Architecture

This section contains refrences to how Kairos works internally.

Setup process

kairos node at first boot will start the kairos-agent service, you can always check what’s happening by running journalctl -fu kairos-agent.

This service will setup k3s and edgevpn dynamically on first-boot, once it configures the machine it does not run on boot anymore, unless /usr/local/.kairos/deployed is removed..

Those are the steps executed in sequence by the kairos-agent service:

• Will create a edgevpn@kairos service and enabled on start. The configuration for the connection is stored in /etc/systemd/system.conf.d/edgevpn-kairos.env and depends on the cloud-init configuration file provided during installation time
• Automatic role negotiation starts, nodes will co-ordinate for an IP and a role
• Once roles are defined a node will either set the k3s or k3s-agent service. Configuration for each service is stored in /etc/sysconfig/k3s and /etc/sysconfig/k3s-agent respectively

Paths

The following paths are relevant for Kairos:

Path	Description
/usr/local/.kairos/deployed	Sentinel file written after bootstrapping is complete. Remove to retrigger automatic bootstrap
/usr/local/.kairos/lease	IP Lease of the node in the network. Delete to change IP address of the node