Canonical, the company behind popular Linux distribution Ubuntu, has published a guide to setting up a cheap computing cluster using Raspberry Pi single-board computers and the Microk8s implementation of Kubernetes — and, more importantly, has gone into considerable detail on why you'd want to do so.
"Why build a Raspberry Pi Microk8s cluster," asks Canonical's Rhys Davies. "The simple answer is to offload computation resources from your main computer to a cute little stack of Raspberry Pis. The longer answer is to give yourself, and your computer, a break to do other things and save time. You can use the cluster for resource allocation or as a separate system.
"For example, if you are a photographer who takes a lot of high-resolution photos, you might find that uploading, stitching, or rendering those photos can prove tedious. Instead, you could offload each photo to a Raspberry Pi. This way you have multiple things working at the same time and can get on with writing a blog about your trip. Similarly, if you’re getting into the YouTube business you might find it takes a while to upload your videos. You have to keep a careful eye on it so that when it’s done you can go back straight away to watch cat videos. With a Raspberry Pi Microk8s cluster, you can offload the upload. It might take a little longer if your cluster isn’t that big, but it frees up some time."
While clusters based on Raspberry Pis are nothing new, Canonical has been working on a guide to doing so using MicroK8s, a slimline variant of Kubernetes: "Kubernetes hasn’t become a buzzword for no reason," Davies writes. "It has a myriad of features and benefits that make it so. Ultimately it comes down to automated efficiency. What happens if a container running a work-load goes down? If traffic to a container is too high? What happens if you have so much to work to do that allocating resources is a waste of time? And what happens if you are dealing with confidential data or you need to protect your workload? Well. Kubernetes solves all of those problems and more."
The full tutorial, which begins with the configuration of at least two Raspberry Pi single board computers and the installation of MicroK8s, can be found on the Ubuntu website now; Davies' blog post, meanwhile, goes into more detail on the why and what you can expect to get out of the process.