Rancher Guide (Elemental)

1 About SLE Micro in Rancher #

This documentation covers a special build of SLE Micro to be used for Kubernetes nodes managed by Rancher.

It's a containerized build with the following properties:

Enabling full-stack management

It enables Rancher to manage the full node stack. From the operating system (OS) to Kubernetes to the workloads running on Kubernetes.

Using only container registry

The Elemental stack provides the means to deploy SLE Micro through a container image.

This removes the need for package based infrastructure (like RMT or SUSE Manager) to install and update the OS on Kubernetes nodes.

Everything is served from (OCI compatible) container registries, the standard infrastructure when Kubernetes is in use.

Seamless integration

The operating system can be treated like a containerized workload. Typical container build workflows, including security scans, can be applied to SLE Micro.

Fully cloud-native

The containerized build of SLE Micro provides image-based, declarative installations and upgrades of Kubernetes (k3s or RKE2) cluster nodes running an immutable operating system.

All operations are cloud-native and can be managed either through the Rancher OS management extension or via normal Kubernetes means like kubectl.

Rancher integration

The "Elemental - OS Management" extension to Rancher Manager provides a UI extension to manage a node's lifecycle through deployment, upgrade, redeployment and decommisioning.

Runs everywhere

SLE Micro with Elemental runs on bare metal, edge, virtualized, or in the cloud and is available for AMD64 (Intel64) and ARM aarch64.

This all comes with a fundamental different approach to day one and day two operations.

There's esp. no transactional-update available since a deployed system is immutable. Cloud-native principles demand a node redeployment if its configuration changes.

This deployment method of SLE Micro is the right choice if you already have all your workloads containerized. It saves you from running an additonal package-based infrastructure. All day 1 and day 2 operations can be handled from within Kubernetes, using only existing OCI image servers.

Rancher OS management is based on the Elemental stack and uses the following services

elemental-operator: Links OS management tasks to Kubernetes
elemental-toolkit: Client-side stack, enabling declarative, cloud-native OS management
elemental OS management extension: Rancher UI plugin for OS management

2 Rancher OS management documentation #

The Elemental Teal documentation comprises the following parts:

3 Legal Notice #

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or (at your option) version 1.3; with the Invariant Section being this copyright notice and license. A copy of the license version 1.2 is included in the section entitled “GNU Free Documentation License”.

For SUSE trademarks, see https://www.suse.com/company/legal/. All other third-party trademarks are the property of their respective owners. Trademark symbols (®, ™ etc.) denote trademarks of SUSE and its affiliates. Asterisks (*) denote third-party trademarks.

All information found in this book has been compiled with utmost attention to detail. However, this does not guarantee complete accuracy. Neither SUSE LLC, its affiliates, the authors, nor the translators shall be held liable for possible errors or the consequences thereof.