Mask / rewrite SERVER_NAME for fastcgi depending on server_name directive - php

Question

I have a PHP website that uses subdomains for each user.
I want to be able to internally route cname.otherdomain.com to otherdomain.domain.com and pass this to PHP.
Currently I have this
server {
listen 80;
server_name cname.otherdomain.com;
rewrite ^ $scheme://otherdomain.domain.com$request_uri;
}
server {
listen 80 default_server;
server_name ~^(?<subdomain>[a-z\_\-\.]+)?\.?domain\.com$ "";
root g:/www;
index index.php;
#error_log /var/log/nginx/debug.log debug;
location ~ (?:application|modules|system) {
deny all;
}
location / {
try_files $uri $uri/ /index.php$request_uri;
}
location ^~ /index.php {
fastcgi_split_path_info ^(.+\.php)(/.+)$;
fastcgi_index index.php;
include fastcgi_params;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_param PATH_INFO $fastcgi_path_info;
fastcgi_param SERVER_NAME $http_host;
fastcgi_pass 127.0.0.1:9999;
}
}

Answer 1

If you want to hide this from the user, you need to keep it within a single server block. You could create a server block which captures the subdomain and reuses it with the fastcgi location block:
server {
server_name ~^cname\.(?<subdomain>.+)\.com$;
...
location ... {
fastcgi_param SERVER_NAME $subdomain.domain.com;
}
}
server {
listen 80 default_server;
...
}
Large amounts of duplication within nginx configuration files can be managed with include statements.