How does haproxy get the user's real IP sent from nginx?

Question

The architecture mode is nginx -> haproxy -> apache

How does haproxy get the real IP passed by nginx?

Answer 1

Of course nginx adds a field to the http request header and forwards the real address to the backend. What are you thinking about?

Answer 2

It’s very simple. Just add the following command in the configuration options
option forwardfor except 127.0.0.1