Nginx: wild card subdomain redirect URL to page with request

Question

I am trying to convert:

http://test.example.com/file.php

To either

http://www.example.com/file.php?subdomain=test

or

http://test.example.com/file.php?subdomain=test

Depending on which is simpler to do or faster

This works for the index page but for subfolders and files it gets in a redirect loop.

server {
      listen   80;

      # Make site accessible from http://localhost/
      server_name   ~^[^.]+.example.com$;
      rewrite ^/(.*)/$ /$1 permanent;

      if ($host ~* ^([^.]+).example.com$) {
              set $subdomain $1;
      }
      rewrite ^(.*)$ $1?subdomain=$subdomain last;

      location / {
              root /var/www/example.com;
              index index.html index.php;
      }

      location ~ \.php$ {
              try_files $uri =404;
              root            /var/www/example.com;
              fastcgi_pass    unix:/var/run/php-fpm.sock;
              fastcgi_index   index.php;
              fastcgi_param   SCRIPT_FILENAME $document_root$fastcgi_script
              include         fastcgi_params;
     }
}

Answer 1

I am not quite sure what your objective is - since your example shows two possibilities. The config below (untested) should result in:

http://test.example.com/file.php ==> http://www.example.com/file.php?subdomain=test

It should match any subdomain, and any file name.

server{
    server_name www.example.com;
    root /var/www/example.com;
    index index.html index.php;

    location ~ \.php$ {
        try_files $uri =404;
        fastcgi_pass    unix:/var/run/php-fpm.sock;
        fastcgi_index   index.php;
        fastcgi_param   SCRIPT_FILENAME $document_root$fastcgi_script
        include         fastcgi_params;
    }
}
server {
    server_name  "~^(?<subdomain>.+)\.example\.com$";
    rewrite ^/(.*?)/?$ http://www.example.com/$1?subdomain=$subdomain;
}

Brief explanations:

• static server_names are matched before regexes - so, any request to www.example.com will be handled by the first server block
• root and index directives should be placed under the server block (not location block), if possible
• the listen directive is not needed for port 80
• the second server block uses a named capture to assign the subdomain to a variable
• the rewrite captures everything from the first slash to the last, excluding both (the (.*?) is lazy).

(As an aside, I am really not quite sure what your config is supposed to do with cases like a directory or a static file. Currently, the following should occur (which doesn't seem sensible):

http://test.example.com/file.jpg ==> http://www.example.com/file.jpg?subdomain=test
http://test.example.com/path/to/subfolder/ ==> http://www.example.com/path/to/subfolder?subdomain=test

It looks like your current config does the same. Add a few more examples of what you want and I may be able to update this config to be more relevant).