K3S image for hcloud

This project provides a K3S image that has the core infrastructure components pre-cached for fast K3S HA cluster deployment with Cilium CNI. This significantly reduces the time to join nodes to a K3s cluster.

Features

• Based on Ubuntu 24.04 LTS
• Pre-installed K3s binary and airgap images
• Pre-pulled Cilium CNI images (including Hubble and UI)
• Optimized for both AMD64 and ARM64 architectures
• Configured for Cilium CNI (Flannel disabled)
• Ready-to-use systemd service with HA support
• Environment variable based configuration for TLS SAN and clustering
• Supports embedded etcd for HA control plane

Prerequisites

• Packer >= 1.8.0
• Hetzner Cloud account and API token
• (Optional) Terraform >= 1.0 for automated deployment

Quick Links

• Terraform Example - Production-ready HA cluster deployment
• Environment Config Template - Cluster init config

Building the Images

1. Set up your Hetzner Cloud API token

export HCLOUD_TOKEN="your-hetzner-cloud-api-token"

2. Initialize Packer

packer init k3s-hcloud.pkr.hcl

3. Validate the configuration

packer validate k3s-hcloud.pkr.hcl

4. Build the images

Build both AMD64 and ARM64 images:

packer build k3s-hcloud.pkr.hcl

Build only AMD64:

packer build -only='k3s-hcloud-images.hcloud.k3s-amd64' k3s-hcloud.pkr.hcl

Build only ARM64:

packer build -only='k3s-hcloud-images.hcloud.k3s-arm64' k3s-hcloud.pkr.hcl