MQTT Server Binding v0.1.0

The MQTT server binding v0.1.0 provides configuration for the connection between a client and an MQTT broker, including session parameters and the Last Will and Testament (LWT).

Overview

This binding object defines the core characteristics of an MQTT connection, such as the client's identity, session persistence, and a fail-safe message (LWT) for ungraceful disconnections.

Server Properties

Property	Type	Required	Description
bindingVersion	string	No	Binding version (defaults to 0.1.0).
clientId	string	No	The client identifier.
cleanSession	boolean	No	Whether the broker should establish a persistent session. Defaults to true.
lastWill	object	No	Last Will and Testament configuration.
keepAlive	integer	No	Keep alive interval in seconds. Defaults to 60.

Property Details

clientId

A unique identifier for the client. A stable clientId is required for persistent sessions.

cleanSession

• true (default): The broker creates a temporary session that is deleted when the client disconnects.
• false: The broker creates a persistent session, storing subscriptions and queued messages for the client across disconnections.

lastWill

An object defining the Last Will and Testament message, which the broker publishes if the client disconnects ungracefully.

• topic (string, required): The topic for the LWT message.
• qos (integer): The QoS for the LWT message.
• message (string): The payload of the LWT message.
• retain (boolean): Whether the LWT message should be retained.

keepAlive

The maximum interval in seconds that the client and broker can go without sending a message.

Example

This server configuration defines a client with a Last Will and a persistent session.

servers:
  device-farm:
    url: mqtt://api.example.com
    protocol: mqtt
    bindings:
      mqtt:
        bindingVersion: '0.1.0'
        clientId: 'temp-sensor-123'
        cleanSession: false
        keepAlive: 60
        lastWill:
          topic: /devices/status
          qos: 1
          message: '{"deviceId": "temp-sensor-123", "status": "offline"}'
          retain: true

Changelog

Version 0.1.0

• Initial legacy release of the MQTT server binding.
• Added clientId, cleanSession, lastWill, and keepAlive properties.