Playbook: 3-Node K3s High Availability Cluster Setup

This playbook describes how to deploy a production-ready, highly available K3s cluster with three control-plane nodes.

Overview

A 3-node HA setup uses an embedded etcd database for the control plane, providing resilience against the failure of any single node.

Prerequisites

• 3 Linux nodes (e.g., Ubuntu 24.04 or Talos OS).
• Static IP addresses for all nodes.
• SSH access between nodes (or console access).

Step 1: Initialize the First Node

On the first node (node-01), run:

curl -sfL https://get.k3s.io | sh -s - server \
  --cluster-init \
  --tls-san <cluster-vip-or-fqdn>

Step 2: Join the Second and Third Nodes

Retrieve the node token from node-01:

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

On node-02 and node-03, run:

curl -sfL https://get.k3s.io | sh -s - server \
  --server https://<node-01-ip>:6443 \
  --token <node-token>

Step 3: Verify the Cluster

Check the status of the nodes:

kubectl get nodes

Ensure all 3 nodes show Ready and have the control-plane,master roles.

Step 4: Configuration Details

• Storage: By default, K3s uses local storage. For HA, it is recommended to use Longhorn or NFS CSI.
• Networking: MetalLB should be configured for LoadBalancer services.

Sources / References

• K3s High Availability with Embedded etcd
• K3s Installation Options

Contribution Metadata

• Last reviewed: 2026-04-24
• Confidence: high