Architecture

Kubermatic KubeOne automates cluster operations on all your cloud, on-prem, edge, and IoT environments. It comes as a CLI that allows you to manage the full lifecycle of your clusters, including installing and provisioning, upgrading, repairing, and unprovisioning them.

KubeOne utilizes Kubernetes’ kubeadm for handling provisioning and upgrading tasks. Kubeadm allows us to follow the best practices and create conformant and production-ready clusters.

Most of the tasks are carried out by running commands over SSH, therefore the SSH access to the control plane nodes is required. Such tasks include installing and upgrading dependencies (such as container runtime and Kubernetes binaries), generating and distributing configuration files and certificates, running kubeadm, and more. The cluster components and addons are applied applied programmatically using client-go and controller-runtime libraries. By default, KubeOne deploys the Canal CNI plugin, metrics-server, NodeLocalDNS, and Kubermatic machine-controller.

For officially supported providers, the worker nodes are managed by using the Kubermatic machine-controller based on the Cluster-API. For other providers, the worker nodes can be managed by using KubeOne Static Workers feature.

This approach allows us to manage clusters on any infrastructure, is it cloud, on-prem, baremetal, Edge, or IoT.

The following diagram shows the KubeOne’s architecture, including what tasks should be done by the user, what tasks are done by KubeOne, and in which particular order. Additional details about concepts used by KubeOne can be found in the Concepts document.

KubeOne Architecture Diagram

1 This diagram shows officially supported providers. KubeOne is not limited to those providers and is supposed to work on any infrastructure out of the box, for example, on bare-metal. Officially supported providers have additional features, such as Terraform integration, example Terraform configurations that can be used to create the initial infrastructure, and the machine-controller support.

2 Kubermatic Machine Controller is available only for officially supported providers. For non-officially supported providers, you can provision machines manually using KubeOne’s Static Workers feature.