Proxying a website with Falcon ASGI + httpx

proxy.py

import falcon.asgi
import httpx


class Proxy(object):
    UPSTREAM = 'https://falconframework.org'

    def __init__(self):
        self._client = httpx.AsyncClient()

    async def handle(self, req, resp):
        headers = dict(req.headers, Via='Falcon')
        for name in ('host', 'connection', 'referer'):
            headers.pop(name, None)

        request = httpx.Request(
            req.method, self.UPSTREAM + req.path, headers=headers)
        response = await self._client.send(request, stream=True)

        resp.stream = response.aiter_bytes()
        resp.content_type = response.headers.get(
            'Content-Type', falcon.MEDIA_HTML)
        resp.status = response.status_code

        # See also:
        # https://www.python-httpx.org/async/#streaming-responses
        resp.schedule(response.aclose)


app = falcon.asgi.App()
app.add_sink(Proxy().handle)