Raspberry Pi 4 Cluster

I originally built this Raspberry Pi Cluster to learn how to use Kubernetes. It's built with 4 Raspberry Pi 4 8gb boards and currently running Kubernetes with MicroK8s on Ubuntu Server 20.04 LTS.

I had been looking for a way to power all 4 with one PSU, instead of 4 separate ones. At first I thought about using some sort of powered USB hub but I don't think I would be able to get consistent power. I've had issues before with BrownOuts. I had seen people use desktop power supplies and convert them to 5v to power multiple Raspberry Pis but I wanted something smaller and I wanted less cables. I already had to have the ethernet cables running to each Pi.

So why not just use the Ethernet cables and ditch everything else? Well that's exactly what I did. Power over Ethernet (PoE) is a technology that passes electric power over a twisted-pair Ethernet cable to powered devices (PD), such as wireless access points, IP cameras, and VoIP phones in addition to the data that cable usually carries. It enables one RJ45 cable to provide both data connection and electric power to PDs instead of having a separate cable for each. But this wouldn't work without having to upgrade each Rasperry Pi first. So I picked up 4 Poe Hats. The PoE HAT allows you to power your Raspberry Pi using Power over Ethernet–enabled networks; for this product to be used, the network it is connected to needs to have power-sourcing equipment installed. So I also picked up a PoE switch, in my case I went with the Zyxel 5 port Gigabit Switch (GS1005HP) due to it's small form factor.

Now the real question, what should I do with it?