How to implement dynamic redirect control?

Question

Nginx

There are two servers for serving distributions:
download.example.com (nginx->apache)
static.example.com (CDN) You
need to make a "switch" mechanism that will control which of these servers the distribution will be served for downloading. Literally at the level of some php script - a list of distributions and a switch download.example.com/CDN.
The solution in the forehead is to generate a .htaccess file. But I would like to exclude apache from this process.
Which way to look?

Answer 1

As a result, he acted as follows - when the manager enters the web interface and turns on the CDN for one of the distributions, an empty file is written to a certain directory (for example, /cdnenabled) by the mask product-name.trig. Nginx checks the existence of this file, and if it exists, the user is redirected to the CDN when requesting the distribution. Otherwise, nginx gives it to you.
Example nginx config:

...

server {
  listen 80;

  location ~^/en/(.*)/(.*)-setup.exe$ {
    set $product $1;
    set $setup_part $2;

    if (-f /home/www/example.com/public_html/cdnenabled/$product.trig) {
      rewrite ^ http://cdnserver.com/en/$product/$product-setup.exe; #редирект на CDN в случае существования файла
    }

    #Отдать дистрибутив или показать 404.
    try_files /home/www/example.com/public_html/en/$product/$product-setup.exe /home/www/example.com/public_html/404.html;
  }
}

...

Answer 2

What prevents you from going down a completely stupid path, and when you generate a page with a link, immediately substitute the one you need.
Or generate a redirect on the server on the page,
more options are listed
en.wikipedia.org/wiki/URL_redirection