nginx rails proxy forward

gistfile1.txt

upstream app {
    server 127.0.0.1:3000;
}

server {
        listen 3003 default_server;

        root /home/david/uniswap_monitor_admin/public;

        server_name _;

        try_files $uri/index.html $uri @app;

        location @app {
                proxy_pass http://app;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header Host $http_host;
                proxy_redirect off;
        }

}