Am 02.04.19 um 09:50 schrieb Chris Withers:

On 02/04/2019 08:25, Tobias Oberstein wrote:

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https://github.com/crossbario/autobahn-python/blob/master/examples/twisted/w...

Any way to get rid of the ugly duplication between the url in line 69 and the endpoint on line 72?

I seem to remember that ends up happening with or without ClientService.

I am aware, but no, it's designed like this, because WebSocket requires a HTTP URL (with potentially path components, query parameters etc) in the opening handshake while the _transport_ does not necessarily have that.

Autobahn allows you to run WebSocket over basically everything that is a bidirectional byte pipe: TCP of course, but also Unix domain socket, pipes, Tor onion services (via https://github.com/meejah/txtorcon) and even serial ports!

Right, but correct me if I'm wrong, my understanding is that URL stands for Univeral Resource Locator and URLs can encode all of the things you

WebSocket needs a _HTTP_ URL an URL from the HTTP scheme cannot encode eg a Unix domain socket path or a serial port one could certainly come with with other/different non-HTTP URL schemes .. and in some way, Autobahn WAMP machinery has sth in that direction: eg WAMP can be run not only over WebSocket, but also RawSocket, which is a WAMP-specific transport (above byte-level, at the framing level), that is simpler than WebSocket, and for that we using (non-standard) URLs like rs://host:port rss://host:port fwiw, WAMP is a protocol with a clear-cut, rigorous and decoupled layering: - bidirectional reliable byte level transport (tcp, uds, pipes, ..) - message framing (websocket, rawsocket, ..) - serialization (json, cbor, flatbuffers, ..) and Autobahn and Crossbar.io support _every_ combination of those layers (dozens) to run WAMP

describe. They certainly contain the host and port, so shouldn't there be a graceful way to specify a URL once and have everything that needs that info or a subset of it get it from there?

a (fully qualified) HTTP URL of course encodes a host and port, but that only covers transports that have those notions

(This isn't necessarily aimed at AutoBahn, seems to be something common in Twisted...)

things look only "simple" when leaving out details;) anyways: this is now OT to the original issue I would think ..

Chris

Chris Withers writes:

Not sure I follow, I specify ws:// and things work. What am I missing? (I know the initial protocol is http and that's "upgraded" into websocket, but the url is still ws:// or wss://, right?)

What Tobias is getting at, I think, is that your URL could be wss://example.com/ws but the endpoint could be a unix-socket at /var/run/foo Now, that said, some of the APIs do allow you to shortcut this in the case when your endpoint will be the same as the host in the URI. Compare these two "Component" examples; the first uses the "long form" way to specify the URL + transport and the second is just a string: https://github.com/crossbario/autobahn-python/blob/master/examples/twisted/w... https://github.com/crossbario/autobahn-python/blob/master/examples/twisted/w...

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fwiw, WAMP is a protocol with a clear-cut, rigorous and decoupled layering:

Do browsers speak WAMP?

Yes. See Autobahn-JS

Do firewalls get upset with it?

No. WAMP connections are usually "outbound" style connections to the router, so most firewall configurations will be fine with this. -- meejah