# System Stats Daemon

An Elixir application that runs as a systemd daemon to:
1. Publish system stats to MQTT every 30 seconds
2. Listen for commands over MQTT and log them to syslog

## Configuration

Edit `config/config.exs` to configure MQTT connection:

```elixir
config :system_stats_daemon, SystemStatsDaemon.MqttClient,
  host: "localhost",
  port: 1883,
  client_id: "system_stats_daemon",
  username: nil,
  password: nil,
  stats_topic: "system/stats",
  command_topic: "system/commands",
  publish_interval: 30_000
```

## Building

```bash
mix deps.get
mix compile
```

## Running

```bash
# Development
mix run --no-halt

# Production release
MIX_ENV=prod mix release
_build/prod/rel/system_stats_daemon/bin/system_stats_daemon start
```

## Systemd Installation

1. Build production release
2. Copy binary to `/usr/local/bin/`
3. Copy `system_stats_daemon.service` to `/etc/systemd/system/`
4. Enable and start:

```bash
sudo systemctl enable system_stats_daemon
sudo systemctl start system_stats_daemon
```

## Features

- Publishes "Hello world" stats every 30 seconds to `system/stats` topic
- Listens on `system/commands` topic and logs received messages
- Configurable MQTT connection settings
- Runs as systemd daemon with auto-restart
- Logs to system journal