P2P multi-node cluster with AuroraBoot

Deploying Kubernetes at the Edge can be a complex and time-consuming process, especially when it comes to setting up and managing multiple clusters. To make this process easier, Kairos leverages peer-to-peer technology to automatically coordinate and create Kubernetes clusters without the need of a control management interface.

To leverage p2p self-coordination capabilities of Kairos, you will need to configure the network_token under the p2p configuration block in your cloud-config file. Once you have set this, Kairos will handle the configuration of each node.

Description

In the following example we are going to bootstrap a new multi-node, single cluster with Kairos. We will use at least 2 nodes, one as a master and one as a worker. Note how we don’t specify any role, or either pin any IP in the following configurations.

We will first create a cloud config file for our deployment, and then run AuroraBoot locally. We then start 2 VMs configured for netbooting.

Prepare your cloud-config file

Consider the following example, which uses cloud-config to automatically configure the cluster:

We start by creating a cloud config file locally, that could look similar to this:

#cloud-config

hostname: kairoslab-{{ trunc 4 .MachineID }}
users:
- name: kairos
  passwd: kairos
  ssh_authorized_keys:
  # Replace with your github user and un-comment the line below:
  - github:mudler
  - github:mauromorales

p2p:
 disable_dht: true # Enable for LAN-only clusters
 network_token: ""

As we want the installation to be triggered automatically, we add also the install block:

install:
 auto: true
 device: "auto"
 reboot: true

In order to leverage p2p and automatic node co-ordination, we need to generate a unique pre-shared token that will be used by all the nodes that we want to be part of our cluster.

We can generate a network token by using the edgevpn images, by running it locally:

$ docker run -ti --rm quay.io/mudler/edgevpn -b -g
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

This command will generate a network token that we can use in the configuration, which now looks like the following:

#cloud-config

# https://github.com/kairos-io/kairos/issues/885
config_url: ""

install:
 auto: true
 device: "auto"
 reboot: true

hostname: kairoslab-{{ trunc 4 .MachineID }}
users:
- name: kairos
  passwd: kairos
  ssh_authorized_keys:
  - github:mudler
  - github:mauromorales

p2p:
 disable_dht: true #Enabled by default
 network_token: "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"

Change also accordingly the users that can access to the machine:

ssh_authorized_keys:
- github:mudler <--- put your GitHub handle here

Provisioning with AuroraBoot

We now can run AuroraBoot with quay.io/kairos/opensuse:leap-15.5-standard-amd64-generic-v3.0.2-k3sv1.29.0-k3s1 to provision openSUSE Leap machines with those k3s and kairos versions.

AuroraBoot takes cloud-config files also from STDIN, so we will pipe the configuration file to it, and specify the container image that we want to use for our nodes:

cat <<EOF | docker run --rm -i --net host quay.io/kairos/auroraboot \
                    --cloud-config - \
                    --set "container_image=quay.io/kairos/opensuse:leap-15.5-standard-amd64-generic-v3.0.2-k3sv1.29.0-k3s1"
#cloud-config

# https://github.com/kairos-io/kairos/issues/885
config_url: ""

install:
 auto: true
 device: "auto"
 reboot: true

hostname: kairoslab-{{ trunc 4 .MachineID }}
users:
- name: kairos
  passwd: kairos
  ssh_authorized_keys:
  - github:mudler
  - github:mauromorales
p2p:
 disable_dht: true #Enabled by default
 network_token: "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"
EOF

Booting and access the cluster

Start the Machines (VM, or baremetal) with Netboot ( see also here ) and wait for the installation to finish.

Afterward, you should be able to ssh to one of the machines and be able to use your Kubernetes cluster:

$ ssh kairos@IP
$ sudo su -
$ kairos get-kubeconfig > kubeconfig
$ KUBECONFIG=kubeconfig k9s

Notes

By default, the Kubernetes API endpoint is not exposed outside the VPN. This is an opinionated configuration from Kairos. To check out configurations without VPN, see also the KubeVIP example.

Troubleshooing

During the first-boot, you can check the provisioning status by looking at the kairos-agent logs:

$ systemctl status kairos-agent
$ journalctl -fu kairos-agent

See also

• Installation with p2p
• P2P Architecture