Nginx example of using CORS

default.conf

upstream mycoolapp {
  server unix:///var/run/puma.sock;
}

server {
  listen                80;
  server_name           www.my-cool-website.com;
    return 301 https://$host$request_uri;
}

server {
  listen                443 ssl;
  server_name           www.my-cool-website.com;
  root                  /app/public;
  ssl_certificate       /shared/certs/ssl.crt;
  ssl_certificate_key   /shared/certs/ssl.key;

  client_max_body_size  20m;


  location / { 
    add_header 'Access-Control-Allow-Origin' '*';   # change this to more strict CDN host. e.g.: 'xxxxxxxxxxxxxx.cloudfront.net'
    add_header 'Access-Control-Allow-Methods' 'GET, OPTIONS';

    proxy_set_header  Host $host;
    proxy_set_header  X-Real-IP $remote_addr;
    proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header  X-Forwarded-Host $server_name;
    proxy_set_header  Client-IP $remote_addr;
    proxy_pass        http://mycoolapp;
  }
 }

example of socket puma application https://github.com/equivalent/dummy-sinatra-puma-socket-docker-app