Simple, small-scale Kubernetes distributions for the edge

Right-Sized

Production Kubernetes clusters use several physical servers, whether the Kubernetes nodes run directly on the hardware or use a virtualization layer – although not actually needed today. Many articles published about Kubernetes rely on single-node setups for practical examples because it is what application developers primarily use. At the same time, the number of scenarios in which single-node setups also make sense in practical use is increasing. More and more users are equipping edge devices with a simple Kubernetes environment.

On one hand, you can use a central cluster management system such as Open Cluster Manager [1] to manage these devices. On the other hand, you only need to develop and test your applications for a single platform: Kubernetes. A practical example includes merchandise management systems. The components for warehousing, invoicing, and ordering run on the central Kubernetes clusters in the data center, whereas small edge servers with the point-of-sale (POS) application in a Kubernetes container are fine for the in-store POS systems.

More powerful Kubernetes platforms (e.g., Rancher (SUSE) or OpenShift (Red Hat)) are not easy to set up on a single node. Although technically feasible, it makes little sense because full-fledged platforms run several dozen containers themselves. For this reason, various manufacturers offer lightweight Kubernetes distributions that only need a few containers for edge operation.

In this article, I look at three of these distributions: K3s (SUSE), MicroShift (Red Hat), and MicroK8s (Canonical). Of course, you will find other lean distributions, such as Kubernetes in Docker (KinD), Minikube, and k3d, but I do not look at those options here because they are primarily intended for use on developer desktops.