sentinel/README.md

# Key-IP Sentinel

Key-IP Sentinel is a FastAPI-based reverse proxy that enforces first-use IP binding for model API keys before traffic reaches a downstream New API service.

## Features

- First-use bind with HMAC-SHA256 token hashing, Redis cache-aside, and PostgreSQL CIDR matching.
- Streaming reverse proxy built on `httpx.AsyncClient` and FastAPI `StreamingResponse`.
- Trusted proxy IP extraction that only accepts `X-Real-IP` from configured upstream networks.
- Redis-backed intercept alert counters with webhook delivery and PostgreSQL audit logs.
- Admin API protected by JWT and Redis-backed login lockout.
- Vue 3 + Element Plus admin console for dashboarding, binding operations, audit logs, and live runtime settings.
- Docker Compose deployment with Nginx, app, Redis, and PostgreSQL.

## Repository Layout

```text
sentinel/
├── app/
├── db/
├── nginx/
├── frontend/
├── docker-compose.yml
├── Dockerfile
├── requirements.txt
└── README.md
```

## Runtime Notes

- Redis stores binding cache, alert counters, daily dashboard metrics, and mutable runtime settings.
- PostgreSQL stores authoritative token bindings and intercept logs.
- Archive retention removes inactive bindings from the active table after `ARCHIVE_DAYS`. A later request from the same token will bind again on first use.
- `SENTINEL_FAILSAFE_MODE=closed` rejects requests when both Redis and PostgreSQL are unavailable. `open` allows traffic through.
- Binding rules support `single` (single IP or single CIDR), `multiple` (multiple discrete IPs), and `all` (allow all source IPs).

## Sentinel and New API Relationship

Sentinel and New API are expected to run as **two separate Docker Compose projects**:

- The **Sentinel compose** contains `nginx`, `sentinel-app`, `redis`, and `postgres`.
- The **New API compose** contains your existing New API service and its own dependencies.
- The two stacks communicate through a **shared external Docker network**.

Traffic flow:

```text
Client / SDK
    |
    |  request to Sentinel public endpoint
    v
Sentinel nginx  ->  sentinel-app  ->  New API service  ->  model backend
                         |
                         +-> redis / postgres
```

The key point is: **clients should call Sentinel, not call New API directly**, otherwise IP binding will not take effect.

## Recommended Deployment Topology

Use one external network name for both compose projects. This repository currently uses:

```text
shared_network
```

In the Sentinel compose:

- `sentinel-app` joins `shared_network`
- `nginx` exposes the public entrypoint
- `DOWNSTREAM_URL` points to the **New API service name on that shared network**

In the New API compose:

- The New API container must also join `shared_network`
- The New API service name must match what Sentinel uses in `DOWNSTREAM_URL`

Example:

- New API compose service name: `new-api`
- New API internal container port: `3000`
- Sentinel `.env`: `DOWNSTREAM_URL=http://new-api:3000`

If your New API service is named differently, change `DOWNSTREAM_URL` accordingly, for example:

```text
DOWNSTREAM_URL=http://my-newapi:3000
```

## Local Development

### Backend

1. Install `uv` and ensure Python 3.13 is available.
2. Create the environment and sync dependencies:

```bash
uv sync
```

3. Copy `.env.example` to `.env` and update secrets plus addresses.
4. Start PostgreSQL and Redis.
5. Run the API:

```bash
uv run uvicorn app.main:app --reload --host 0.0.0.0 --port 7000
```

### Frontend

1. Install dependencies:

```bash
cd frontend
npm install
```

2. Start Vite dev server:

```bash
npm run dev
```

The Vite config proxies `/admin/api/*` to `http://127.0.0.1:7000`.

If you prefer the repository root entrypoint, `uv run main.py` now starts the same FastAPI app on `APP_PORT` (default `7000`).

## Dependency Management

- Local Python development uses `uv` via [`pyproject.toml`](/d:/project/sentinel/pyproject.toml).
- Container builds still use [`requirements.txt`](/d:/project/sentinel/requirements.txt) because the Dockerfile is intentionally minimal and matches the delivery requirements.

## Production Deployment

### 1. Create the shared Docker network

Create the external network once on the Docker host:

```bash
docker network create shared_network
```

Both compose projects must reference this exact same external network name.

### 2. Make sure New API joins the shared network

In the **New API** project, add the external network to the New API service.

Minimal example:

```yaml
services:
  new-api:
    image: your-new-api-image
    networks:
      - default
      - shared_network

networks:
  shared_network:
    external: true
```

Important:

- `new-api` here is the **service name** that Sentinel will resolve on the shared network.
- The port in `DOWNSTREAM_URL` must be the **container internal port**, not the host published port.
- If New API already listens on `3000` inside the container, use `http://new-api:3000`.

### 3. Prepare Sentinel environment

1. Copy `.env.example` to `.env`.
2. Replace `SENTINEL_HMAC_SECRET`, `ADMIN_PASSWORD`, and `ADMIN_JWT_SECRET`.
3. Verify `DOWNSTREAM_URL` points to the New API **service name on `shared_network`**.
4. Keep `PG_DSN` aligned with the fixed PostgreSQL container password in `docker-compose.yml`, or update both together.

