github.com/awootton/knotfreeiot (go): Knotfree.net is a tool for creating IOT products. This is the code for a distributed pub/sub system. Supports a minimal subset of MQTT (3.1 and 5) and other convenient formats. Go and kubernetes. It's live at knotfree.net It runs on tokens so there's no signup to use it. 
Keywords: iot|iot-backend|jwt|mqtt|proposal