Comment 1 for bug 1708188

I'm not clear what the issue is here. The get_highest_client_server_version takes a URL, which should be he naked endpoint of cinder, without any path like "volume" or "volumev3".
It should not be handed the horizon endpoint, that won't work.
The point of the call is that it does not need authentication, so Horizon isn't needed. If the caller needs to call Horizon (and thus have authentication) to get the Cinder endpoint, then everything should be stripped so only the IP:port for cinder is used.