Nginx: how to set host header to the server chosen (load balancing)

Question

I have a site that works as load balancer. Site A.

I have other sites that only can have one domain. So if i just redirect to them it says host name not found.

So if i manually set header to something then only that site shows up.

How can i set proxy_set_header Host xxxx to server address chosen. This way each rerouting request will have different and appropriate host header.

It won't be a problem if my other 2 sites could work based on url and not host header.

worker_processes 1; error_log logs/error.log; error_log logs/error.log notice; error_log logs/error.log info; error_log logs/error.log debug; pid logs/nginx.pid; events { worker_connections 1024; } http { upstream myapp1 { #server localhost:3333; server www.asd.com:80; } server { listen 80; location / { proxy_set_header Host $upstream_addr; // should become somehow www.asd.com right now this code doesn't work proxy_set_header X-Forwarded-For $remote_addr; proxy_pass http://myapp1; } } } 

Answer 1

You need to set the header to the incoming host variable, as documented here:

proxy_set_header Host $host; 

Answer 2

Answers to this question explain this behaviour and offer workarounds.

Essentially, the header is fixed well before the upstream is selected. If you cannot make all upstreams respond to a single Host: header, you have to fix the upstream at the same time as you set the header.