How to import a Python library from a Chroot jail?

Question

Let's say I'm trying to execute some code from a library in a directory, let's call it /home/user/project . In Bash it would go like this:

cd /home/user/project
python -c "from MyLib import DoSth; var = DoSth(); print(var)"

Now my exact situation is a little more complicated. My Python code (including all the installed libraries) lies in a chroot jail. I'm trying to execute the code from outside the jail. I tried the following:

cd /home/user/project
sudo -- chroot $CHROOT_DIR python3 -c "from MyLib import DoSth; var = DoSth(); print(var)"

This prints:

ModuleNotFoundError: No module named 'MyLib'

This is because the current directory inside the jail is just / becuase the previous cd statement was not executed inside the jail. When I tried it like this:

sudo -- chroot $CHROOT_DIR cd /home/user/project; python3 -c "from MyLib import DoSth; var = DoSth(); print(var)"

I got this error instead:

chroot: failed to run command 'cd': No such file or directory

Is there a way to use the library without having to change directories inside the jail? Or at least help me find a way to change directories inside the jail.

EDIT:

What I'm trying to do is the exact opposite of the suggested question . I'm trying to execute the code (which is entirely inside the jail) from outside the jail. The code runs perfectly inside the jail, but not from the outside. /home/user/project is a directory inside the jail.

Answer 1

I managed to do this by running a script containing all the commands I need instead of running separate commands, since cd always fails to run on chroot (even though the directory is inside the jail). Here's the command:

sudo -- chroot $CHROOT_DIR /bin/bash /home/user/myscript

In myscript:

cd /home/user/project
python3 -c "from MyLib import DoSth; var = DoSth(); print(var)"