Mastering Nginx

A Configuration Guide

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Besides a normal string, NGINX will accept a wildcard as a parameter to the

server_name directive:

• The wildcard can replace the subdomain part: *.example.com


• The wildcard can replace the top-level-domain part: http://www.example.*


• A special form will match the subdomain or the domain itself:
  .example.com (matches *.example.com as well as example.com)

A regular expression can also be used as a parameter to server_name by prepending
the name with a tilde (~):

server_name ~^www.example.com$;

server_name ~^www(\d+).example.(com)$;

The latter form is an example using captures, which can later be referenced

(as $1, $2, and so on) in further configuration directives.

NGINX uses the following logic when determining which virtual server should
serve a specific request:

1. Match the IP address and port to the listen directive.


2. Match the Host header field against the server_name directive as a string.


3. Match the Host header field against the server_name directive with a
   wildcard at the beginning of the string.


4. Match the Host header field against the server_name directive with a
   wildcard at the end of the string.


5. Match the Host header field against the server_name directive as a regular
   expression.


6. If all the Host headers match fail, then direct to the listen directive
   marked as default_server.


7. If all the Host headers match fail and there is no default_server,
   direct to the first server with a listen directive that satisfies step 1.