Architecture Components
The components required to provide the SUSE® Rancher Prime OS Manager services are:
-
the
elementalcommand line tool -
the
elemental-operatordaemon -
the
elemental-registercommand line tool -
the
elemental-system-agentdaemon -
one or more SUSE® Rancher Prime OS Manager OS container images
elemental command line tool
The elemental tool is part of the SUSE® Rancher Prime OS Manager Toolkit project.
It performs the actual OS installation and upgrade operations on the host and is used to execute the cloud-config directives added in the SUSE® Rancher Prime OS Manager CRDs.
The elemental binary is included in all the base OS images distributed with SUSE® Rancher Prime OS Manager.
elemental-operator daemon
The elemental-operator daemon performs two main tasks:
-
embeds the SUSE® Rancher Prime OS Manager Kubernetes controllers to manage all the SUSE® Rancher Prime OS Manager CRDs
-
exposes the registration endpoints to allow the host to register and download the OS installation configuration during the machine onboarding
The elemental-operator daemon is deployed on the Rancher cluster as a Deployment via the SUSE® Rancher Prime OS Manager Operator Helm Chart.
elemental-register command line tool
The elemental-register binary is the client used to register the host against the registration endpoints exposed by the elemental-operator. It collects and forwards the host data to allow the elemental-operator to fill the SMBIOS and the Hardware label templates.
If the registraton phase is performed successfully, the elemental-register gets the full configuration stored in the MachineRegistration from the elemental-operator. As the last step, the elemental-register client calls the elemental binary passing the retrieved configuration to kick off the OS installation.
elemental-system-agent daemon
The elemental-system-agent is built from the Rancher System Agent project and allows SUSE® Rancher Prime OS Manager to deploy plans to assist with the host provisioning.
Notably, the rancher-system-agent installation and configuration required for the Kubernetes Cluster provisioning service is performed through an elemental-system-agent plan.
SUSE® Rancher Prime OS Manager OS container image
An SUSE® Rancher Prime OS Manager Toolkit OS image is an OCI container image containing all the files that will make up the OS of the target host. It contains not only all the binaries and libraries, but also the kernel and the boot files required by a linux system.
The SUSE® Rancher Prime OS Manager OS image is an opinionated SUSE® Rancher Prime OS Manager Toolkit OS image which is based on SLE Micro and contains specific SUSE® Rancher Prime OS Manager configurations and binaries (the elemental and the elemental-register ones).
The SUSE® Rancher Prime OS Manager OS images are tracked in the ManagedOSVersions resources. The ManagedOSVersions resources are dynamically created from ManagedOSVersionChannel resources. A defaultManagedOSVersionChannel resource is deployed with each SUSE® Rancher Prime OS Manager Operator installation.