nginx server_name based on $hostname

Question

Based on the Nginx wiki the $hostname variable is set to the machine's hostname as returned by gethostname.

I tried that and although gethostname doesn't work my Debian box it still returns the host correctly. Then I tried to use that variable $hostname to set the server_name, but that didn't work.

Why is that and is there another way I can accomplish that?

server { listen 80; autoindex off; server_name static.$hostname; root /var/www/static; access_log /var/log/nginx/localhost.access.log; location / { index index.html; } error_page 404 /404.html; error_page 500 502 503 504 /50x.html; } 

Answer 1

Most variables in nginx only exist at runtime, not during configuration time.

For this reason, most variables cannot be used with the server_name directive. Since $hostname is a constant value, there's an explicit check for exactly $hostname in the server_name handler.

It only allows for the server_name to be set to $hostname, not static.$hostname. You may be able to patch the source to make it support that feature (ngx_http_core_module.c, look for $hostname), but you can't do it with the existing code.

Answer 2

You should find this works:

server_name static.*; 

Answer 3

To set the server name in Nginx to the virtual machine name, you can use the built-in variable $hostname.

server { listen 443 ssl; server_name $hostname; }