Wide-open CORS config for nginx

cors-nginx.conf

#
# Wide-open CORS config for nginx
#
location / {

     if ($request_method = 'OPTIONS') {

        add_header 'Access-Control-Allow-Origin' '*';
        
        #
        # Om nom nom cookies
        #

        add_header 'Access-Control-Allow-Credentials' 'true';
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
        
        #
        # Custom headers and headers various browsers *should* be OK with but aren't
        #

        add_header 'Access-Control-Allow-Headers' 'DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
        
        #
        # Tell client that this pre-flight info is valid for 20 days
        #

        add_header 'Access-Control-Max-Age' 1728000;
        add_header 'Content-Type' 'text/plain charset=UTF-8';
        add_header 'Content-Length' 0;

        return 204;
     }

     if ($request_method = 'POST') {

        add_header 'Access-Control-Allow-Origin' '*';
        add_header 'Access-Control-Allow-Credentials' 'true';
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
        add_header 'Access-Control-Allow-Headers' 'DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';

     }

     if ($request_method = 'GET') {

        add_header 'Access-Control-Allow-Origin' '*';
        add_header 'Access-Control-Allow-Credentials' 'true';
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
        add_header 'Access-Control-Allow-Headers' 'DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';

     }

}

So, i've never done anything with Nginx, cors, and have absolutely zero coding knowledge or experience, in a layman's terms, how in the world am i supposed to use any of this? It doesn't seem to work no matter how i do it. I'm using nginx 1.19.2

@DictatorL -- you'll find a file nginx/conf/nginx.conf in your installation that describes how nginx should accept traffic and route it to your application (here are some pre-canned ones you can use https://www.nginx.com/resources/wiki/start/#pre-canned-configurations). This gist shows you a few different examples of how you might setup CORS by using the add_header options, the exact one for you will depend on what you're trying to accomplish, you can learn more at https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS... although as I pointed out above using a wildcard for the origin is not correct, use this instead:

add_header "Access-Control-Allow-Origin" $http_origin;

@DictatorL -- you'll find a file nginx/conf/nginx.conf in your installation that describes how nginx should accept traffic and route it to your application (here are some pre-canned ones you can use https://www.nginx.com/resources/wiki/start/#pre-canned-configurations). This gist shows you a few different examples of how you might setup CORS by using the add_header options, the exact one for you will depend on what you're trying to accomplish, you can learn more at https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS... although as I pointed out above using a wildcard for the origin is not correct, use this instead:

add_header "Access-Control-Allow-Origin" $http_origin;

That worked!

Saved my days. I use:

add_header "Access-Control-Allow-Origin" $http_origin;
add_header 'Access-Control-Allow-Credentials' 'true';
add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS, PUT';

For firefox, i installed this plugin
https://add0n.com/access-control.html?version=0.1.9&type=install

After the nginx config above, I was still getting cors erros.
Just installed this plugin and it works

not working for me, I always get 304 redirects on backend requests

@GromNaN thanks a lot :D
If you use a cache server, you must add a Vary: Origin to the response.

add_header "Access-Control-Allow-Origin" $http_origin;
add_header "Vary" "Origin";

It worked for allhost.my-domain.com

I try this configuration, but it is not working. I have a backend server with my code (laravel app) Do I need to have some configurations?