How to allow specific IP's to a URL (not directory!) in Nginx

You are trying to return a 404 error for all IP, but the specified? Use the directive "error_page" with "=404" parameter. Sort of ...

location /specificurl {
   root /var/www/site1.com/current;
   allow 123.123.123.123;
   deny all;

   error_page 403 =404 /404.html;

}

http://nginx.org/en/docs/http/ngx_http_core_module.html#error_page

Furthermore, it is possible to change the response code to another, for example:

error_page 404 =200 /empty.gif;

Or something like ...

location /specificurl {
   root /var/www/site1.com/current;
   allow 123.123.123.123;
   deny all;

   error_page 403 = @goaway;

}

location @goaway {
    return 444;
}

I managed to solve it myself, and this is how:

    set $deny_access off;

    if ($remote_addr !~ (123.123.123)) {
            set $deny_access on;
    }
    if ($uri ~ "^/(specificurl)$" ) {
            set $deny_access on$deny_access;
    }
    if ($deny_access = onon) {
            return 444;
    }

In the location block and the following line,

try_files $uri $uri/ /index.php?q=$uri&$args;

So it will be like

location /index.php/admin {
   try_files $uri $uri/ /index.php?q=$uri&$args;
   allow 123.123.13.124;
   deny all;
{

It worked for my case. It may work for you.