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Manual Multi-Node High Availability Cluster
K3s
Please refer to the k3s HA documentation.K0s
Please refer to the k0s multi-node manual install documentation.Production Considerations
This example is for learning purposes. In production environments, it’s recommended to use a load balancer in front of the highly available control plane nodes rather than exposing all control plane nodes directly. For a production-ready setup with a load balancer, see our Self-coordinating P2P Multi-Node Cluster with High Availability and KubeVIP example.This document describes how to configure Kairos with either k3s or k0s by following the same documentation outline. It is implied that you are using a Kairos version with either k3s or k0s included in the standard images.
New cluster
To run Kairos in this mode, you must have an odd number of server nodes.
The first control plane node that we will launch is considered the cluster initializer.
#cloud-config
hostname: metal-{{ trunc 4 .MachineID }}
users:
- name: kairos
# Change to your pass here
passwd: kairos
groups:
- admin
#ssh_authorized_keys:
## Add your github user here!
#- github:mudler
k3s:
enabled: true
args:
- --cluster-init
# Token will be generated if not specified at /var/lib/rancher/k3s/server/node-token
env:
K3S_TOKEN: "TOKEN_GOES_HERE"
#cloud-config
hostname: metal-{{ trunc 4 .MachineID }}
users:
- name: kairos # Change to your own user
passwd: kairos # Change to your own password
groups:
- admin # This user needs to be part of the admin group
ssh_authorized_keys:
- github:<YOUR_GITHUB_USER> # replace with your github user
k0s:
enabled: true
After launching the first control plane, join the others
#cloud-config
hostname: metal-{{ trunc 4 .MachineID }}
users:
- name: kairos
# Change to your pass here
passwd: kairos
groups:
- admin
ssh_authorized_keys:
# Add your github user here!
- github:mudler
k3s:
enabled: true
args:
- --server https://<ip or hostname of server1>:6443
env:
K3S_TOKEN: "TOKEN_GOES_HERE"
#cloud-config
hostname: metal-{{ trunc 4 .MachineID }}
users:
- name: kairos # Change to your own user
passwd: kairos # Change to your own password
groups:
- admin # This user needs to be part of the admin group
ssh_authorized_keys:
- github:<YOUR_GITHUB_USER> # replace with your github user
k0s-worker:
enabled: true
args:
- --token-file /etc/k0s/token
write_files:
- path: /etc/k0s/token
permissions: 0644
content: |
<TOKEN> # generate it on your cluster init node by running `k0s token create --role=controller`
Now you have a highly available control plane.
Joining a worker
Joining additional worker nodes to the cluster follows the same procedure as a single-node cluster.
#cloud-config
hostname: metal-{{ trunc 4 .MachineID }}
users:
- name: kairos
# Change to your pass here
passwd: kairos
groups:
- admin
#ssh_authorized_keys:
## Add your github user here!
#- github:mudler
k3s-agent:
enabled: true
env:
K3S_TOKEN: "TOKEN_GOES_HERE"
K3S_URL: "https://<ip or hostname of server1>:6443"
#cloud-config
hostname: metal-{{ trunc 4 .MachineID }}
users:
- name: kairos # Change to your own user
passwd: kairos # Change to your own password
groups:
- admin # This user needs to be part of the admin group
ssh_authorized_keys:
- github:<YOUR_GITHUB_USER> # replace with your github user
k0s-worker:
enabled: true
args:
- --token-file /etc/k0s/token
write_files:
- path: /etc/k0s/token
permissions: 0644
content: |
<TOKEN> # generate it on your master node by running `k0s token create --role=worker`
External DB
K0s
This section hasn’t been reworked to be used with the k0s distribution yet.K3s requires two or more server nodes for this HA configuration. See the K3s requirements guide for minimum machine requirements.
When running the k3s as a server, you must set the datastore-endpoint parameter so that K3s knows how to connect to the external datastore.
#cloud-config
hostname: metal-{{ trunc 4 .MachineID }}
users:
- name: kairos
# Change to your pass here
passwd: kairos
groups:
- admin
#ssh_authorized_keys:
## Add your github user here!
#- github:mudler
k3s:
enabled: true
args:
- --datastore-endpoint mysql://username:password@tcp(hostname:3306)/database-name
# Token will be generated if not specified at /var/lib/rancher/k3s/server/node-token
env:
K3S_TOKEN: "TOKEN_GOES_HERE"