socket-io-apache-proxy.conf

<VirtualHost *:80>
  # suppose you have a SocketIO server running on port 8001
  # the first request uses the HTTP protocol, and its response instructs the client to use WebSockets
  # subsequent requests are supposed to use the WebSocket protocol
  # this is one way to have an Apache proxy the requests to SocketIO
  #
  # not sure if this is suitable for production use
  # my production environment uses AWS Elastic Load Balancers, not Apache
  # my dev and pen-test environments do use Apache, and this is how I make them work
  
  RewriteEngine On
  
  RewriteCond %{REQUEST_URI}  ^/socket.io              [NC]
  RewriteCond %{QUERY_STRING} transport=polling        [NC]
  RewriteRule /(.*)           http://localhost:8001/$1 [P,L]
                                                          
  RewriteCond %{REQUEST_URI}  ^/socket.io              [NC]
  RewriteCond %{QUERY_STRING} transport=websocket      [NC]
  RewriteRule /(.*)           ws://localhost:8001/$1   [P,L]
</VirtualHost>