# Remote Observers

Other operators can run their own [meshcore-packet-capture](https://github.com/agessaman/meshcore-packet-capture) instance and publish decoded packets to your MeshCore Hub. They can also optionally contribute to the LetsMesh and MeshRank networks.

This document covers the local packet-capture observer (the `observer` compose profile) and the remote-observer contribution flow. The `PACKETCAPTURE_*` and `SERIAL_PORT` variables that configure the external capture image are documented at the bottom of this page; for everything else see [configuration.md](configuration.md).

> **Prerequisite:** Your MQTT broker must be accessible to remote observers. In production, this means exposing the WebSocket listener via a reverse proxy with TLS (e.g., `wss://mqtt.example.com/mqtt`).

> **Restricting which observers are accepted:** because anyone with broker access can publish as an observer, Hub operators can gate ingestion by observer public key using `OBSERVER_ALLOWLIST` / `OBSERVER_DENYLIST`. See [configuration.md → Observer Ingestion Filters](configuration.md#observer-ingestion-filters).

## Example: Contribute to MeshCore Hub, LetsMesh, and MeshRank

A ready-made Docker Compose setup is provided in `contrib/packetcapture/`. Download it and configure:

```bash
mkdir meshcore-observer && cd meshcore-observer

wget https://raw.githubusercontent.com/ipnet-mesh/meshcore-hub/main/contrib/packetcapture/docker-compose.yml
wget https://raw.githubusercontent.com/ipnet-mesh/meshcore-hub/main/contrib/packetcapture/.env.example

cp .env.example .env
```

Edit `.env` and update the following variables:

| Variable | Description |
|----------|-------------|
| `SERIAL_PORT` | Device path for your MeshCore companion device (e.g. `/dev/ttyUSB0`, or `/dev/serial/by-id/...` for a stable path) |
| `IATA` | 3-letter area code for your location (e.g. `STN`, `SEA`) |
| `ORIGIN` | Observer identifier (default: `observer`) |
| `IPNET_ENABLE` | Set `true` to contribute packets to IPNet MeshCore Hub (default: `true`) |
| `LETSMESH_ENABLE` | Set `true` to contribute to LetsMesh (default: `false`) |
| `LETSMESH_REGION` | LetsMesh region: `eu` or `us` (default: `eu`) |
| `MESHRANK_ENABLE` | Set `true` to contribute to MeshRank (default: `false`) |
| `MESHRANK_UPLINK_KEY` | Your MeshRank uplink key (required if MeshRank enabled) |
| `CUSTOM_ENABLE` | Set `true` to publish to a custom MQTT broker (default: `false`) |
| `CUSTOM_MQTT_SERVER` | Custom MQTT broker hostname |
| `CUSTOM_MQTT_PORT` | Custom MQTT broker port (default: `8883`) |
| `CUSTOM_MQTT_USE_TLS` | `true` for TLS, `false` for plain (default: `true`) |
| `CUSTOM_MQTT_USERNAME` | Username for custom broker auth |
| `CUSTOM_MQTT_PASSWORD` | Password for custom broker auth |

Then start the observer:

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

> **Local network (no TLS):** Set `CUSTOM_MQTT_SERVER` to the Hub's LAN IP (e.g. `192.168.1.100`), `CUSTOM_MQTT_PORT=1883`, and `CUSTOM_MQTT_USE_TLS=false`.

## Packet Capture Settings

The variables below configure the external **meshcore-packet-capture** image (`ghcr.io/agessaman/meshcore-packet-capture`), which is run by the `observer` compose profile. They are *not* consumed by MeshCore Hub itself — they are listed here because they live in the same `.env` and are needed by operators running an observer. See the [meshcore-packet-capture documentation](https://github.com/agessaman/meshcore-packet-capture) for full details.

