Single-node Kubernetes on Raspberry Pi

System Administration, Technology,

I’ve recently got a Raspberry Pi 4 Model B 8GB. I wanted to have one just to try running Kubernetes on Raspberry Pi. Most resources on the web seem to be for a huge cluster with a dozen nodes but I wanted to do it with a single node.

Picture of raspberry pi 4 with black case running
Raspberry Pi 4 Model B in its case

Operating system

As the operating system I chose  Ubuntu because of its Pi support even though I prefer Red Hat based distros.

Upstream choice

I initially tried mikrok8s because it’s promoted on Ubuntu motd but had some issues with it. I don’t remember exactly but it might be because of storage. Also official Mikrok8s tutorial for installing on Raspberry Pi requires minimum 2 cluster nodes.

I ended up using minikube as it’s more for single node clusters. I wasn’t sure how good it would work on Raspberry Pi but I’ve been using it for 5 months.

Setup process

Install Ubuntu server for Raspberry Pi

Install Ubuntu server for Raspberry Pi by following the official guide: https://ubuntu.com/tutorials/how-to-install-ubuntu-on-your-raspberry-pi#1-overview

Note: You should install arm64 version of Ubuntu as steps below are also for arm64

Install docker

Follow the official Docker guide to install docker on ubuntu for arm64: https://docs.docker.com/engine/install/ubuntu/

Install minikube

Install the latest minikube binary using the following commands:

# Get the latest minikube binary for arm64
wget -O minikube_arm64.deb https://storage.googleapis.com/minikube/releases/latest/minikube_latest_arm64.deb
sudo dpkg -i minikube_arm64.deb

Setup the cluster

On first time the cluster is started it will be set up. I used “none” driver with minikube which uses docker. You’ll also need to specify kubelet.resolv-conf on newer ubuntu versions for CoreDNS to work.

Setup/start the cluster using this command:

minikube start --driver=none --extra-config=kubelet.resolv-conf=/run/systemd/resolve/resolv.conf

For subsequent starts you don’t need to provide any arguments and you can just use the following:

minikube start

Enable minikube storage addons

To be able to have any kind of persistent storage you need to enable storage addons using minikube.

Use the following commands:

minikube addons enable storage-provisioner
minikube addons enable default-storageclass

Last thoughts on running Kubernetes on Raspberry Pi

For Kubernetes experiments, Raspberry Pi is great as it is cheap to acquire and run. Considering its low clock speed it may not be the best choice for single-threaded applications even in a large cluster. As the space It uses is minimal it’s easy to store. For development it’s not as easy to work with since most tools work with local clusters.

Another thing to mention I discovered a lack of container images for arm architecture. I imagine it’ll get better because of Apple’s arm based M series chips.

I’ll keep running minikube on my Raspberry Pi and do more Kubernetes experiments on it.

Links

Related posts

2 thoughts on “Single-node Kubernetes on Raspberry Pi”

Leave a Reply

Your email address will not be published. Required fields are marked *