Flatcar

This flavor supports provisioning k8s clusters outside of VPC using Flatcar as a base OS. It uses kubeadm for setting up control plane and uses cilium with VXLAN for pod networking.

Specification

Notes

This flavor is identical to the default flavor with the exception that it provisions k8s clusters without VPC using Flatcar as a base OS. Since it runs outside of VPC, native routing is not supported in this flavor and it uses VXLAN for pod to pod communication.

Usage

Initialization

Before generating the cluster configuration, it is required to initialize the management cluster with Ignition support to provision Flatcar nodes:

export EXP_KUBEADM_BOOTSTRAP_FORMAT_IGNITION=true
clusterctl init --infrastructure linode-linode --addon helm

Import the Flatcar image

Flatcar is not officially provided by Akamai/Linode so it is required to import a Flatcar image. Akamai support is available on Flatcar since the release 4012.0.0: all releases equal or greater than this major release will fit.

To import the image, it is recommended to follow this documentation: https://www.flatcar.org/docs/latest/installing/community-platforms/akamai/#importing-an-image

By following this import step, you will get the Flatcar image ID stored into IMAGE_ID.

Configure and deploy the workload cluster

1. Set the Flatcar image name from the previous step:

   export FLATCAR_IMAGE_NAME="${IMAGE_ID}"
   

2. Generate cluster yaml

   clusterctl generate cluster test-cluster \
       --kubernetes-version v1.29.1 \
       --infrastructure linode-linode \
       --flavor kubeadm-flatcar > test-cluster.yaml
   

3. Apply cluster yaml

   kubectl apply -f test-cluster.yaml