How to pass url with & symbols to nginx? from php using X-Accel-Redirect?

Question

PHP

Nginx is used to proxy a remote server.
php code:

$url = '/internal_redirect/?url=' .
            'domain.com?test=123&test2=234' .
            '&protocol=https';

        header("X-Accel-Redirect: " . $url);

The problem is in

domain.com?test=123&test2=234

. If you leave it as in the example, then additional variables like arg_test2 will simply be passed, etc. If you use urlencode, then nginx does not automatically decode. How to deal with symbols? and & Preferably without installing additional modules. This is real?

Partial nginx code

location ~* ^/internal_redirect/ {
  internal;

  set $download_url $arg_protocol://$arg_url;

  proxy_pass $download_url;
}

Answer 1

First, just add the prefix /internal_redirect/

$url = '/internal_redirect/http://domain.com/?test=123&test2=234';

header("X-Accel-Redirect: " . $url);

Then we remove this prefix and add everything that is in $args.

location ~ ^/internal_redirect/(?<url>.+) {
    internal;
    
    proxy_pass $url$is_args$args;
}

Answer 2

Everything after the question mark is not part of the url, but parameters. You can, for example, pass them to nginx in separate headers, and attach them to the url inside it. It does not require any exotic modules.