k3s is a certified lightweight Kubernetes distribution by Rancher. With a single binary under 100 MB, k3s is perfect for edge computing, IoT, CI environments, and resource-constrained servers. It bundles containerd, Flannel networking, and SQLite (or etcd) in one package. This guide installs k3s on Ubuntu 26.04 LTS.

Tested and valid on:

  • Ubuntu 26.04 LTS

Prerequisites

  • Ubuntu 26.04 LTS with at least 512 MB RAM and 1 CPU
  • A user with sudo privileges
  • Ports 6443 open in the firewall

Step 1 – Install k3s

curl -sfL https://get.k3s.io | sh -

Step 2 – Verify the Installation

sudo systemctl status k3s
sudo k3s kubectl get nodes

Step 3 – Configure kubectl for Your User

mkdir -p ~/.kube
sudo cp /etc/rancher/k3s/k3s.yaml ~/.kube/config
sudo chown $USER:$USER ~/.kube/config
kubectl get nodes

Step 4 – Deploy a Test Application

kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --port=80 --type=NodePort
kubectl get svc nginx

Step 5 – Add Worker Nodes

On the server, get the join token:

sudo cat /var/lib/rancher/k3s/server/node-token

On each worker node:

curl -sfL https://get.k3s.io | K3S_URL=https://SERVER_IP:6443 K3S_TOKEN=NODE_TOKEN sh -

Step 6 – Use Helm with k3s

curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 | bash
helm version

Step 7 – Uninstall k3s

# Server:
/usr/local/bin/k3s-uninstall.sh
# Agent:
/usr/local/bin/k3s-agent-uninstall.sh

Conclusion

k3s is running on Ubuntu 26.04 LTS. It provides the full Kubernetes API with minimal overhead, making it ideal for edge deployments, home labs, and development clusters.