etherpad.conf

<VirtualHost *:80>
    ServerName ETHERPAD_WEB_ADDRESS
    
    ProxyVia On
    ProxyRequests Off
    ProxyPreserveHost on
    
    <Location />
        ProxyPass http://localhost:ETHERPAD_PORT/ retry=0 timeout=30
        ProxyPassReverse http://localhost:ETHERPAD_PORT/
    </Location>
    <Location /socket.io>
        # This is needed to handle the websocket transport through the proxy, since
        # etherpad does not use a specific sub-folder, such as /ws/ to handle this kind of traffic.
        # Taken from https://github.com/ether/etherpad-lite/issues/2318#issuecomment-63548542
        # Thanks to beaugunderson for the semantics
        RewriteEngine On
        RewriteCond %{QUERY_STRING} transport=websocket    [NC]
        RewriteRule /(.*) ws://localhost:ETHERPAD_PORT/socket.io/$1 [P,L]
        ProxyPass http://localhost:ETHERPAD_PORT/socket.io retry=0 timeout=30
        ProxyPassReverse http://localhost:ETHERPAD_PORT/socket.io
    </Location>

    <Proxy *>
      Options FollowSymLinks MultiViews
      AllowOverride All
      Order allow,deny
      allow from all
    </Proxy>
</VirtualHost>