# beszel

Lightweight monitoring — CPU, memory, disk, network, and per-container stats for every Docker host, with alerts over email/webhook. Pairs with Dozzle (logs) on the same server.

**Deploys to:**
- **ana-docker** (hub + local agent) — UI at `http://10.250.50.70:8090`
- **ana-ml2** (agent only) — listens on `10.250.50.54:45876`
- **nh3-docker** (agent only, cross-site) — listens on `10.100.50.40:45876`
- **corviduo-dev** (agent only) — listens on `10.250.50.152:45876`. Compose at `/home/vh/docker/compose/beszel/` (not `/opt/docker/compose/` — see `servers/corviduo-dev/README.md` for why)

Same compose.yaml on each host. Per-host `.env` sets `COMPOSE_PROFILES` to bring up the right combination. Each agent host is added individually in the hub UI.

## How hub ↔ agent auth works

Beszel uses SSH-key-based auth: the hub generates its own keypair on first boot, and each agent must be seeded with the hub's **public key** via the `KEY` env var. Agents listen on a port (default 45876); the hub pulls metrics by connecting to them with that key.

Operator flow on first deploy:

1. Bring up the **hub** on ana-docker with `BESZEL_HUB_KEY=` blank and the agent profile disabled.
2. Open the UI, create the admin account, click **Add System** — Beszel shows the public key.
3. Copy the key into `BESZEL_HUB_KEY` in the `.env` on both hosts.
4. Re-deploy the hub with `COMPOSE_PROFILES=hub,agent` to add the local agent; deploy the agent on ana-ml2.
5. Back in the UI, **Add System** with `host=127.0.0.1 port=45876` (local) and `host=10.250.50.54 port=45876` (ana-ml2).

## Deploy — hub + local agent (ana-docker)

```bash
ssh ana-docker
sudo mkdir -p /opt/docker/compose/beszel
sudo chown $USER /opt/docker/compose/beszel
cd /opt/docker/compose/beszel

# scp compose.yaml + .env.example, then:
cp .env.example .env
# First pass — hub only, no key yet:
#   COMPOSE_PROFILES=hub
#   BESZEL_PORT=8090
docker compose up -d

# Open http://10.250.50.70:8090 → create admin → click "Add System" →
# copy the displayed public key into BESZEL_HUB_KEY.

# Second pass — add the local agent:
#   COMPOSE_PROFILES=hub,agent
#   BESZEL_EXTRA_FS=/mnt/backup,/mnt/compose
docker compose up -d
```

## Deploy — agent (ana-ml2)

```bash
ssh ana-ml2
sudo mkdir -p /opt/docker/compose/beszel
sudo chown $USER /opt/docker/compose/beszel
cd /opt/docker/compose/beszel

# scp the same compose.yaml + .env.example, then:
cp .env.example .env
# Edit to:
#   COMPOSE_PROFILES=agent
#   BESZEL_HUB_KEY=<same key as the hub>
#   BESZEL_EXTRA_FS=/tank

docker compose up -d
docker compose logs -f
```

Then in the hub UI, **Add System** with `host=10.250.50.54`, `port=45876`.

## Verify

```bash
# Hub health
curl -s http://10.250.50.70:8090/api/health

# Agent reachable
ssh ana-docker 'nc -zv 10.250.50.54 45876'

# Local agent reachable from hub container
docker exec beszel nc -zv host.docker.internal 45876
```

## Sizing / impact

The agent is ~10 MB RAM and negligible CPU — runs fine alongside anything on ana-ml2 including GPU workloads. Host-mode networking means it has no port conflicts with other stacks as long as `BESZEL_AGENT_PORT` stays unique.

## Alerts

Configured inside the hub UI (Settings → Notifications). Supports email (SMTP), Gotify, ntfy, Discord, Slack, and generic webhooks. Alert rules attach to per-system or global thresholds (CPU, memory, disk, container down, etc.).