How to retreive the real ip address of an http request with v2 app with http_service configuration

How To
1

Hi there,

I have a docker image deployed as a v2 app that receives http traffic using the [http_service] configuration. I would like to derive the real ip address of any requests I receive to this app. Currently I am looking at the X-Forwarded-For header and taking the last address in the comma delimited string but I believe this approach depends on whether this traffic is coming through a reverse proxy and probably some other considerations? Is there any documentation or is anyone able to outline what the correct approach is for acheiving this?

Thanks!

2

If the context helps, my hope is to use this derived ip address to apply rate limiting on requests.

3

We provide a Fly-Client-IP header you can use for this purpose: The Fly Runtime Environment · Fly Docs

It’s not actually possible to hit your service port directly, so it’s safe to use this header for an app running behind our proxy.

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4

Ah that’s perfect, thanks for the quick response!

5

In my experience, it’s HTTP_FLY_CLIENT_IP instead.

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