Single Node k3s cluster

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

Installation

Use the standard images which contain k3s.

Follow the Installation documentation, and use the following cloud config file with Kairos:

#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:
  - --node-label "nodetype=small"

write_files:
- path: /var/lib/rancher/k3s/server/manifests/myapp.yaml
  permissions: "0644"
  content: |
    apiVersion: v1
    kind: Namespace
    metadata:
      name: myapp
    ---
    apiVersion: v1
    kind: ConfigMap
    metadata:
      name: foobar
      namespace: myapp
    data:
      foo: bar    

Notably:

• We use the k3s block to set the node label
• In a single-node setup, you may wish to use a non-generated node name. This can be achieved with these options:

  k3s:
    enabled: true
    replace_args: true
    args:
    - --node-name=my-node
  

  Note

  replace_args replaces all arguments otherwise passed to k3s by Kairos with those supplied here. Make sure you pass all the arguments you need.
• We use write_files to write manifests to the default k3s manifest directory (/var/lib/rancher/k3s/server/manifests/) see docs to create a Namespace and ConfigMap.