Support new API Gateway HTTP APIs

Hi there, I’m getting the following error when my app executes in API Gateway (paths shortened for brevity):

Traceback (most recent call last):
  File "/virtualenv/lib/python3.8/site-packages/gunicorn/workers/sync.py", line 134, in handle
    self.handle_request(listener, req, client, addr)
  File "/virtualenv/lib/python3.8/site-packages/gunicorn/workers/sync.py", line 175, in handle_request
    respiter = self.wsgi(environ, resp.start_response)
  File "/virtualenv/lib/python3.8/site-packages/mangum/adapter.py", line 61, in __call__
    raise exc
  File "/virtualenv/lib/python3.8/site-packages/mangum/adapter.py", line 59, in __call__
    response = self.handler(event, context)
  File "/virtualenv/lib/python3.8/site-packages/mangum/adapter.py", line 76, in handler
    response = self.handle_ws(event, context)
  File /virtualenv/lib/python3.8/site-packages/mangum/adapter.py", line 130, in handle_ws
    request_context = event["requestContext"]
KeyError: 'requestContext'

Here is my FastApi app code:

from fastapi import FastAPI

from app.api import router


def get_application(config) -> FastAPI:
    application = FastAPI(
        title=config.PROJECT_NAME, debug=config.DEBUG, version=config.VERSION
    )
    application.include_router(router, prefix=config.API_PREFIX)

    return application

And here is the Mangum adapter:

from mangum import Mangum

from .app import get_application
from .core import config

handler = Mangum(app=get_application(config), enable_lifespan=False)

Also tried running locally with gunicorn, same error. If I run the app normally with uvicorn it works fine.

I’m using the latest version of FastAPI (0.54.1) and Python 3.8 on a Manjaro Linux machine.

So, according to the examples I’ve read, that looks like pretty standard stuff; I looked online but couldn’t find anything (and the issues posted here seems like they are for old versions), am I missing something?

[jordaneremieff]

Released in 0.8.0.

[jordaneremieff]

I’ve merged the PR for this into master, but there are a few things I want to do before the next release (probably this weekend). I’ll leave this open until then.