Configure pion port range

[mattyg]

I'm trying to run a conductor from a docker container and I need to be able to limit the range of ports used by pion. It looks like pion supports configuring a min & max port via the SettingEngine, which gets passed into the initial webrtc.NewAPI call.

See https://github.com/pion/webrtc/blob/37c7e3c55136c7699e58d7335eec0488020eb6c4/settingengine.go#L30

The go-rust binding is a bit over my head, but I'm guessing there will need to be some refactoring needed to manually call webrtc.NewAPI as part of setting up tx5-go-pion, so SettingEngine configuration can be passed in, instead of using a static configuration defined in it's init() function.

It would also be nice to specify a demuxed single port which seems possible, but likely more complicated: https://github.com/pion/webrtc/blob/master/examples/ice-single-port/main.go

[neonphog]

Interesting.

We're currently setting up the setting engine in go's static initializer:

tx5/crates/tx5-go-pion-sys/main.go

Lines 115 to 119 in da9a8fd

	func init() {
	webrtc_api = webrtc.NewAPI(webrtc.WithSettingEngine(webrtc.SettingEngine{
	LoggerFactory: customLoggerFactory{},
	}))
	}

We also have a required once function to set up the event emitter callback for the library:

tx5/crates/tx5-go-pion-sys/main.go

Lines 170 to 179 in da9a8fd

	// register the MessageCb that will be invoked for events
	//
	//export OnEvent
	func OnEvent(
	// the callback to invoke
	event_cb C.MessageCb,
	// the user data to forward to the callback
	event_usr unsafe.Pointer,
	) unsafe.Pointer {

I wonder if that should be renamed and made to take config json that could configure the pion settings engine.

[neonphog]

Alternately, we could wrap everything in a settings engine abstraction, and require all further calls be made through that abstraction.

[mattyg]

Okay, I'll see if I can take a stab at it.

Another workaround could be to just statically define an arbitrary min port, and define the max port to min + max_conn_count -- not sure if that would make it any simpler to implement

edit: nevermind it would still require this refactoring to modify setting engine outside of init that doesn't makes sense.

[mattyg]

yeah this is way over my head. Hopefully you have some bandwidth to take this on. Otherwise I'll try to figure out an alternative deployment setup.

[neonphog]

@mattyg - let me know if this works: #55

I'm not really sure how to unit test this.