Forwarding data from IoT devices to Zabbix

About

This tutorial describes how to receive measurement or metric values in JSON format, for example from IoT devices running Tasmota or ESPEasy, and converge them into Zabbix, using mqttwarn’s Zabbix service plugin.

Note

This tutorial has been conceived in the time of the advent of the venerable ESP8266 processors, where networking with embedded devices was made affordable, and projects like Battery Powered ESP8266 IoT – Temperature Sensor or Battery Powered ESP8266 WiFi Temperature and Humidity Logger have been conceived and demonstrated their applications.

Configuration

As an example, let’s consider we wish to capture temperature and humidity data from an MQTT topic like tele/<device>/<metric>, for example tele/bathroom/temperature and tele/bathroom/humidity.

In order to implement it, use the following mqttwarn configuration file, and the accompanying user-defined functions file.

[defaults]
functions = 'mqttwarn-zabbix-iot.py'
launch = zabbix

[config:zabbix]
targets = {
    't1'  : [ 'localhost', 10051 ],
  }

[tele/#]
alldata = decode_for_zabbix()
targets = zabbix:t1

def decode_for_zabbix(topic, data, srv=None):
    status_key = None

    # the first part (part[0]) is always tele
    # the second part (part[1]) is the device, the value comes from
    # the third part (part[2]) is the name of the metric (e.g. temperature/humidity/voltage...)
    parts = topic.split('/')
    client = parts[1]
    key = parts[2]

    return dict(client=client, key=key, status_key=status_key)

To complete the setup, we need to create a host (or more hosts) in Zabbix with the corresponding device name that delivers the value ((part[1]) in udf.py). At last, we need to create a Zabbix trapper item on this host.

Name: <trapper name>    # Anything you like, I named it `mqtt_temp`. 
Type: zabbix_trapper
Key:  <metric name>     # Must correspond with the third part (part[2]) of the decoded MQTT topic, for example `temperature`.
Type: numeric (float)

Usage

Using three terminal sessions, you can exercise the example interactively. First, let’s start the Mosquitto MQTT broker.

docker run --name=mosquitto -it --rm --publish=1883:1883 eclipse-mosquitto:2.0 mosquitto -c /mosquitto-no-auth.conf

Let’s acquire the configuration assets, and start mqttwarn.

wget https://github.com/mqtt-tools/mqttwarn/raw/main/examples/zabbix-iot/mqttwarn-zabbix-iot.ini
wget https://github.com/mqtt-tools/mqttwarn/raw/main/examples/zabbix-iot/mqttwarn-zabbix-iot.py
mqttwarn --config-file=mqttwarn-zabbix-iot.ini

Now, when publishing a metric value to the designated MQTT topic, mqttwarn will provision a Zabbix host and trapper, and submit the metric to it.

echo '42.42' | mosquitto_pub -t 'tele/bathroom/temperature' -l

After publishing a value to the topic, for example tele/bathroom/temperature, you should be able to see this value in Zabbix at the host named bathroom, with the item name temperature.