if [[ ! -f $resolv_conf ]]; then
install -Dm644 /dev/null "$resolv_conf" || return 1
fi
elif [[ ! -e $chrootdir/etc/resolv.conf ]]; then
# The chroot might not have a resolv.conf.
return 0
fi
chroot_add_mount /etc/resolv.conf "$resolv_conf" --bind
}
while getopts ':hu:' flag; do
case $flag in
h)
usage
exit 0
;;
u)
userspec=$OPTARG
;;
:)
die '%s: option requires an argument -- '\''%s'\' "${0##*/}" "$OPTARG"
;;
?)
die '%s: invalid option -- '\''%s'\' "${0##*/}" "$OPTARG"
;;
esac
done
shift $(( OPTIND - 1 ))
(( EUID == 0 )) || die 'This script must be run with root privileges'
(( $# )) || die 'No chroot directory specified'
chrootdir=$1
shift
[[ -d $chrootdir ]] || die "Can't create chroot on non-directory %s" "$chrootdir"
chroot_setup "$chrootdir" || die "failed to setup chroot %s" "$chrootdir"
chroot_add_resolv_conf "$chrootdir" || die "failed to setup resolv.conf"
chroot_args=()
[[ $userspec ]] && chroot_args+=(--userspec "$userspec")
chroot_args+=("$chrootdir" "$@")
SHELL=/bin/bash unshare --fork --pid chroot "${chroot_args[@]}"