MQTT

The MQTT input plugin retrieves messages and 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

Get started

To listen for MQTT messages, you can run the plugin from the command line or through the configuration file.

Command line

The MQTT input plugin lets Fluent Bit behave as a server. Dispatch some messages using a MQTT client. In the following example, the mosquitto tool is being used for the purpose:

Running the following command:

fluent-bit -i mqtt -t data -o stdout -m '*'

Returns a response like the following:

...
[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:

fluent-bit.yaml

pipeline:
  inputs:
    - name: mqtt
      tag: data
      listen: 0.0.0.0
      port: 1883
      
  outputs:
    - name: stdout
      match: '*'

fluent-bit.conf

[INPUT]
  Name   mqtt
  Tag    data
  Listen 0.0.0.0
  Port   1883

[OUTPUT]
  Name   stdout
  Match  *