Docker is a powerful basis for cloud computing especially if you use Docker Swarm's. This tutorial shows how to autoscale Docker images over a cluster of inexpensive Raspberry Pi Zero computers. It's an interesting way to learn about Docker and using Docker Swarms. The example shows autodeployment of Node-RED instances to individual Pi Zero's which is raises interesting ideas in my mind.
A downside to this example is the laborious setup. Each Pi Zero must have a customized boot SD card created. Seems to me that marrying this idea with the "Cluster HAT" hardware might be easier to manage, since you don't create a customized SD card for each machine in the cluster.