RISC-V Runner Device Plugin

A Kubernetes device plugin and node labeller for RISC-V worker nodes. It provides two components:

• k8s-device-plugin — Registers a riseproject.com/runner resource (quantity 1) with the kubelet on each node. Pods that request this resource get exclusive scheduling, giving you concurrency control over CI jobs per node.
• k8s-node-labeller — Detects the RISC-V SOC via the device tree (/sys/firmware/devicetree/base/compatible) and labels the node with riseproject.dev/board=<board-name>, enabling node selection by board type.

Architecture

┌──────────────────────┐     ┌──────────────────────┐
│  k8s-device-plugin   │     │  k8s-node-labeller   │
│                      │     │                      │
│  Registers resource  │     │  Reads device tree   │
│  riseproject.com/    │     │  Labels node with    │
│  runner=1 via gRPC   │     │  riseproject.dev/    │
│                      │     │  board=<name>        │
│  Talks to: kubelet   │     │  Talks to: API server│
│  RBAC: none          │     │  RBAC: nodes get/patch│
└──────────────────────┘     └──────────────────────┘
        DaemonSet                   DaemonSet

Both run as DaemonSets on riscv64 nodes. They share the pkg/soc package for SOC detection but are built and deployed as separate container images.

Project Structure

├── cmd/
│   ├── k8s-device-plugin/main.go       # Device plugin binary
│   └── k8s-node-labeller/main.go       # Node labeller binary
├── pkg/
│   ├── plugin/plugin.go                # Device plugin gRPC server
│   ├── soc/detect.go                   # SOC detection from device tree
│   └── labeler/labeler.go              # Node labeling via k8s API
├── Dockerfile                          # Image for k8s-device-plugin
├── labeller.Dockerfile                 # Image for k8s-node-labeller
├── Makefile
├── k8s-ds-device-plugin.yaml           # DaemonSet manifest
└── k8s-ds-node-labeller.yaml           # DaemonSet + RBAC manifest

Board Mapping

The node labeller reads /sys/firmware/devicetree/base/compatible and matches entries against a built-in map:

Compatible String	Board Label
scaleway,em-rv1-c4m16s128-a	scw-em-rv1
sophgo,mango	cloudv10x-pioneer

If no match is found, the first compatible entry is sanitized and used as the label value. To add new boards, update the boardMap in pkg/soc/detect.go.

Prerequisites

• Go 1.22+
• Podman (for cross-compilation to riscv64)
• A Kubernetes cluster with riscv64 worker nodes

Build

# Build both binaries for linux/riscv64
make build

# Build only one
make build-device-plugin
make build-node-labeller

Container Images

# Build both images
make container-build

# Build and push both images
make container-push

# Build individually
make container-build-device-plugin
make container-build-node-labeller

Images are pushed to a single repository with two tags:

• rg.fr-par.scw.cloud/funcscwriseriscvrunnerappqdvknz9s/riscv-runner:device-plugin-latest
• rg.fr-par.scw.cloud/funcscwriseriscvrunnerappqdvknz9s/riscv-runner:node-labeller-latest

Override the repository:

make container-push IMAGE_REPO=myregistry.io/my-namespace/riscv-runner

Deploy

kubectl apply -f k8s-ds-device-plugin.yaml
kubectl apply -f k8s-ds-node-labeller.yaml

Verify

After deployment, check that the device plugin registered the resource:

kubectl describe node <node-name> | grep riseproject

Output should contain:

  riseproject.com/runner:  <...>
  riseproject.dev/board=<...>

Usage

Request the runner resource in your pod spec to limit concurrency to one job per node:

resources:
  limits:
    riseproject.com/runner: "1"

Use the board label for node selection:

nodeSelector:
  riseproject.dev/board: scw-em-rv1