feat(examples): add gpu-k8s-arc-sglang GPU Kubernetes deployment example

[powderluv]

Summary

Adds a self-contained example under examples/gpu-k8s-arc-sglang/ for standing up a native k0s GPU Kubernetes cluster on SPUR nodes: ARC (actions-runner-controller) CI runners for a sglang fork, gated auto-deploy of an sglang serving Deployment, and optional backend RoCE/RDMA for distributed inference.

Genericized from a working AMD MI355X (gfx950) 4-node deployment.

What's included

• Cluster (10-cluster/) — k0s + Calico bird native routing over a WireGuard mesh (single overlay).
• GPU (20-gpu/) — AMD GPU device plugin + node labelling.
• ARC (30-arc/) — GPU runner scale set (hand-authored dind spec so /dev/kfd+/dev/dri reach the dind sidecar) and a non-GPU deploy runner with least-privilege RBAC; GitHub App setup docs.
• Serving (40-serving/) — sglang Deployment/Service/PVC/Ingress (ROCm, ungated model) + a gated fork-CI deploy job that kubectl applys on green CI via an in-cluster ServiceAccount (scoped to the sglang namespace).
• RDMA/DI (50-rdma/) — RoCEv2 pod exposure (hostNetwork + SR-IOV options), 2-node tensor-parallel, and prefill/decode disaggregation (MoRI) reference manifests.
• Top-level bootstrap.sh / teardown.sh / Makefile / README.md / RUNBOOK.md template.

Genericization / safety

Redacted for public publication: hostnames → gpu-node-N / head-node, provider mount path → /mnt/scratch, the internal operational RUNBOOK replaced with a fill-in template. Mesh/rail/pod subnets (10.44.0.0/16, etc.) are RFC1918 example config the example itself provisions. No secrets/tokens/keys — github-app-secret.example.yaml is a placeholder template.

Status

Opened as a draft / review branch. Cluster bring-up, the GPU device plugin, ARC runners, and the gated serving deploy path were validated on real MI355X hardware. The 50-rdma/ distributed-inference manifests are references — cross-node RDMA KV-transfer has an open NIC-QoS (nicctl PFC/DCQCN) dependency noted inline.

🤖 Generated with Claude Code

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.

Additional details and impacted files

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- Hits        29656    29652       -4     
- Misses      12193    12197       +4     

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