nginx.conf

    server {
        listen       81;

        root   /home/dmitry/project/public;

        location / {
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header Host $host;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_redirect off;
            try_files $uri $uri/index.html $uri.html @ruby;
        }

        location @ruby {
          proxy_pass http://192.168.10.101:3000;
        }
    }