Performing custom actions on uncaught python exceptions

I wanted to make something that sent a request to a webserver whenenever my python application crashed, which would be logged in a database. It's possible to just wrap the main() function in a try: except: block, but that's ugly and after some quick googling I realised there's a nicer way to do this.

Python's sys.excepthook runs whenever there's an uncaught exception, and you can just write your own function to override this.

Here's an example sending the traceback to a server with a http post request, before raising the usual exception.

# exception_handling.py

import sys
import traceback
from types import TracebackType
from typing import Type

import requests


def set_exception_endpoint(app_name: str, url: str) -> None:

    def handle_exception(
        exc_type: Type[BaseException],
        exc_value: BaseException,
        exc_traceback: Optional[TracebackType],
    ) -> None:
        """over-ride sys.excepthook with a requests.post"""
        if issubclass(exc_type, KeyboardInterrupt):
            # probably don't want to be recording an KeyboardInterrupts
            sys.__excepthook__(exc_type, exc_value, exc_traceback)
            return
        traceback_str = "".join(
            traceback.format_exception(exc_type, exc_value, exc_traceback)
        )
        data = {
            "app": app,
            "traceback": traceback_str,
        }
        resp = requests.post(url, json=data, timeout=0.5)
        sys.__excepthook__(exc_type, exc_value, exc_traceback)

    sys.excepthook = handle_exception

This can then be imported and initialised at the top of an application:

from exception_handling import set_exception_endpoint


set_exception_endpoint("my_crashing_app", "http://localhost:5000")


def main():
    # stuff goes here
    pass


if __name__ == "__main__":
    main():

I'm trying this at work where many of my applications run in docker containers on VMs or k8 pods where I don't have much visibility to logs or any crash reports.