Hello, I am trying to use Channels 2 to implement an http/websocket application which also handles asynchronous requests from a second source (right now it's messages from an MQTT subscription, but I think the problem is largely independent from the specific protocol). This doesn't seem to be a common use case, and I could not find any indication on how to do that, either in the official Channels documentation or elsewhere
Given that I must handle the contents of the MQTT messages in the same process as the websocket requests, the ideal approach would be to run both the http/websocket and the MQTT protocol handlers in the same process, but I am quite certain I can't do that. My next thought would then be to have a second process for handling the incoming messages and sending them to the main application as events over a channel layer. For the MQTT side, leaving the specific protocol aside, I have seen examples using asgiref.server.StatelessServer (e.g. https://github.com/andrewgodwin/asgigram), but that ends up creating a scope from the event and passing it to an ASGI application instance -- i.e. it handles the events in-process, which is not what I want. Then there's https://github.com/xavierlesa/channels-asgi-mqtt. The code looks a bit messy, and I think it's been written for Channels 1, but the principle seems clear: retrieve the default channel layer and for every incoming message, send an event of a specific type to a channel with a specific name. But then, how do I receive and handle events from the channel in the websocket process? https://channels.readthedocs.io/en/latest/topics/channel_layers.html says that "Messages across channel layers also go to consumers/ASGI application instances, just like events from the client", and https://channels.readthedocs.io/en/latest/topics/worker.html seems to imply that such events are simply available to the main ASGI application -- but that relies on a having a dummy protocol handler (channels.worker.Worker) subscribe to a set of channels and wrap each event in a scope which is then passed to the ASGI application. So, once again that would seem to require a second protocol handler besides the http/websocket one. Am I missing something? Any Ideas, corrections and pointers to relevant documentation and examples are welcome. Thanks in advance, Andrea -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscr...@googlegroups.com. To post to this group, send email to django-users@googlegroups.com. Visit this group at https://groups.google.com/group/django-users. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/fe5328d6-9808-4623-9f49-950955e74704%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
