# Vacuum Wall — Agent Instructions

## What This Is

SSL proxy / firewall appliance. Python 3 Flask WebUI behind nginx reverse proxy.
Deploys on Debian 13 (trixie). Target system: `/home/wall/vacuum-wall`.

## Architecture

```
Client ──→ nginx (SSL + basic auth) ──→ Flask (127.0.0.1:9090)
Flask ──→ lib/*.py ──→ sudo <cmd> ──→ system service
```

- `webui/server.py` — Flask app entry point. **Only** file that creates the `app`.
- `webui/api/*.py` — Flask blueprints, one per subsystem. Routes prefix `/api/<subsystem>/`.
- `lib/*.py` — Backend modules. Wrap system commands via `subprocess.run(["sudo", ...])`.
- `data/` — Declarative JSON configs (source of truth). Generated `.conf` in `data/nginx/sites-enabled/`.
- `system/` — System file templates. `systemd/` (service units installed to `/etc/systemd/system/`), `sudoers.d/`, `nginx/`.

Project uses `.venv`. Install deps with `pip install -e .` (from `pyproject.toml`). `__init__.py` files in `webui/` and `lib/` are intentionally empty — no `sys.path` boilerplate needed.

## Fixed Path

Every module hardcodes `/home/wall/vacuum-wall`. Changing it requires updating `lib/*.py`, `system/systemd/*.service`, `install.sh`, and `system/sudoers.d/vacuum-wall`.

## Local Dev

```bash
.venv/bin/python webui/server.py          # binds 127.0.0.1:9090
```

In production the systemd unit runs as the `vacuum-wall` system user (`NoNewPrivileges`, `ProtectSystem=strict`, loopback-only networking).

## Blueprint ↔ lib Mapping (Naming Is Not 1:1)

| Blueprint             | URL prefix        | Backend module   |
|-----------------------|-------------------|------------------|
| `webui/api/firewall`  | `/api/firewall/`  | `lib.firewall`   |
| `webui/api/dhcp`      | `/api/dhcp/`      | `lib.dnsmasq`    |
| `webui/api/proxy`     | `/api/proxy/`     | `lib.nginx`      |
| `webui/api/certs`     | `/api/certs/`     | `lib.acme`       |
| `webui/api/wireguard` | `/api/wireguard/` | `lib.wireguard`  |

## Privileged Operations

`lib/` modules call `sudo` for everything that touches system services. Whitelist is `system/sudoers.d/vacuum-wall`.

Pattern for mutations: write JSON → render native config → `sudo <cmd>` to apply.
Adding a new privileged command requires a sudoers entry **and** the `lib/` code.

## API Response Contract

- Success: `{"ok": true, "data": <value>}` — helper `_ok(data)`
- Error: `{"ok": false, "error": "msg"}` — helper `_error(msg, code=400)`
- HTTP codes: `400` bad request, `404` not found, `500` internal failure
- Full spec: `docs/api.md`

## Page Routes vs API

`server.py` serves HTML pages with Jinja templates. All data is wrapped in `_safely(fn, default)` so page routes never 500 — they render with fallback values instead.

## Deploy

`install.sh` is the single deploy script. Run as root, requires `MGMT_DOMAIN`, `MGMT_PASS`, `ACME_EMAIL` env vars.

## Lint and Tests

**Linter / formatter:** Ruff (`ruff check` + `ruff format`). Config in `pyproject.toml` under `[tool.ruff]`.

**Tests:** pytest in `tests/`. Run with `python -m pytest`. Tests mock out subprocess calls (firewalld, acme.sh, WireGuard, nginx, dnsmasq) — no system services required.

```bash
.venv/bin/ruff check lib/ webui/ tests/   # lint
.venv/bin/ruff format lib/ webui/ tests/   # format
.venv/bin/python -m pytest tests/ -v       # test (154 tests)
```

Install dev tooling with `pip install -e ".[dev]"`.

## Docs

`docs/` contains the authoritative reference. `docs/architecture.md` covers request flow, zone model, and data directory layout in detail.