RackN has launched an open source “Edge Lab” reference architecture for building automated, multi-node Raspberry Pi clusters using its Digital Rebar platform for evaluating edge computing systems or emulating cloud platforms.

RackN has posted open source code, instructions, and hardware recommendations on GitHub for setting up a Raspberry Pi cluster that works with its RackN Digital Rebar Platform (DRP). Users can launch an automated Digital Rebar Provisioning cluster with 4x or 8x network-switched Raspberry Pi 4 SBCs and cluster kits for as little as $500.

Edge Lab software implemented using an up to 8x Pi Cloudlet cluster case (left) and conceptual diagram
(click images to enlarge)

Edge Lab is designed as an entry level platform for evaluating or prototyping edge-compute applications or emulating hardware usage on cloud-based systems. The desktop PC based platform can also be used for cloud technology training, including learning about software like Kubernetes.

Edge Lab can help “duplicate the data center API ops experience” to expose how edge computers or cloud servers interact with cloud software “without the cost, noise and time required to DIY,” writes Rob Hirschfeld, CEO of RackN in a recent blog announcement. The software and reference design enables developers of cloud platforms and cloud-native edge computer deployments to better understand hardware processes that are increasingly being abstracted by multiple layers of software.

Edge Lab is based on Rackn’s Digital Rebar — a “self-managed hardware-neutral data center automation platform for provisioning and managing infrastructure as code (IaC),” says RackN. The Digital Rebar core is proprietary, but the platform provides both an open API for operating a data center and an open ecosystem catalog that offers bare metal provisioning workflow for automating processes. These include firmware patching, out-of-band management, OS installation, and deploying platforms like Kubernetes and vCenter. The software is built from a single Golang executable.

The Edge Lab software includes an open source version of the Linux-ready, cross-platform Digital Rebar. The software runs on the Raspberry Pi’s as well as a WiFi-connected desktop PC. The cluster operates as an isolated physical network and does not include a cloud component.

Edge Lab provides zero-touch remote operation and basic infrastructure as code (IaC) capabilities required for real environments, says Rackn. Features include PXE boot, immutable O/S, and API-driven automation control of Raspberry Pi’s to build Kubernetes (k3s) and OpenFaaS stacks. The default implementation is a cluster that implements the lightweight k3s version of Kubernetes.

The system downloads IaC modules from the RackN catalog and does not require firewall rules or VPNs. Users can tap into Digital Rebar infrastructure APIs to automate platforms with Terraform, Ansible or other tools. Because the Pi lacks out-of-band management, resets are enabled via the Digital Rebar Runner soft reboot or a manual power reset.

Edge Lab setup ith Yahboom cluster case

Hardware components that are required to build an Edge lab “desktop datacenter” include 4x Raspberry Pi 4 Model B SBCs with 4GB RAM, each loaded with a 32GB microSD card. Other reference components include multiple Ethernet cables and a micro-HDMI to HDMI cable. You will need to add your own local HDMI-enabled monitor, a USB keyboard, and a router.

Optional, recommended features include Power-over-Ethernet (PoE) HATs for each Pi and a 5-port PoE Gigabit Ethernet switch. The project also recommends a Yahboom or fan-cooled iUniker RPi cluster case. Optionally, you can move to an 8-node Cloudlet case, in which case you will need a USB power hub.

The Edge Lab software is ready to deploy now but will continue to improve. The project is looking for participants from the larger Digital Rebar operator community and beyond to help support additional edge scenarios and hardware beyond the Raspberry Pi.

 
Further information

The Edge Lab software is available for free download on the EdgeLab.digital GitHub page, which also includes links to recommended hardware components and setup instructions. More information on Digital Rebar may be found on the RackN website.