Example `.env` for Sentinel:

```text
DOWNSTREAM_URL=http://new-api:3000
REDIS_ADDR=redis://redis:6379
REDIS_PASSWORD=
PG_DSN=postgresql+asyncpg://sentinel:password@postgres:5432/sentinel
SENTINEL_HMAC_SECRET=replace-with-a-random-32-byte-secret
ADMIN_PASSWORD=replace-with-a-strong-password
ADMIN_JWT_SECRET=replace-with-a-random-jwt-secret
TRUSTED_PROXY_IPS=172.24.0.0/16
SENTINEL_FAILSAFE_MODE=closed
APP_PORT=7000
ALERT_WEBHOOK_URL=
ALERT_THRESHOLD_COUNT=5
ALERT_THRESHOLD_SECONDS=300
ARCHIVE_DAYS=90
```

Notes:

- `TRUSTED_PROXY_IPS` should match the Docker subnet used by the Sentinel internal network.
- If Docker recreates the compose network with a different subnet, update this value.

### 4. Build the Sentinel frontend bundle

```bash
cd frontend
npm install
npm run build
cd ..
```

This produces `frontend/dist`, which Nginx serves at `/admin/ui/`.

### 5. Confirm Sentinel compose prerequisites

- Build the frontend first. If `frontend/dist` is missing, `/admin/ui/` cannot be served by Nginx.
- Ensure the external Docker network `shared_network` already exists before starting Sentinel.

### 6. Start the Sentinel stack

```bash
docker compose up --build -d
```

Services:

- `http://<host>/` forwards model API traffic through Sentinel.
- `http://<host>/admin/ui/` serves the admin console.
- `http://<host>/admin/api/*` serves the admin API.
- `http://<host>/health` exposes the app health check.

### 7. Verify cross-compose connectivity

After both compose stacks are running:

1. Open `http://<host>:8016/health` and confirm it returns `{"status":"ok"}`.
2. Open `http://<host>:8016/admin/ui/` and log in with `ADMIN_PASSWORD`.
3. Send a real model API request to Sentinel, not to New API directly.
4. Check the `Bindings` page and confirm the token appears with a recorded binding rule.

Example test request:

```bash
curl http://<host>:8016/v1/models \
  -H "Authorization: Bearer <your_api_key>"
```

If your client still points directly to New API, Sentinel will not see the request and no binding will be created.

## Which Port Should Clients Use?

With the current example compose in this repository:

- Sentinel public port: `8016`
- New API internal container port: usually `3000`

That means:

- **For testing now**, clients should call `http://<host>:8016/...`
- **Sentinel forwards internally** to `http://new-api:3000`

Do **not** point clients at host port `3000` if that bypasses Sentinel.

## How To Go Live Without Changing Client Config

If you want existing clients to stay unchanged, Sentinel must take over the **original external entrypoint** that clients already use.

Typical cutover strategy:

1. Keep New API on the shared internal Docker network.
2. Stop exposing New API directly to users.
3. Expose Sentinel on the old public host/port instead.
4. Keep `DOWNSTREAM_URL` pointing to the internal New API service on `shared_network`.

For example, if users currently call `http://host:3000`, then in production you should eventually expose Sentinel on that old public port and make New API internal-only.

The current `8016:80` mapping in [`docker-compose.yml`](/d:/project/sentinel/docker-compose.yml) is a **local test mapping**, not the only valid production setup.

## Admin API Summary

- `POST /admin/api/login`
- `GET /admin/api/dashboard`
- `GET /admin/api/bindings`
- `POST /admin/api/bindings/unbind`
- `PUT /admin/api/bindings/ip`
- `POST /admin/api/bindings/ban`
- `POST /admin/api/bindings/unban`
- `GET /admin/api/logs`
- `GET /admin/api/logs/export`
- `GET /admin/api/settings`
- `PUT /admin/api/settings`

All admin endpoints except `/admin/api/login` require `Authorization: Bearer <jwt>`.

## Key Implementation Details

- `app/proxy/handler.py` keeps the downstream response fully streamed, including SSE responses.
- `app/core/ip_utils.py` never trusts client-supplied `X-Forwarded-For`.
- `app/services/binding_service.py` batches `last_used_at` updates every 5 seconds through an `asyncio.Queue`.
- `app/services/alert_service.py` pushes webhooks once the Redis counter reaches the configured threshold.
- `app/services/archive_service.py` prunes stale bindings on a scheduler interval.

## Suggested Smoke Checks

1. `GET /health` returns `{"status":"ok"}`.
2. A first request with a new bearer token creates a binding in PostgreSQL and Redis.
3. A second request from the same IP is allowed and refreshes `last_used_at`.
4. A request from a different IP is rejected with `403` and creates an `intercept_logs` record, unless the binding rule is `all`.
5. `/admin/api/login` returns a JWT and the frontend can load `/admin/api/dashboard`.