Unix domain sockets: Extend documentation & support base_url

[gsakkis]

Is your feature request related to a problem?

1. The docs mention briefly how to connect to a server using unix domain dockets but there's no example of how a valid url should look like. In other words, given aiohttp.UnixConnector(path='/path/to/socket'), what's the equivalent url of http://httpbin.org/get?

After some trial and error, here's what doesn't work and what does:

• ❌ get: InvalidUrlClientError
• ❌ /get: InvalidUrlClientError
• ❌ ///get: InvalidUrlClientError
• ❌ //get: 404 not found - the server receives /
• ❌ All the above prepended by explicit unix: scheme
• ✅ //localhost/get (and unix://localhost/get): works
• ✅ //can-be-anything:12345/get: works but should it? Apparently host/port are ignored but they're still required.

2. After eventually finding a url that works, I tried to set a base_url to unix://localhost (or unix://localhost/) so that I can pass just the relative url (get). Sadly this also raises InvalidUrlClientError

Describe the solution you'd like

1. Extend the documentation to show valid unix domain socket urls look like
2. Support base_url for unix domain sockets

Related component

Client

Code of Conduct

• I agree to follow the aio-libs Code of Conduct

[Dreamsorcerer]

Feel free to contribute some improvements, I suspect this is a very underutilised part of the library. A PR with failing tests for base_url would be a great start.