Multi Node k3s cluster

In the example below we will use a bare metal host to provision a Kairos cluster in the local network with K3s and one master node.

Installation

Use the standard images which contain k3s.

Follow the Installation documentation, using the following cloud config for the master and worker respectively:

• server
• worker

#cloud-config

hostname: metal-{{ trunc 4 .MachineID }}
users:
- name: kairos
  # Change to your pass here
  passwd: kairos
  ssh_authorized_keys:
  # Replace with your github user and un-comment the line below:
  # - github:mudler

k3s:
  enabled: true
  args:
  - --disable=traefik,servicelb

#cloud-config

hostname: metal-{{ trunc 4 .MachineID }}
users:
- name: kairos
  # Change to your pass here
  passwd: kairos
  ssh_authorized_keys:
  # Add your github user here!
  - github:mudler

k3s-agent:
  enabled: true
  args:
  - --with-node-id
  env:
   K3S_TOKEN: <MASTER_SERVER_TOKEN>
   K3S_URL: https://<MASTER_SERVER_IP>:6443

After having deployed the master node, you can extract the values for the following variables:

• K3S_TOKEN from /var/lib/rancher/k3s/server/node-token
• K3S_URL same IP that you use to log into your master node

Since this is a fully manual installation, you are in charge of setting all arguments that your setup will require, by use of the args attribute for both the master and server nodes. In this particular case:

• --disable=traefik,servicelb will, as you proably guessed it, disable traefik and servicelb (the default k3s load balancer).
• --with-node-id will configure the agent to use the node ID to communicate with the master node

To find out more about args configuration from k3s, follow their server and agent documentation.