Shared filesystem support

I'd like to run an external script file (.sh or .py) by creating a new machine.

command: python /app/script.py

But new machines have a separate & isolated filesystem, so they can't find it.
Is it possible to share files / make files accessible by new machines?

The issue does not name any files, tests, or entry points. Start by tracing how new machines are created and how their filesystems are isolated; determine the supported approach for making /app/script.py or other external script files accessible, then verify that a newly created machine can run the requested command.

Written by the indexing model from the issue text.