Trunk Recorder MQTT Statistics Plugin

This is a plugin for Trunk Recorder that publish the current statistics over MQTT. External programs can use the MQTT messages to display what is going on.

Install

1. Build and install the current version of Trunk Recorder following these instructions. Make sure you do a sudo make install at the end to install the Trunk Recorder binary and libaries systemwide. The plugin will be built against these libraries.

2. Now, install the Paho MQTT C & C++ Libraries. The full documentation for that is here... but the basic commands are as follows:

Install Paho MQTT C

git clone https://github.com/eclipse/paho.mqtt.c.git
cd paho.mqtt.c
git checkout v1.3.8

cmake -Bbuild -H. -DPAHO_ENABLE_TESTING=OFF -DPAHO_BUILD_STATIC=ON  -DPAHO_WITH_SSL=ON -DPAHO_HIGH_PERFORMANCE=ON
sudo cmake --build build/ --target install
sudo ldconfig

Install Paho MQTT C++

git clone https://github.com/eclipse/paho.mqtt.cpp
cd paho.mqtt.cpp

cmake -Bbuild -H. -DPAHO_BUILD_STATIC=ON  -DPAHO_BUILD_DOCUMENTATION=TRUE -DPAHO_BUILD_SAMPLES=TRUE
sudo cmake --build build/ --target install
sudo ldconfig

3. Build and install the plugin:

mkdir build
cd build
cmake ..
sudo make install

Configure

Key	Required	Default Value	Type	Description
broker	✓	tcp://localhost:1883	string	The URL for the MQTT Message Broker. It should include the protocol used: tcp, ssl, ws, wss and the port, which is generally 1883 for tcp, 8883 for ssl, and 443 for ws.
topic	✓		string	This is the base topic to use. The plugin will create subtopics for the different types of status messages.
username			string	If a username is required for the broker, add it here.
password			string	If a password is required for the broker, add it here.

Plugin Object Example

See the included config.json as an example of how to load this plugin.

    "plugins": [
    {
        "name": "example plugin",
        "library": "libmqtt_statistics_plugin.so",
        "broker": "tcp://io.adafruit.com:1883",
        "topic": "robotastic/feeds",
        "username": "robotastic",
        "password": "" 
    }]

Mosquitto MQTT Broker

This should work with any MQTT Broker, but I have been testing locally with Mosquitto. The Mosquitto MQTT is an easy way to have a local MQTT broker. It can be installed from a lot of package managers.

Starting it on a Mac:

/opt/homebrew/sbin/mosquitto -c /opt/homebrew/etc/mosquitto/mosquitto.conf