# NetMonitor — Docker Image Build & Deploy Guide

Clean, reproducible image: **Ubuntu 26.04 + sshd + Python 3 + NetMonitor (empty database)**.
No collected data, no hosts — first boot auto-creates the admin account.

| Item | Value |
|---|---|
| Web UI | `http://<nas-ip>:7080` |
| SSH | `root@<nas-ip>` port **7022** (password = build arg) |
| First login | `sysadmin` / `pas4admin` (change it after first login) |
| App home | `/opt/netmonitor` (logs: `/var/log/netmonitor.log`) |
| Service control | `/etc/init.d/netmonitor {start|stop|restart|status}` |

## 1. Build the image

From the project root (folder containing `Dockerfile`):

```bash
docker build --build-arg ROOT_PASSWORD='ChangeMe-RootPass' -t netmonitor:latest .
```

- `ROOT_PASSWORD` sets the container's SSH root password. **Required** — the build fails without it.
- Needs internet access for `apt` + `pip` (Ubuntu 26.04, python3, openssh-server, Flask, psutil, tplinkrouterc6u, pycryptodome).

## 2. Run the container

```bash
docker run -d --name netmonitor \
  --restart unless-stopped \
  -p 7080:7080 \
  -p 7022:7022 \
  netmonitor:latest
```

- `--restart unless-stopped` → container (and therefore sshd + netmonitor) comes back automatically after DSM reboot or container restart. In the Synology Docker GUI this is the **Autostart** checkbox.
- The entrypoint starts `sshd` and the netmonitor service, then keeps the container alive.
- Different web port on the host? Change the left side, e.g. `-p 80:7080`.
- Different web port inside? `NETMONITOR_PORT=8080` env (or edit `config.json` before build).

## 3. Deploy to another Synology DSM

Pick one path:

### A. Build directly on the target DSM (simplest)
1. Enable SSH on the target DSM: *Control Panel → Terminal & SNMP*.
2. Copy the project folder to the target (from your PC):
   ```bash
   scp -r Net-Monitor root@<target-dsm-ip>:/volume1/docker/
   ```
   (or copy via SMB/File Station to a shared folder)
3. On the target DSM:
   ```bash
   cd /volume1/docker/Net-Monitor
   docker build --build-arg ROOT_PASSWORD='ChangeMe-RootPass' -t netmonitor:latest .
   docker run -d --name netmonitor --restart unless-stopped -p 7080:7080 -p 7022:7022 netmonitor:latest
   ```

### B. Build once, move the image to any DSM
```bash
# on the build machine / DSM:
docker save netmonitor:latest > netmonitor-image.tar

# transfer:
scp netmonitor-image.tar root@<target-dsm-ip>:/volume1/docker/

# on the target DSM:
docker load < /volume1/docker/netmonitor-image.tar
docker run -d --name netmonitor --restart unless-stopped -p 7080:7080 -p 7022:7022 netmonitor:latest
```
> `docker save/load` moves the **image** (reproducible). Avoid `docker export` — that snapshots a live container's filesystem and bakes in its data.

### C. Synology Docker GUI
Possible for *Run* (Containers tab: name, ports, autostart), but the GUI image builder can't `COPY` local app files reliably — use the CLI build (A or B) for the image itself.

## 4. Verify

```bash
docker ps                                   # Up
docker logs netmonitor | head               # "NetMonitor listening on http://0.0.0.0:7080 ..."
ssh root@<nas-ip> -p 7022                   # shell works
ssh root@<nas-ip> -p 7022 "/etc/init.d/netmonitor status"
```

Open `http://<nas-ip>:7080` → login `sysadmin` / `pas4admin` → **Administration → Hosts** → add your SNMP / router hosts.

## 5. Day-2 operations

```bash
docker exec -it netmonitor /etc/init.d/netmonitor restart   # restart app only
docker exec -it netmonitor tail -f /var/log/netmonitor.log  # logs
docker stop netmonitor && docker start netmonitor           # restart container (autostart preserved)
docker rm -f netmonitor                                     # remove (image stays)
```

**Data location:** `/opt/netmonitor/data/netmonitor.db` (SQLite — users, hosts, credentials, metrics).
To keep data across container recreation, mount a volume and copy the DB in once:
```bash
docker run -d --name netmonitor --restart unless-stopped \
  -p 7080:7080 -p 7022:7022 \
  -v /volume1/docker/netmonitor-data:/opt/netmonitor/data \
  netmonitor:latest
# then, if migrating existing data:
docker cp <old-container>:/opt/netmonitor/data/netmonitor.db /volume1/docker/netmonitor-data/
docker exec netmonitor /etc/init.d/netmonitor restart
```

## 6. Image contents (what the build installs)

- Ubuntu 26.04 base, `python3` (3.14), `python3-pip`, `openssh-server` + sftp
- Python deps: `Flask`, `psutil`, `tplinkrouterc6u`, `pycryptodome`
- App: `app.py collector.py db.py router_pollers.py snmp_client.py` + `static/` + `docs/`
- Service: `/etc/init.d/netmonitor` (SysV-style, uses `start-stop-daemon`)
- Entrypoint: starts sshd + netmonitor, keeps container alive