MQTT Source Connector for Confluent Platform

The Kafka Connect MQTT Source Connector connects to a MQTT broker and subscribes to the specified topics. SSL is supported. For information on how to create SSL keys and certificates, see Creating SSL Keys and Certificates. For the relevant configuration properties, see the MQTT Source Connector configuration reference.

Features

At least once delivery

This connector guarantees that records are delivered to the Kafka topic at least once. If the connector restarts, there may be some duplicate records in the Kafka topic.

Dead Letter Queue

This connector supports the Dead Letter Queue (DLQ) functionality. For information about accessing and using the DLQ, see Confluent Platform Dead Letter Queue.

Configuration Properties

For a complete list of configuration properties for this source connector, see MQTT Source Connector Configuration Properties.

Note

For an example of how to get Kafka Connect connected to Confluent Cloud, see Distributed Cluster.

Usage Notes

If you need to change the topic take a look at the RegexRouter transformation which can be used to change the topic name before it is written to Apache Kafka®.

The output of this connector is an envelope with all of the properties of the incoming message. The body of the message is written to the value as bytes. The key is the topic the message was written to.

Examples

Property-based example

This configuration is used typically along with standalone workers.

 name=MqttSourceConnector1
 connector.class=io.confluent.connect.mqtt.MqttSourceConnector
 tasks.max=1
 mqtt.server.uri=< Required Configuration >
 mqtt.topics=< Required Configuration >

REST-based example

This configuration is used typically along with distributed workers. Write the following json to connector.json, configure all of the required values, and use the command below to post the configuration to one the distributed connect worker(s). Check here for more information about the Kafka Connect REST API

Connect Distributed REST example:

 {
   "config" : {
     "name" : "MqttSourceConnector1",
     "connector.class" : "io.confluent.connect.mqtt.MqttSourceConnector",
     "tasks.max" : "1",
     "mqtt.server.uri" : "< Required Configuration >",
     "mqtt.topics" : "< Required Configuration >"
   }
 }

Use curl to post the configuration to one of the Kafka Connect Workers. Change http://localhost:8083/ the endpoint of one of your Kafka Connect worker(s).

  • Create a new connector:

    curl -s -X POST -H 'Content-Type: application/json' --data @connector.json http://localhost:8083/connectors
    
  • Update an existing connector:

    curl -s -X PUT -H 'Content-Type: application/json' --data @connector.json http://localhost:8083/connectors/MqttSourceConnector1/config