safely run/test a script within a minimal chroot environment with only selected commands available

safe_run.sh

#!/bin/bash
script=$1
shift
args="$@"
CHROOT=$(mktemp -d)
COMMANDS="/bin/bash /bin/echo"
for c in $COMMANDS; do
    mkdir -p $CHROOT$(dirname $c)
    cp -a $c $CHROOT$(dirname $c)
    libs="$libs $(ldd $c | grep '=>' | cut -d' ' -f 3)"
    libs="$libs $(ldd $c | grep ld-linux | cut -d' ' -f 1 | cut -f 2)"
done
libs=$(for l in $libs; do echo $l; done | sort -u)
for l in $libs; do
    mkdir -p $CHROOT$(dirname $l)
    cp -a $l $CHROOT$(dirname $l)
    r=$(realpath $l)
    mkdir -p $CHROOT$(dirname $r)
    cp -a $r $CHROOT$(dirname $r)
done
mkdir -p $CHROOT/bin
cp -a $script $CHROOT/bin
fakeroot fakechroot /usr/sbin/chroot $CHROOT bash -c \
  "LC_ALL=C $(basename $script) $args"
rm -Rf $CHROOT

based on https://www.reddit.com/r/linux4noobs/comments/3e90rr/whats_the_most_minimal_filesystem_i_could_make_to/

requires chroot, fakeroot and fakechroot