Unshared jail

unshared.sh

#!/bin/bash
if [ "$1" != "_unshared_" ]; then
    exec unshare -ruim "$0" _unshared_ "$@"
else
    shift
fi

timeout=$1
tempdir=$(mktemp -d)
dirs_to_mount=({/bin,/lib,/lib64,/usr/{bin,lib,local}})
for dir in ${dirs_to_mount[@]}; do
    mkdir -p ${tempdir}${dir}
    mount -o bind,ro ${dir} ${tempdir}${dir}
done

# chroot $tempdir /usr/bin/timeout 5 "$@"
env -i $(which chroot) $tempdir /usr/bin/timeout $timeout ${@:2}

for dir in ${dirs_to_mount[@]}; do
    umount ${tempdir}${dir}
done

rm -rf $tempdir