Make it easier to debug functions in IDEs

[yuri-sergiichuk]

Currently, it is super hard to configure the local debug of the functions in PyCharm, moreover, I found it impossible without hacking the cli.py.

Here is a way to do it in PyCharm now:

1. Add main function to the cli.py:

   if __name__ == '__main__':
       cli(sys.argv[1:])

2. Create PyCharm Python config and choose functions_framework\cli.py as a script.
3. Pass required params as Parameters in the configuration, e.g. --port 8088 --signature-type http, etc.
4. Make sure to set the working directory to the project root (so that the functions framework is able to load the entry point function).
5. Run the created configurations and use PyCharm debugger.

What we can to make life easier:

1. Create __main__.py in the functions_framework module and allow running the module as the CLI. Or, add the main function to the cli.py itself, maybe worth having both.
2. Create well-structured documentation about debugging functions locally with popular IDEs (PyCharm, VSCode, others?)

[di]

Thanks for the report!

I'm not that familiar with PyCharm so bear with me: is it not possible to use a command like functions-framework --debug --port 8088 --signature-type http? It has to be some importable Python script?

I think it would be reasonable to add a __main__.py and support python -m functions_framework, just want to make sure I understand the issue here.

[yuri-sergiichuk]

PyCharm has its own debugger that is injected as a sidecar to the module being run with lots of cool functions.

The --debug here enabled Flask's debug mode and Flask has its own debugger. I have not found a way to make them work together. That's why I need a way to run the functions_framework either as a module or as a script so that PyCharm can do its debug-related magic.

[di]

Hi @yuri-sergiichuk, can you try this branch and let me know if it works for you?

You should be able to install it with:

pip install git+https://github.com/googlecloudplatform/functions-framework-python.git@add-main

[yuri-sergiichuk]

Hi @di. Yes, I can run it as a module now and for PyCharm that it enough.

Also, maybe it still worth having the __main__ in the cli.py? I'm not sure how debuggers work in other IDEs, but right now I still cannot run the cli.py directly.

Also, I use pipenv over pip to manage dependencies, so in case it'd be helpful for someone, with pipenv one can install a dependency from a specific branch with:

pipenv install -e git+https://github.com/googlecloudplatform/functions-framework-python.git@add-main#egg=functions-framework

[di]

Great!

Also, maybe it still worth having the __main__ in the cli.py? I'm not sure how debuggers work in other IDEs, but right now I still cannot run the cli.py directly.

This particular file is not meant to be run directly. I renamed it _cli in #31 to make this more clear.

[di]

Released in functions-framework==1.3.0.

[yan-hic]

Hi @di. Yes, I can run it as a module now and for PyCharm that it enough.

@yuri-sergiichuk can you share what you did in Pycharm to make it run in debug i.e. stop at breakpoints ?

[yan-hic]

nvm - found it:

[dibusan]

nvm - found it:

I got it running, but breakpoints are not stopping. Any ideas ?

[dibusan]

Update: removing --debug fixed it. It now stops at breakpoints.