Host service (runs as llmuser, owns /opt/fluxgym + GPU access) that runs
sd-scripts SDXL LoRA training on demand for arbo — the infra-ops half of the
in-arbo LoRA training Phase 1 ownership split (vh/arbo
docs/contracts/in-arbo-lora-training-phase1.contract.md §4.1/§2).
- Fixed-invocation only (INV-T7): bounded params -> one sd-scripts command
shape; every param range/allowlist/path-containment checked before spawn;
bad request = 422, never a silent downgrade. 14 unit tests green.
- Thin supervisor: never imports torch; subprocesses the fluxgym venv's
accelerate. 1-job-at-a-time (arbo lease is the serializer, 409 is backstop).
Durable job records + boot reconciliation (§4.3).
- API: POST /train, GET /train/{id}[/log], POST /train/{id}/cancel,
GET /gpu-status (per-device VRAM + tts_on_3090 co-OOM signal), GET /healthz.
- Wire-shape (§7 resolved with comfy-dev): shared /worktank/arbo/train handoff
(group arbotrain, setgid 2770); worker binds 0.0.0.0:8203, arbo reaches via
host.docker.internal:host-gateway (reachability proven on 172.20.0.1:8203);
device-aware TTS steering via /gpu-status.
Deployed to irv-ml1 via playbooks/deploy-lora-training-worker.yaml (elway,
idempotent); systemd unit active; /healthz + /gpu-status verified live.
