nginx websockets

  #this where socket io will be handling the request
  location /socket.io/ {
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
    proxy_pass "http://localhost:8000/socket.io/";
  }

https://medium.com/@ibraheemabukaff/how-to-proxy-websockets-with-nginx-e333a5f0c0bb

JS Websockets

https://www.sitepoint.com/real-time-apps-websockets-server-sent-events/