zabbix

The zabbix service serves two purposes:

1. it can create a Zabbix host on-the-fly via Low-level Discovery (LLD)
2. it can send an item/value pair to a Zabbix trapper

The target and topic configuration look like this:

[config:zabbix]
; Zabbix host with MQTT host discovery template attached
;host = <zabbix host>

targets = {
            # Trapper address   port
    't1'  : [ '172.16.153.110', 10051 ],
  }

[zabbix/clients/+]
alldata = ZabbixData()
targets = zabbix:t1

[zabbix/item/#]
alldata = ZabbixData()
targets = zabbix:t1

A transformation function in alldata is required to extract the client's name from the topic, and for #1, to define a "host alive" item key in Zabbix.

# If the topic begins with zabbix/clients we have a host going up or down
# e.g. "zabbix/clients/jog03" -> "jog03"
#   extract client name (3rd part of topic)
#   set status key (e.g. 'host.up') to publish 1/0 on it (e.g during LWT)
#
# if the topic starts with zabbix/item we have an item/value for the host
# e.g. "zabbix/item/jog03/time.stamp" -> "jog03"
#   extract client name (3rd part of topic)
#

def ZabbixData(topic, data, srv=None):
    client = 'unknown'
    key = None
    status_key = None

    parts = topic.split('/')
    client = parts[2]

    if topic.startswith('zabbix/clients/'):
        status_key = 'host.up'

    if topic.startswith('zabbix/item/'):
        key = parts[3]

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

The blog post Zabbix meets MQTT explains a bit of the background.

---

Another example:

We want to receive temperature and humidity values from ESP8266 devices, for instance such kind of IOT-devices: http://homecircuits.eu/blog/battery-powered-esp8266-iot-logger/ or https://github.com/tzapu/DeepSleepDHT22

As Firmware we can use: https://github.com/arendst/Sonoff-Tasmota or https://github.com/letscontrolit/ESPEasy

then we wish to capture all data from mqtt topic like tele/device/metric, for instance: tele/bathroom/temperature

To archieve this we add following settings to /opt/mqttwarn/mqttwarn.ini:

functions = 'samplefuncs'

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



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

in the file /opt/mqttwarn/samplefuncs.py, we add:

def ZabbixData(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)

After this, we need to create a host (or more hosts) in zabbix with the corresponding devicename that delivers the value ((part[1]) in samplefuncs.py). At last we need to create an _item _inside the new created host:

Name: You are free in create name for it, I named it mqtt_temp.

Type: zabbix_trapper.

Key: must correspond with the third part (part[2]) in the delivered mqtt-topic, for instance temperature

Type of information: numeric (float)

That's all! After publishing a value to the topic e.g. tele/bathroom/temperature, you should be able see this value in zabbix at host named "bathroom" with the item "temperature".