nginx CORS config

gistfile1.txt

location / {
    # For CORS
    if ($request_method = OPTIONS ) {
        add_header Access-Control-Allow-Origin $http_origin;
        add_header Access-Control-Allow-Methods "GET, OPTIONS";
        add_header Access-Control-Allow-Headers 'Authorization,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,X-CSRF-Token,X-Zendesk-Lotus-Version';
        add_header Access-Control-Allow-Credentials "true";
        add_header Content-Length 0;
        add_header Content-Type "text/plain charset=UTF-8";
        return 204;
    }

    if ($request_method = GET) {
        add_header Access-Control-Allow-Origin $http_origin;
        add_header Access-Control-Allow-Methods "GET, OPTIONS";
        add_header Access-Control-Allow-Headers 'Authorization,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,X-CSRF-Token';
        add_header Access-Control-Allow-Credentials "true";
    }
    proxy_pass        http://localhost:3000;
    proxy_set_header  X-Real-IP  $remote_addr;
    proxy_set_header Host $host;
    proxy_redirect off;
    proxy_max_temp_file_size 0;
}