MQTT

The MQTT input plugin, allows to retrieve messages/data from MQTT control packets over a TCP connection. The incoming data to receive must be a JSON map.

Configuration Parameters

The plugin supports the following configuration parameters:

Key	Description	Default
Listen	Listener network interface.	0.0.0.0
Port	TCP port where listening for connections.	1883
Payload_Key	Specify the key where the payload key/value will be preserved.	none
Threaded	Indicates whether to run this input in its own thread.	false

Getting Started

In order to start listening for MQTT messages, you can run the plugin from the command line or through the configuration file:

Command Line

Since the MQTT input plugin let Fluent Bit behave as a server, we need to dispatch some messages using some MQTT client, in the following example mosquitto tool is being used for the purpose:

$ fluent-bit -i mqtt -t data -o stdout -m '*'
Fluent Bit v1.x.x
* Copyright (C) 2019-2020 The Fluent Bit Authors
* Copyright (C) 2015-2018 Treasure Data
* Fluent Bit is a CNCF sub-project under the umbrella of Fluentd
* https://fluentbit.io

[2016/05/20 14:22:52] [ info] starting engine
[0] data: [1463775773, {"topic"=>"some/topic", "key1"=>123, "key2"=>456}]

The following command line will send a message to the MQTT input plugin:

$ mosquitto_pub  -m '{"key1": 123, "key2": 456}' -t some/topic

Configuration File

In your main configuration file append the following Input & Output sections:

[INPUT]
    Name   mqtt
    Tag    data
    Listen 0.0.0.0
    Port   1883

[OUTPUT]
    Name   stdout
    Match  *