SUSE Edge 3.1.0 Documentation #

SUSE Edge is comprised of both existing SUSE and Rancher components along with additional features and components built by the Edge team to enable us to address the constraints and intricacies required in edge computing. The components used within both the management and downstream clusters are explained below, with a simplified high-level architecture diagram, noting that this isn’t an exhaustive list:

3.1.1 Management Cluster #

 

• Management: This is the centralized part of SUSE Edge that is used to manage the provisioning and lifecycle of connected downstream clusters. The management cluster typically includes the following components:

  • Multi-cluster management with Rancher Prime (Chapter 4, Rancher), enabling a common dashboard for downstream cluster onboarding and ongoing lifecycle management of infrastructure and applications, also providing comprehensive tenant isolation and IDP (Identity Provider) integrations, a large marketplace of third-party integrations and extensions, and a vendor-neutral API.

  • Linux systems management with SUSE Manager, enabling automated Linux patch and configuration management of the underlying Linux operating system (*SLE Micro (Chapter 7, SLE Micro)) that runs on the downstream clusters. Note that while this component is containerized, it currently needs to run on a separate system to the rest of the management components, hence labelled as "Linux Management" in the diagram above.

  • A dedicated Lifecycle Management (Chapter 20, Upgrade Controller) controller that handles management cluster component upgrades to a given SUSE Edge release.

  • Remote system on-boarding into Rancher Prime with Elemental (Chapter 11, Elemental), enabling late binding of connected edge nodes to desired Kubernetes clusters and application deployment, e.g. via GitOps.

  • An Optional full bare-metal lifecycle and management support with Metal3 (Chapter 8, Metal³), MetalLB (Chapter 17, MetalLB), and CAPI (Cluster API) infrastructure providers, enabling the full end-to-end provisioning of baremetal systems that have remote management capabilities.

  • An optional GitOps engine called Fleet (Chapter 6, Fleet) for managing the provisioning and lifecycle of downstream clusters and applications that reside on them.

  • Underpinning the management cluster itself is SLE Micro (Chapter 7, SLE Micro) as the base operating system and RKE2 (Chapter 14, RKE2) as the Kubernetes distribution supporting the management cluster applications.

3.1.2 Downstream Clusters #

 

• Downstream: This is the distributed part of SUSE Edge that is used to run the user workloads at the Edge, i.e. the software that is running at the edge location itself, and is typically comprised of the following components:

  • A choice of Kubernetes distributions, with secure and lightweight distributions like K3s (Chapter 13, K3s) and RKE2 (Chapter 14, RKE2) (RKE2 is hardened, certified and optimized for usage in government and regulated industries).

  • NeuVector (Chapter 16, NeuVector) to enable security features like image vulnerability scanning, deep packet inspection, and real-time threat and vulnerability protection.

  • Software block storage with Longhorn (Chapter 15, Longhorn) to enable lightweight persistent, resilient, and scalable block-storage.

  • A lightweight, container-optimized, hardened Linux operating system with SLE Micro (Chapter 7, SLE Micro), providing an immutable and highly resilient OS for running containers and virtual machines at the edge. SLE Micro is available for both aarch64 and x86_64 architectures, and it also supports Real-Time Kernel for latency sentitive applications (e.g. telco use-cases).

  • For connected clusters (i.e. those that do have connectivity to the management cluster) two agents are deployed, namely Rancher System Agent for managing the connectivity to Rancher Prime, and venv-salt-minion for taking instructions from SUSE Manager for applying Linux software updates. These agents are not required for management of disconnected clusters.

The above image provides a high-level architectural overview for connected downstream clusters and their attachment to the management cluster. The management cluster can be deployed on a wide variety of underlying infrastructure platforms, in both on-premises and cloud capacities, depending on networking availability between the downstream clusters and the target management cluster. The only requirement for this to function are API and callback URL’s to be accessible over the network that connects downstream cluster nodes to the management infrastructure.

