main.py

"""
Main entrypoint to the webserver.

Some notes:

- Nixpacks triggers a python build when a main.py is present, do not change the name of this file.
- When running fastapi in dev mode, it adds PWD to PYTHONPATH. In production, this is not the case, which is why we need to do it ourselves here
- The __name__ guard ensures that `fastapi dev` can still consume this file and `python main.py` is only executed in production
- Fastapi's cli tooling is in a separate repo. We've modeled our uvicorn invocation after theirs.
  https://github.com/fastapi/fastapi-cli/blob/9a4741816dc288bbd931e693166117d98ee14dea/src/fastapi_cli/cli.py#L162-L171
- Customizing which files are watched for autoreload is challenging (no excludes). https://github.com/fastapi/fastapi/discussions/2863
- The integration tests also run a server. If we make major updates here, we need to manually adjust that command.
"""

import os
import sys

# assume PYTHONSAFE=1, add current directory so we can import `app`
sys.path.append(os.path.dirname(__file__))

# uvicorn will "rerun" this file in some way, so although we should be able to throw an exception when this condition
# isn't met that ends up causing issues with how uvicorn is invoked.
if __name__ == "__main__":
    import uvicorn
    from decouple import config

    from app.environments import is_development

    additional_args = {}

    if is_development():
        additional_args = {
            "reload": True,
            "reload_excludes": [
                # git + venv are automatically excluded
                "web/node_modules/*",
                "tmp/*",
                "web/*",
                "tests/*",
            ],
        }

    PORT = config("PORT", cast=int)

    uvicorn.run(
        # a import path is required for dev, so we use that for prod as well
        app="app.server:api_app",
        # bind on all interfaces
        host="0.0.0.0",
        port=PORT,
        # TODO we should tune this and have it pulled from env
        # workers=2,
        # NOTE important to ensure structlog controls logging in production
        log_config=None,
        # a custom access logger is implemted which plays nicely with structlog
        access_log=False,
        **additional_args,
    )