gistfile1.txt

upstream app {
   server 127.0.0.1:4000 fail_timeout=5s;
}

server {
    listen       80 default_server;
    server_name  _;
    root '/var/app/current/priv/static';


   location /ws {
     proxy_pass http://app/ws;
     proxy_http_version 1.1;
     proxy_set_header Upgrade $http_upgrade;
     proxy_set_header Connection "upgrade";
   }
}