MQTT - based scaler

I'd like to have a scaler listen to an MQTT source and scale up/down based on incoming messages. This would be useful for Kubernetes clusters that run on the edge (for example, in IoT scenarios and in scenarios where k8s is running on underpowered machines)

• Scaler Source: A scaler to support scaling applications based on incoming MQTT messages. Not intended to support bidirectional communications
• How do you want to scale: Based on volume of messages on a particular topic
• Authentication: Two options are username/password auth and advanced (x.509) auth. username/password auth should be sufficient for now, given that you can already place credentials in a secret and pass them into a ScaledObject