Forgive me if this has been covered before, but I didn't see anything while searching.

I have a server setup similar to:

server {
listen 80;
server_name domain.com someotherdomain.com somethirddomain.com;
rewrite "^(.*)$" http://www.domain.com$1 permanent;
}

server {
listen 80;
server_name www.domain.com *.domain.com;
server_name_in_redirect off;

<other stuff>
}

I had some issues with nginx redirecting to *.domain.com when people would omit a trailing / on physical directories in requests, the only fix I was able to ascertain was setting it up as I have mentioned.

At any rate, if a client makes a request that bypasses our loadbalancer directly via wwwX.domain.com, it gets caught by the second server block as intended. The problem however is that $server_name gets set to the first match in the server_name directive (as mentioned in the documentation). My fastcgi_param for SERVER_NAME is set to $server_name (the default).

The problem is that I need the ability to discern that someone is hitting a server directly via $_SERVER['SERVER_NAME'], and under this default configuration I am unable to do so since even direct requests to webservers end up having $server_name set to www.domain.com, rather than what the Host: was set to (wwwX.domain.com).

I understand that there is also the $host variable, but I was not sure what the best practice is as far as reliably duplicating the SERVER_NAME functionality of Apache.

Any help would be appreciated!

Thanks,
-Kyle