mqtt-connector

About this fork

This repository is a fork of the OpenFaaS MQTT Connector with some features and changes:

• Support for namespace filtering using flusflas/connector-sdk and namespace environment variable.
• Configurable rebuild interval for functions-topics mapping.
• Switch from Go Dep to Go Module.
• Add async-callback-url command argument to set an optional callback URL for asynchronous invocations.
• Fix the behavior with topic subscriptions: before, a default message handler was handling every message on every topic (which was equivalent to a subscription to #). Now, a subscription per topic is created from the comma-separated list of topics, and a non-default handler is used to only handle the messages on the subscribed topics.

Status

This is an MQTT connector for OpenFaaS. 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".

TAG=0.2.0 make build push

Deploy out of cluster

go build

export TOPIC=""
export GATEWAY_PASS=""

./mqtt-connector --gateway http://192.168.0.35:8080 \
  --gw-password $GATEWAY_PASS \
  --broker tcp://test.mosquitto.org:1883 \
  --topic $TOPIC

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.

Custom builds

export NAMESPACE="alexellis2" # Or set your own registry/username
TAG=0.1.1 make build push

License

MIT