A while back, I read this post by Scott Hanselman about his project to set up a Raspberry Pi cluster. More recently, I stumbled upon the very cool Cluster HAT add-on for the Raspberry Pi. In a nutshell, its a simple HAT that allows adding four Pi Zeros all connected to the main controller Pi via USB Gadget mode. The Zeros can either piggyback on the controllers network connection in bridged or NAT mode, or use wireless to connect independently to the network if using Zero W’s.
At the time, there was no availability to buy Cluster HATs that could ship to the US reasonably, so I shelved the idea. Recently, the minor revision Cluster HAT v2.3 was released, and with it I was able to find a full kit, with four Pi Zero W’s, the HAT, and the necessary microSD cards for a good price on PiShop.us. To boot, they had a nice case available for only $16 more.
I decided to go for it, and ordered the kit and the case, since I already had a Pi 3B+ at home that wasn’t getting much use.
Once i received the shipment, the assembly was fairly straightforward using this guide. The case included all the necessary risers to add the HAT and nicely place the combination of the controllers and Zero’s. Included are some clear light tubes to bring the indicator lights for the HAT to the surface of the case. after removing the surface tape as needed, i had to do some gentle sanding on a few rough corners to make them slide into place. The final product was a nice little cluster of Pis.
Next post, I’ll outline the steps I used to getting basic software and control running, and following that I’ll explore my attempts at getting Kubernetes up and running.