mqtt-connector

mqtt-connector

This is an MQTT connector for OpenFaaS.

About

Once configured and deployed it will deliver messages from selected topics to OpenFaaS functions.

There are various other connectors available for OpenFaaS which form "triggers" for event-driven architectures.

Prior work:

This is inspired by prior work by Alex Ellis: Collect, plot and analyse sensor readings from your IoT devices with OpenFaaS

Component parts:

• connector-sdk from OpenFaaS
• The Eclipse provides a test broker
• Eclipse's paho.mqtt.golang package provides the connection to MQTT.

Deploy in-cluster with Kubernetes

See helm chart for deployment instructions. Then continue at "Test the connector".

export TAG=0.3.1

make build push

Deploy out of cluster

go build

export GATEWAY_PASSWORD=""
export BROKER="tcp://test.mosquitto.org:1883"
export TOPIC="openfaas-sensor-data"

./mqtt-connector --gateway http://127.0.0.1:8080 \
  --broker $BROKER \
  --gw-username admin \
  --gw-password $GATEWAY_PASSWORD \
  --topic $TOPIC

Deploy a function:

faas-cli deploy --name echo --image ghcr.io/openfaas/alpine:latest \
  --fprocess=cat \
  --annotation topic="openfaas-sensor-data"

Test the connector

Annotate a function with the annotation topic: $TOPIC <- where $TOPIC is the MQTT topic you care about.

2019/12/03 16:43:26 Topic: topic        Broker: tcp://test.mosquitto.org:1883
2019/12/03 16:43:29 Invoking (http://192.168.0.35:8080) on topic: "topic", value: "{\"sensor\": \"s1\", \"humidity\": \"52.09\", \"temp\": \"23.200\", \"ip\": \"192.168.0.40\", \"vdd33\": \"65535\", \"rssi\": -45}"
2019/12/03 16:43:29 Invoke function: print-out
Send: "{\"sensor\": \"s1\", \"humidity\": \"52.09\", \"temp\": \"23.200\", \"ip\": \"192.168.0.40\", \"vdd33\": \"65535\", \"rssi\": -45}"
2019/12/03 16:43:29 connector-sdk got result: [200] topic => print-out (24) bytes
[200] topic => print-out
{"temperature":"23.200"}
2019/12/03 16:43:29 tester got result: [200] topic => print-out (24) bytes

This data was generated on the topic topic by my NodeMCU device which publishes sensor data.

A node12 function named print-out returned the temperature as reported.

License

MIT