Book Image

MQTT Essentials - A Lightweight IoT Protocol

5 (1)
Book Image

MQTT Essentials - A Lightweight IoT Protocol

5 (1)

Overview of this book

This step-by-step guide will help you gain a deep understanding of the lightweight MQTT protocol. We’ll begin with the specific vocabulary of MQTT and its working modes, followed by installing a Mosquitto MQTT broker. Then, you will use best practices to secure the MQTT Mosquitto broker to ensure that only authorized clients are able to publish and receive messages. Once you have secured the broker with the appropriate configuration, you will develop a solution that controls a drone with Python. Further on, you will use Python on a Raspberry Pi 3 board to process commands and Python on Intel Boards (Joule, Edison and Galileo). You will then connect to the MQTT broker, subscribe to topics, send messages, and receive messages in Python. You will also develop a solution that interacts with sensors in Java by working with MQTT messages. Moving forward, you will work with an asynchronous API with callbacks to make the sensors interact with MQTT messages. Following the same process, you will develop an iOS app with Swift 3, build a website that uses WebSockets to connect to the MQTT broker, and control home automation devices with HTML5, JavaScript code, Node.js and MQTT messages
Table of Contents (16 chapters)
MQTT Essentials - A Lightweight IoT Protocol
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Configuring TLS client certificate authentication in Mosquitto

Now, we will configure Mosquitto to use TLS client certificate authentication. This way, any client will require the ca.crt file and a client certificate to establish a communication with the Mosquitto server.

In case you are running the Mosquitto server in a Terminal window in macOS or Linux, press CtrlC to stop it. In Windows, stop the appropriate service.

Go to the Mosquitto installation directory and open the mosquitto.conf configuration file.

In macOS, Linux. or Windows, add the following lines at the end of the configuration file:

require_certificate true 

We specified the true value for the require_certificate option to make Mosquitto require a valid client certificate for any client that requests a connection to Mosquitto.

Save the changes to the mosquitto.conf configuration file and launch Mosquitto again. We will use the mosquitto_sub command-line utility included in Mosquitto to generate a simple MQTT client that subscribes...