### Device

| Variable | Default | Description |
|----------|---------|-------------|
| `SERIAL_PORT` | `/dev/ttyUSB0` | Serial port for the packet-capture device (typically `/dev/ttyUSB[0-9]` or `/dev/ttyACM[0-9]` on Linux) |
| `PACKETCAPTURE_IATA` | `LOC` | 3-letter IATA airport/area code used in LetsMesh topic templates |
| `PACKETCAPTURE_ORIGIN` | _(device name)_ | Observer display name (defaults to the device name from the MeshCore connection) |
| `PACKETCAPTURE_IMAGE_VERSION` | `latest` | Docker image tag for the packet-capture image |

### Connection behaviour

| Variable | Default | Description |
|----------|---------|-------------|
| `PACKETCAPTURE_TIMEOUT` | `30` | Connection timeout in seconds |
| `PACKETCAPTURE_MAX_CONNECTION_RETRIES` | `5` | Max device-connection retries |
| `PACKETCAPTURE_CONNECTION_RETRY_DELAY` | `5` | Seconds between device-connection retries |
| `PACKETCAPTURE_HEALTH_CHECK_INTERVAL` | `30` | Seconds between health checks |
| `PACKETCAPTURE_ADVERT_INTERVAL_HOURS` | `11` | Send flood adverts at this interval in hours (`0` = disabled) |
| `PACKETCAPTURE_RF_DATA_TIMEOUT` | `15.0` | RF data cache timeout in seconds |

### MQTT reconnection

| Variable | Default | Description |
|----------|---------|-------------|
| `PACKETCAPTURE_MAX_MQTT_RETRIES` | `5` | Max MQTT reconnection attempts |
| `PACKETCAPTURE_MQTT_RETRY_DELAY` | `5` | Seconds between MQTT reconnection attempts |
| `PACKETCAPTURE_EXIT_ON_RECONNECT_FAIL` | `true` | Exit the process when MQTT reconnection fails |

### LetsMesh / custom MQTT brokers

The observer can publish to up to three MQTT brokers in parallel. Broker 3 is wired to the Hub's own `MQTT_*` settings by default.

| Variable | Default | Description |
|----------|---------|-------------|
| `PACKETCAPTURE_MQTT1_ENABLED` | `false` | Publish to LetsMesh US |
| `PACKETCAPTURE_MQTT1_SERVER` | `mqtt-us-v1.letsmesh.net` | Broker 1 hostname |
| `PACKETCAPTURE_MQTT1_PORT` | `443` | Broker 1 port |
| `PACKETCAPTURE_MQTT1_USE_TLS` | `true` | Use TLS for broker 1 |
| `PACKETCAPTURE_MQTT1_USE_AUTH_TOKEN` | `true` | Use JWT auth token for broker 1 |
| `PACKETCAPTURE_MQTT1_TOKEN_AUDIENCE` | `mqtt-us-v1.letsmesh.net` | JWT audience claim for broker 1 |
| `PACKETCAPTURE_MQTT1_KEEPALIVE` | `120` | Keepalive (seconds) for broker 1 |
| `PACKETCAPTURE_MQTT2_ENABLED` | `false` | Publish to LetsMesh EU |
| `PACKETCAPTURE_MQTT2_SERVER` | `mqtt-eu-v1.letsmesh.net` | Broker 2 hostname |
| `PACKETCAPTURE_MQTT2_PORT` | `443` | Broker 2 port |
| `PACKETCAPTURE_MQTT2_USE_TLS` | `true` | Use TLS for broker 2 |
| `PACKETCAPTURE_MQTT2_USE_AUTH_TOKEN` | `true` | Use JWT auth token for broker 2 |
| `PACKETCAPTURE_MQTT2_TOKEN_AUDIENCE` | `mqtt-eu-v1.letsmesh.net` | JWT audience claim for broker 2 |
| `PACKETCAPTURE_MQTT2_KEEPALIVE` | `120` | Keepalive (seconds) for broker 2 |
| `PACKETCAPTURE_MQTT3_ENABLED` | `true` | Publish to the local Hub MQTT broker (wired to `MQTT_*`) |
| `PACKETCAPTURE_MQTT3_KEEPALIVE` | `60` | Keepalive (seconds) for broker 3 |
