How to allow access via CORS to multiple domains within nginx

Question

I was having some issues getting SVGs to load on my website if you were viewing website.com instead of www.website.com. The website is on an nginx server, so I added this, a

Answer 1

Here is a solution that uses map.

This setup allows you to make requests to any subdomain and any port on my-domain.com.

map $http_origin $allow_origin {
    ~^https?://(.*\.)?my-domain.com(:\d+)?$ $http_origin;
    # NGINX won't set empty string headers, so if no match, header is unset.
    default "";
}

server {
    listen 80 default_server;
    server_name _;
    add_header 'Access-Control-Allow-Origin' $allow_origin;
    # ...
}

http://nginx.org/en/docs/http/ngx_http_map_module.html

There are some unexpected things that occur when using if inside location blocks in NGINX. It's not recommended. https://www.nginx.com/resources/wiki/start/topics/depth/ifisevil/ and https://agentzh.blogspot.com/2011/03/how-nginx-location-if-works.html