Thursday, February 11, 2016

Sending IoT sensor data to Hawkular-Metrics via MQTT

The other day I was writing about 'RHQ-Metrics and Grafana' and was describing how you can incorporate data from other system management agents.

Fast forward a bit and Raider is now called Twix and RHQ-Metrics has morphed to Hawkular-Metrics under the umbrella.

Recently I have also been playing with Arduino and Co. and got myself also an Adafruit Huzzah ESP8266 board. This is a breakout board with the ESP8266 microprocessor on, that has a bunch of IO pins and built-in WiFi. With the default firmware it is programmed in Lua.

Huzzah on Breakout board
Huzzah on breakout board

While one can program the ESP from the Arduino IDE, I thought to give Lua a try (also to get a feel for the difference to the WiPy, that also comes with Python as a high level language). What is nice with the ESP and the NodeMCU firmware is that it already comes with support for networking, 1-wire, MQTT and more out of the box.

To get started I took the hello-world of IoT-sensors and hooked up a DS18B20 OneWire thermo sensor (for those old enough, I did that in the past with RHQ) up to the ESP and then have this communicate to a MQTT Broker (mosquitto).

Hawkular Metrics IOT
Setup diagram

As said before we have with Ptrans a universal protocol translator that can be used to feed data from collected, ganglia and others into Hawkular-Metrics. I've taken that and added support for MQTT (in my personal repo for now). Ptrans will now connect to a broker and listen on the '/hawkular/metrics' topic for data that needs to be in graphite format like

path value [timestamp_in_s]

The timestamp is optional, as in my case I was not able to get any real time clock data from the micro controller (there seem to be variants that have a clock on board).

To see the data that is coming from the device I can just run

$ mosquitto_sub  -t /hawkular/+
16617927: 24.625
16617927: 23.9375
16617927: 23.8750

So here NodMCU with ID 16617927 and thermo sensor is reporting around 24 deg Celsius.

I will post more on the topic in a laster posting.


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