Add feature to detect socketcand beacon

[faisal-shah]

This implements the client side service discovery for socketcand:
https://github.com/dschanoeh/socketcand/blob/master/doc/protocol.md#service-discovery

Need some feedback on how to enable this option. In the PR, I've proposed a way that makes the happy path as easy as possible ... though it is a breaking change for the SocketCanDaemonBus class.

Happy path:

bus = SocketCanDaemonBus(None) # Auto detect socketcand server, and connect to first available CAN bus

1. If a host address (hostname,port) is provided, it works the same way as before.

2. If a host address (hostname,port) is not provided, it activates detect_beacon(). The user can optionally provide an address to listen for the beacon on a specific interface and port. If not provided, it listens on all interfaces at the default port 42000. If channel is None, it selects the first channel in the channel list provided in the beacon.

[zariiii9003]

Regarding the API, i'd suggest to leave the actual SocketCanDaemonBus class untouched.
The detect_beacon function could work similar to can.detect_available_configs() and return a list of dictionaries like this:

cfg_list: list[AutoDetectedConfig] = detect_beacon()
bus = SocketCanDaemonBus(**cfg_list[0])

A dictionary should contain all necessary keywords to instantiate the SocketCanDaemonBus.

[faisal-shah]

I'll be testing this in a couple different environments, and will report back.

[faisal-shah]

Alright, tested it on both windows and linux. Good to go from my side. Please review for merge.

[faisal-shah]

All review comments addressed.

[zariiii9003]

You should mention it in the docs, or nobody will know about it 😄
https://python-can--1687.org.readthedocs.build/en/1687/interfaces/socketcand.html

[faisal-shah]

You should mention it in the docs, or nobody will know about it 😄 https://python-can--1687.org.readthedocs.build/en/1687/interfaces/socketcand.html

Done.

Edit ... docstring is there. Not familiar with the documentation on this project, and how it's built. Lemee look into it and see if I can make it pop up in the right place. Pointers appreciated in case anyone's looking.

[zariiii9003]

You need to add .. autofunction:: can.interfaces.socketcand.detect_beacon somewhere before you can reference it.

[faisal-shah]

You need to add .. autofunction:: can.interfaces.socketcand.detect_beacon somewhere before you can reference it.

Done. Docs are passing now.

[faisal-shah]

@zariiii9003 I've noticed sometimes tests will spuriously fail. I made an empty commit to trigger the tests and all are passing now. Let me know if any more changes are required to merge this. Appreciate the pointers in working with the doc system.

[zariiii9003]

There are still a few minor issues. I'll merge after you fix these. Thank you for your patience 👍

[faisal-shah]

There are still a few minor issues. I'll merge after you fix these. Thank you for your patience 👍

Hope I got them all. Thanks for your maintainership.

[zariiii9003]

Thank you!

[FedericoSpada]

Hi All,
I've just updated from version 4.3.1 to 4.4.2 and noticed that dongle autodetection went from lasting 500ms to 4,5s. After some tests, I've found that this change is the main reason for the big increase in duration. Isn't there a better way to implement this detection? Perhaps avoiding it altogether if some drivers aren't installed? Or maybe it could be disabled by default and you need to force the search for this particular interface so that old codes will still run fast without having to update the instruction with something like this:

Thanks in advance, greetings.