Bug#880195: Not a bug, a feature (was: apache2: Trying to use ws:// in proxy...)

[Vincent Caron <vcaron@bearstech.com>]

The error message is misleading. It happens if a client try to contact
the proxy entrypoint with the HTTP protocol without requesting an
upgrade to Websocket : only websocket requests can be tunneled to a
websockend endpoint, thus the proxy complains.

Your web application should have a subset of paths which use Websockets
and all other paths with plain HTTP(S). The correct config often boils
down to :

    Proxy /ws  ws://host:port/
    Proxy /    http://host:port/

And DON'T try to test by requesting the /ws URL with curl or your
browser, it will try plain HTTP(S) without asking for websocket upgrade
and Apache will complain with the message this bugreport mentions.