# spark-control

A browser-based control panel for a dual-DGX-Spark vLLM cluster. Designed to run as a [StartOS 0.4](https://docs.start9.com/packaging/0.4.0.x/) package on a Start9 server on the same LAN as the Sparks.

## What it does

- Shows which LLM is currently loaded on the cluster (`:8888/v1/models`).
- Click to swap to a different model — stops the current one, launches the new one, streams logs to the UI until `Application startup complete.` appears.
- Surfaces health for Parakeet (STT, `:8000`) and Magpie (TTS, `:9000`) on Spark 2.

## Architecture

```
[Browser/phone] ──► [StartOS reverse proxy] ──► [spark-control container]
                                                       │  (SSH over LAN)
                                                       ▼
                                                  [Spark 1] ──► launch-cluster.sh
                                                       │
                                                       ▼
                                                  [Spark 2]
```

Two layers in this repo:

- `image/` — a self-contained FastAPI app + static UI. Runs anywhere with `uvicorn` and an SSH client. Useful for development.
- `package/` — a thin StartOS 0.4 wrapper that packages the image, exposes the UI on the LAN, and gives the user actions to configure SSH access to the Sparks.

## Quick start (local dev, no StartOS yet)

```bash
cd image
python3 -m venv .venv && source .venv/bin/activate
pip install -e .
export SPARK1_HOST=<spark-1-ip>
export SPARK1_USER=<spark-user>
export SPARK2_HOST=<spark-2-ip>
export SPARK2_USER=<spark-user>
export SSH_KEY_PATH="$HOME/Library/Application Support/NVIDIA/Sync/config/nvsync.key"
uvicorn app.server:app --host 0.0.0.0 --port 9999 --reload
```

Open <http://localhost:9999>.

> **Note:** use the **IP** `<spark-1-ip>` for Spark 1, not `<spark-1-host>.local`. mDNS resolves to IPv6 first and `httpx` hangs on it because vLLM only binds IPv4.

## Build the StartOS package

```bash
cd package
npm i        # one-time
make x86     # produces spark-control_x86_64.s9pk (~55 MB)
```

Requires [`start-cli`](https://docs.start9.com/latest/developer-guide/sdk/installing-the-sdk), Node ≥ 22, Docker. The build runs `tsc` + `ncc` for the TS bundle, then `docker build` on `image/Dockerfile`, then `start-cli s9pk pack` to produce the `.s9pk`.

To sideload onto your Start9: `make install` (needs `host:` set in `~/.startos/config.yaml`), or upload the `.s9pk` via the Start9 web UI's sideload feature.

## Post-install setup (one-time per Start9 install)

1. Open the Spark Control service → **Actions** → **Show Public Key** → copy the line.
2. SSH to each Spark and append the line to `~/.ssh/authorized_keys` for the `<spark-user>` user.
3. **Actions** → **Configure Sparks** → enter `<spark-1-ip>` / `<spark-user>` for Spark 1 and `<spark-2-ip>` / `<spark-user>` for Spark 2.
4. Start the service. Open the Web UI — current model + health should show within ~5 s.

## Repo layout

- `image/` — Docker image source (FastAPI app + `models.yaml`)
- `package/` — StartOS 0.4 package source
- `runbook.md` — operating notes
- `known-issues.md` — known quirks and workarounds
- `LICENSE` — MIT

## Status

**v0.1** — local-only, single-cluster, no auth (trusts LAN). Five LLMs in the catalog: qwen3-vl (cluster), gemma4, qwen36, plus two legacy entries. Magpie surfaces red until its container is fixed.

v0.2 backlog (in `runbook.md` / commits): Parakeet/Magpie lifecycle controls, configurable flag tiers in UI, Open WebUI integration, magpie-tts fix.