Installation

SUSE® Rancher Prime OS Manager stack provides OS management using OCI containers and Kubernetes. The SUSE® Rancher Prime OS Manager stack installation encompasses the installation of the SUSE® Rancher Prime OS Manager Operator into the management cluster and the creation and use of installation media to provide the OS into the Cluster Nodes. See Architecture section to read about the interaction of the components.

The installation configuration is mostly applied and set as part of the registration process. The registration process is done by the elemental-register (the SUSE® Rancher Prime OS Manager Operator client part) who is the responsible to register nodes in a Rancher management cluster and fetch the installation configuration.

Please refer to the Quick Start guide for simple step by step deployment instructions.

The SUSE® Rancher Prime OS Manager Operator is responsible for managing the SUSE® Rancher Prime OS Manager versions and maintaining a machine inventory to assist with edge or bare metal installations. SUSE® Rancher Prime OS Manager Operator requires a cluster including the Rancher Manager and it can be installed with a helm chart.

See SUSE® Rancher Prime OS Manager Operator helm chart reference for install, uninstall, upgrade and configuration details.

Once the SUSE® Rancher Prime OS Manager Operator is up and running within the management cluster a couple of kubernetes resources are required in order to prepare an SUSE® Rancher Prime OS Manager based cluster deployment.

A Rancher Cluster resource is also required to deploy SUSE® Rancher Prime OS Manager, it can be manually created as exemplified in the Quick Start guide or created from the Rancher 2.6 UI.

The installation media is the media that will be used to kick start an OS deployment. Currently the supported media is a live ISO. The live ISO must include the registration configuration yaml hence it must crafted once the MachineRegistration is created. The installation media is generated by creating Seed Image resources (see quick start and custom images).

The live ISO supports PXE booting for direct integration with SUSE Manager.

Within MachineRegistration only a subset of OS installation parameters can be configured, all available parameters are listed at MachineRegistration reference page.

In order to configure the installation beyond the common options provided within the elemental.install section a config.yaml configuration file can be included into the ISO (see Custom Images). Note any configuration applied as part of elemental.install section of the MachineRegistration will be applied on top of the settings included in any custom config.yaml file.

Most likely the cloud-init configuration is enough to configure and set the deployed node at boot, however if for some reason firstboot actions or scripts are required it is possible to also include Rancher System Agent plans into the installation media. Refer to the Plans section for details and some example plans. The plans could be included into the squashed rootfs at /var/lib/elemental/agent/plans folder and they would be seen by the system agent at firstboot.

The installation starts by booting the installation media on a node. Once the installation media has booted it will attempt to contact the management cluster and register to it by calling elemental-register command. As the registration yaml configuration is already included into the ISO elemental-register knows the registration URL and any other required data for the registration.

On a succeeded registration the installation media will start the installation into the host based on the configuration already included in the media and the MachineRegistration parameters. As soon as the installation is done the node is ready to reboot. The deployed OS includes a system agent plan to kick start a regular rancher provisioning process to install the selected kubernetes version, once booted, after some minutes the node installation is finalized and the node is included into the cluster and visible through the Rancher UI.

Once the operating system is installed the OS partition table, according to default values, will look like

Note this is the basic structure of any OS built by the SUSE® Rancher Prime OS Manager Toolkit.

One of the characteristics of SUSE® Rancher Prime OS Manager OSes is the setup of an immutable root filesystem where some ephemeral or persistent locations are applied on top of it. The default folders structure is listed in the matrix below.