It’s important to recognize that there are distinct mechanisms in which this connectivity is established relative to the mechanism of downstream cluster deployment. The details of this are explained in much more depth in the next section, but to set a baseline understanding, there are three primary mechanisms for connected downstream clusters to be established as a "managed" cluster:

Note

It’s recommended that multiple management clusters are implemented to accommodate the scale of large deployments, optimize for bandwidth and latency concerns in geographically dispersed environments, and to minimize the disruption in the event of an outage or management cluster upgrade. You can find the current management cluster scalability limits and system requirements here.

Directed network provisioning is where you know the details of the hardware you wish to deploy to and have direct access to the out-of-band management interface to orchestrate and automate the entire provisioning process. In this scenario, our customers expect a solution to be able to provision edge sites fully automated from a centralized location, going much further than the creation of a boot image by minimizing the manual operations at the edge location; simply rack, power, and attach the required networks to the physical hardware, and the automation process powers up the machine via the out-of-band management (e.g. via the Redfish API) and handles the provisioning, onboarding, and deployment of infrastructure without user intervention. The key for this to work is that the systems are known to the administrators; they know which hardware is in which location, and that deployment is expected to be handled centrally.

This solution is the most robust since you are directly interacting with the hardware’s management interface, are dealing with known hardware, and have fewer constraints on network availability. Functionality wise, this solution extensively uses Cluster API and Metal³ for automated provisioning from bare-metal, through operating system, Kubernetes, and layered applications, and provides the ability to link into the rest of the common lifecycle management capabilities of SUSE Edge post-deployment. The quickstart for this solution can be found in Chapter 1, BMC automated deployments with Metal³.

Sometimes you are operating in an environment where the central management cluster cannot manage the hardware directly (for example, your remote network is behind a firewall or there is no out-of-band management interface; common in "PC" type hardware often found at the edge). In this scenario, we provide tooling to remotely provision clusters and their workloads with no need to know where hardware is being shipped when it is bootstrapped. This is what most people think of when they think about edge computing; it’s the thousands or tens of thousands of somewhat unknown systems booting up at edge locations and securely phoning home, validating who they are, and receiving their instructions on what they’re supposed to do. Our requirements here expect provisioning and lifecycle management with very little user-intervention other than either pre-imaging the machine at the factory, or simply attaching a boot image, e.g. via USB, and switching the system on. The primary challenges in this space are addressing scale, consistency, security, and lifecycle of these devices in the wild.

This solution provides a great deal of flexibility and consistency in the way that systems are provisioned and on-boarded, regardless of their location, system type or specification, or when they’re powered on for the first time. SUSE Edge enables full flexibility and customization of the system via Edge Image Builder, and leverages the registration capabilities Rancher’s Elemental offering for node on-boarding and Kubernetes provisioning, along with SUSE Manager for operating system patching. The quick start for this solution can be found in Chapter 2, Remote host onboarding with Elemental.

For customers that need to operate in standalone, air-gapped, or network limited environments, SUSE Edge provides a solution that enables customers to generate fully customized installation media that contains all of the required deployment artifacts to enable both single-node and multi-node highly-available Kubernetes clusters at the edge, including any workloads or additional layered components required, all without any network connectivity to the outside world, and without the intervention of a centralized management platform. The user-experience follows closely to the "phone home" solution in that installation media is provided to the target systems, but the solution will "bootstrap in-place". In this scenario, it’s possible to attach the resulting clusters into Rancher for ongoing management (i.e. going from a "disconnected" to "connected" mode of operation without major reconfiguration or redeployment), or can continue to operate in isolation. Note that in both cases the same consistent mechanism for automating lifecycle operations can be applied.

Furthermore, this solution can be used to quickly create management clusters that may host the centralized infrastructure that supports both the "directed network provisioning" and "phone home network provisioning" models as it can be the quickest and most simple way to provision all types of Edge infrastructure. This solution heavily utilizes the capabilities of SUSE Edge Image Builder to create fully customized and unattended installation media; the quickstart can be found in Chapter 3, Standalone clusters with Edge Image Builder.