Apache Proxy to a back-end server

<VirtualHost *>
 DocumentRoot /var/empty
 ServerName derp.example

 SSLEngine On
 RequestHeader set X-Forwarded-Proto "https"

 AllowEncodedSlashes NoDecode

 ProxyPreserveHost On

 ProxyPass "/" "http://127.0.0.1:3000/" upgrade=websocket
 ProxyPassReverse "/" "https://derp.example/"
 ProxyPassReverse "/" "http://127.0.0.1:3000/"

</VirtualHost>