Using http and mqtt together in a single threaded python app

Question

I am a noob to web and mqtt programming, I am working on a python application that uses mqtt (via hivemq or rabbitmq broker) and also needs to implement http rest api for clients.

I realized using python bottle framework is pretty easy to provide a simple http server, however both bottle and mqtt have their event loop, how do I combine these 2 event loop, I want to have a single threaded app to avoid complexity.

Answer 1

I'm not familiar with bottle but a quick look at the docs it doesn't look like there is any other way to start it's event loop apart from with the run() function.

Paho provides a loop_start() which will kick off it's own background thread to run the MQTT network event loop.

Given there looks to be no way to run the bottle loop manually I would suggest calling loop_start() before run() and letting the app run on 2 separate threads as there is no way to combine them and you probably wouldn't want to anyway.

The only thing to be careful of will be if MQTT subscriptions update data that the REST service is sending out, but as long as are not streaming large volumes of data that is unlikely to be an issue.