Configuring Automatic High Availability in Kairos
Note
This feature is crazy and experimental! Do not run in production servers. Feedback and bug reports are welcome, as we are improving the p2p aspects of Kairos.To enable automatic HA rollout, enable the p2p.auto.ha.enable option in your cloud-config, and set up a number of master_nodes. The number of master_nodes is the number of additional masters in addition to the initial HA role. There will always be a minimum of 1 master, which is already taken into account. For example, setting up master_nodes to two will result in a total of 3 master nodes in your cluster.
To make this process even easier, Kairos automatically configures each node in the cluster from a unique cloud-config. This way, you don’t have to manually configure each node, but provide instead a config file for all of the machines during Installation.
Here is an example of what your cloud-config might look like:
#cloud-config
hostname: kairoslab-{{ trunc 4 .MachineID }}
users:
- name: kairos
ssh_authorized_keys:
# Replace with your github user and un-comment the line below:
# - github:mudler
p2p:
# Disabling DHT makes co-ordination to discover nodes only in the local network
disable_dht: true #Enabled by default
# network_token is the shared secret used by the nodes to co-ordinate with p2p.
# Setting a network token implies auto.enable = true.
# To disable, just set auto.enable = false
network_token: ""
# Automatic cluster deployment configuration
auto:
# Enables Automatic node configuration (self-coordination)
# for role assignment
enable: true
# HA enables automatic HA roles assignment.
# A master cluster init is always required,
# Any additional master_node is configured as part of the
# HA control plane.
# If auto is disabled, HA has no effect.
ha:
# Enables HA control-plane
enable: true
# Number of HA additional master nodes.
# A master node is always required for creating the cluster and is implied.
# The setting below adds 2 additional master nodes, for a total of 3.
master_nodes: 2
Note: In order for the automatic HA rollout to work, you need to generate a network token. You can find more information on how to do this in the dedicated section.