k3s is a lightweight, certified Kubernetes distribution designed to run efficiently on modest hardware, including a single VPS. This guide covers installing a fully working single-node cluster.
Why k3s Instead of Full Kubernetes
k3s strips out rarely-needed components and ships as a single small binary, using far less memory than a standard kubeadm-based install — ideal for a single VPS or small clusters, without sacrificing compatibility with standard Kubernetes tooling (kubectl, Helm charts all work normally).
Prerequisites
- Ubuntu 22.04/24.04 VPS: 2 vCPU, 4 GB RAM minimum
- Root or sudo access
Step 1 — Install k3s
curl -sfL https://get.k3s.io | sh -This single command installs k3s as a systemd service and starts it automatically.
Step 2 — Verify the Node Is Ready
sudo kubectl get nodesShould show one node with status Ready.
Step 3 — Set Up kubectl Access Without sudo
mkdir -p ~/.kube
sudo cp /etc/rancher/k3s/k3s.yaml ~/.kube/config
sudo chown $(id -u):$(id -g) ~/.kube/config
export KUBECONFIG=~/.kube/configAdd the export line to ~/.bashrc to persist it across sessions.
Step 4 — Deploy a Test Application
kubectl create deployment nginx-test --image=nginx
kubectl expose deployment nginx-test --port=80 --type=NodePortStep 5 — Find the Assigned Port and Test
kubectl get svc nginx-testcurl http://localhost:PORT_SHOWN_ABOVEStep 6 — Clean Up the Test Deployment
kubectl delete deployment nginx-test
kubectl delete service nginx-testAllowing External Access Through the Firewall
sudo ufw allow 6443/tcpPort 6443 is the Kubernetes API server; only open it if you genuinely need remote kubectl access from outside the server itself.
Checking k3s Service Status
sudo systemctl status k3sViewing k3s Logs
sudo journalctl -u k3s -fUninstalling k3s (If Needed)
sudo /usr/local/bin/k3s-uninstall.shNext Steps
Once your single-node cluster is running, see Kubernetes Pods, Deployments & Services Explained to understand the core building blocks, and How to Deploy a Stateless Web App to Kubernetes (Step-by-Step) for a real deployment walkthrough.
Common Errors
"kubectl: command not found" — k3s installs kubectl automatically; verify with which kubectl, or use k3s kubectl explicitly if the standalone binary isn't linked.
Node shows "NotReady" — wait 30-60 seconds after install for all system components to initialize; check sudo journalctl -u k3s for specific errors if it persists.
Best Practices
- Use k3s for single-node or small multi-node setups rather than full kubeadm, unless you have a specific reason requiring the complete upstream distribution
- Restrict API server access (port 6443) to trusted IPs if enabling remote access
- Keep k3s updated for security patches
Continue Reading
- What Is Kubernetes and When Do You Need It on a VPS?
- Kubernetes Pods, Deployments & Services Explained
- How to Deploy a Stateless Web App to Kubernetes (Step-by-Step)
Browse more articles in Kubernetes & Container Orchestration.
