Add trusted networks

[b4stien]

Deploying FastAPI in AWS behind an AWS Load Balancer I hit a roadblack to trust the proxy (the Load Balancer): I know its network but not its IPs. Using ProxyHeadersMiddleware as it is, I'd have to know those IPs beforehand to trust them.

Would you be willing to consider a slight modification to ProxyHeadersMiddleware to accept trusted_networks in addition to trusted_hosts?

Attached is some working code of how it would work.

Checklist

• I understand that this PR may be closed in case there was no previous discussion. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.

PS: I've opened a discussion, you can close this PR in the meantime if needed, it'll still reference some code ideas.

[Kludex]

The current implementation works for trusted networks now. :)

[b4stien]

Oh ok, wonderful! Could you provide a ref of the relevant commits implementing it? Or the docs for the feature?

[b4stien]

This is #2468 and #2231, right?

[Kludex]

This is #2468 and #2231, right?

Yes.

[Kludex]

Oh ok, wonderful! Could you provide a ref of the relevant commits implementing it? Or the docs for the feature?

https://www.uvicorn.org/deployment/#proxies-and-forwarded-headers