comfy-dev's explicit-over-implicit call: arbo now sends train_id, so the
worker no longer derives the loras/trained/{train_id}/ namespace from
output_dir.parent (which coupled it to arbo's handoff layout). train_id is
optional + path-safe-validated; when present it wins, else the path
derivation remains as the fallback. Wired through TrainRequest ->
validate_request -> published_relative_path -> _publish_lora. 18 tests green.
On a train reaching succeeded, IN ADDITION to output/{name}.safetensors
(unchanged download source), COPY it into ComfyUI's loras search path at
/storetank/arbo/models/loras/trained/{train_id}/{name}.safetensors and
return published_lora_name (the ComfyUI-relative LoraLoader string) in the
terminal GET /train/{id} payload (arbo Phase 2 auto-registration, §4.1/§7).
- Copy not move; a publish failure NEVER fails the train (keeps succeeded,
omits published_lora_name, logs the reason to the tailable run log).
- INV-T7-safe: a copy to a fixed computed path, no new free-form args.
- train_id derived from the handoff layout (output_dir.parent.name).
- Provisions loras/trained/ (arbotrain 2775, group-write per the Phase-1
lesson; world-readable/traversable for ComfyUI) via the deploy playbook.
- ComfyUI verified to resolve nested loras subfolders (no flat fallback).
- Pure path helper unit-tested; 16 tests green.
The first real arbo train 422'd: SDXL checkpoints live at
/storetank/arbo/models/checkpoints/ (the 2026-06-13 move to the 1.8TB
/storetank volume), which wasn't in ALLOWED_MODEL_ROOTS — the old roots
predated the move (/worktank/models is gone, /worktank/comfyui host path
is empty; ComfyUI mounts /storetank/arbo/models -> /basedir/models inside
its container). Allowlist /storetank/arbo/models (llmuser-readable,
world-readable tree), drop the two stale roots. Regression test added (15 green).
comfy-dev cross-check: Sindra v1/v2 used alpha=dim/2 (0.5 LoRA scaling),
which produced the validated likeness; the initial alpha=dim (1.0) was a
stronger, unvalidated default. Align the default to the proven value
(operator/per-request can still override). Tests updated (14 green).
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.
vh