How to get site (TCPSite or UnixSite) inside route handler

[samthesuperhero]

Hello everybody,

if I run one application, one runner, and set up two sites: on UnixSite and another TCPSite, how can I distinguish from which site the request is coming, from within request handler code?

Case is to allow specific (control) requests only coming from UnixSite. (Unix socket, obviously)

Thank you!!

[kokoc30]

For one UnixSite and one TCPSite, you can distinguish them using the accepted connection's socket family; you don't need a reference to the Site object.

request.get_extra_info('socket') exposes the transport's socket information (aiohttp 3.7+). For example, put this check at the start of a control handler:

import socket
from aiohttp import web

async def control(request: web.Request) -> web.Response:
    sock = request.get_extra_info('socket')
    if sock is None or sock.family != socket.AF_UNIX:
        raise web.HTTPForbidden(text='Unix-socket connections only')

    # Perform the permitted control operation here.
    return web.json_response({'ok': True})

A connection accepted by UnixSite has AF_UNIX; TCP connections use AF_INET or AF_INET6. The None case is rejected as well. This checks the actual transport rather than trusting the HTTP Host header or the request URL. If you later have several Unix listeners, the family check only distinguishes Unix from TCP; it doesn't identify a particular Unix socket.

Since these are control requests, also account for the deployment boundary: a reverse proxy forwarding public traffic to your Unix socket will pass this check. Restrict that routing and the socket's filesystem permissions as appropriate; the socket family alone does not authenticate the originating user.

References: Request.get_extra_info, Transport.get_extra_info, and socket.family.