Table Of ContentMQTT Essentials - A Lightweight IoT Protocol
Table of Contents
MQTT Essentials - A Lightweight IoT Protocol
Credits
About the Author
Acknowledgment
About the Reviewer
www.PacktPub.com
Why subscribe?
Customer Feedback
Dedication
Preface
What this book covers
What you need for this book
Who this book is for
Conventions
Reader feedback
Customer support
Downloading the example code
Downloading the color images of this book
Errata
Piracy
Questions
1. Lightweight Messaging with MQTT 3.1.1 and Mosquitto
Understanding convenient scenarios for the MQTT protocol
Working with the publish-subscribe pattern
Working with message filtering
Understanding the MQTT puzzle -- clients, servers, and connections
Installing a Mosquitto broker on Ubuntu Linux
Installing a Mosquitto broker on macOS
Installing a Mosquitto broker on Windows
Subscribing to topics
Publishing messages
Unsubscribing from topics
Working with best practices when creating topics
Understanding wildcards
Learning about the different Quality of Service levels
Working with at least once delivery
Working with exactly once delivery
Test your knowledge
Summary
2. Securing an MQTT Mosquitto Server
Securing a Mosquitto server
Generating a private certificate authority to use TLS with Mosquitto
Creating a certificate for the Mosquitto server
Configuring TLS transport security in Mosquitto
Testing the MQTT TLS configuration with MQTT.fx
Testing the MQTT TLS configuration with MQTT-spy
Creating a certificate for each MQTT client
Configuring TLS client certificate authentication in Mosquitto
Testing the MQTT TLS client authentication with MQTT.fx
Testing the MQTT TLS configuration with MQTT-spy
Forcing the TLS protocol version
Test your knowledge
Summary
3. Controlling a Drone with Python
Understanding the requirements to control a drone with MQTT
Defining the topics and commands
Installing paho-mqtt for Python
Connecting the client to the MQTT server with Python
Understanding callbacks
Subscribing to topics with Python
Creating a class to represent a drone
Receiving messages with Python
Processing commands with Python
Sending messages with Python
Working with the network loop with Python
Test your knowledge
Summary
4. Interacting with Sensors in Java
Understanding the requirements
Defining the topics and commands
Installing the Eclipse Paho Java Client
Creating a security helper class to establish a TLS secured connection
Configuring a TLS secured connection in Java
Working with asynchronous notifications and callbacks in Java
Subscribing to topics and understanding notification events in Java
Processing commands that interact with sensors in Java
Working with last will and testament in Java
Publishing messages with commands to target sensors
Test your knowledge
Summary
5. Controlling Home Automation in JavaScript
Understanding the requirements
Defining the topics and commands to control home automation
Enabling WebSockets for a Mosquitto server
Testing WebSockets with the Eclipse Paho client JavaScript utility
Understanding the Eclipse Paho JavaScript asynchronous client
Creating an HTML 5 web page to control LEDs
Publishing messages to target remote devices in JavaScript
Processing the received messages in JavaScript
Working with WebSockets to connect to the MQTT server
Subscribing to topics in JavaScript
Processing commands that interact with LEDs in Node.js
Running the home automation web application
Debugging asynchronous code with Chrome Developer Tools (CDT) in JavaScript
Securing MQTT over WebSockets with TLS
Test your knowledge
Summary
6. Interacting with Actuators in Swift
Understanding the requirements
Defining topics and commands
Enabling connections without TLS for a Mosquitto server
Installing the CocoaMQTT client library to create a new iOS app
Building the UI for the iOS app that will control an actuator
Understanding the CocoaMQTT client in Swift 3
Connecting to the MQTT server and subscribing to topics in Swift
Publishing messages to target actuators in Swift
Processing commands that interact with actuators in Node.js
Running the iOS app that controls an actuator with MQTT
Debugging events in Swift
Test your knowledge
Summary
A. Exersise Answers
Chapter 1, Lightweight Messaging with MQTT 3.1.1 and Mosquitto
Chapter 2, Securing an MQTT Mosquitto Server
Chapter 3, Controlling a Drone with Python
Chapter 4, Interacting with Sensors in Java
Chapter 5, Controlling Home Automation in JavaScript
Chapter 6, Interacting with Actuators in Swift
MQTT Essentials - A Lightweight IoT Protocol
MQTT Essentials - A Lightweight IoT Protocol
Copyright © 2017 Packt Publishing
All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in
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Every effort has been made in the preparation of this book to ensure the accuracy of the information
presented. However, the information contained in this book is sold without warranty, either express or
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guarantee the accuracy of this information.
First published: April 2017
Production reference: 1050417
Published by Packt Publishing Ltd.
Livery Place
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ISBN 978-1-78728-781-5
www.packtpub.com
Credits
Author Copy Editor
Gastón C. Hillar Muktikant Garimella
Reviewer Project Coordinator
Ben Howes Ulhas Kambali
Commissioning Editor Proofreader
Smeet Thakkar Safis Editing
Acquisition Editor Indexer
Reshma Raman Aishwarya Gangawane
Content Development Editor Graphics
Vikas Tiwari Abhinash Sahu
Technical Editor Production Coordinator
Jijo Maliyekal Arvindkumar Gupta
About the Author
Gastón C. Hillar is Italian and has been working with computers since he was eight. He began
programming with the legendary Texas TI-99/4A and Commodore 64 home computers in the early 80s. He
has a bachelor's degree in computer science (graduated with honors), and an MBA (graduated with an
outstanding thesis). At present, Gastón is an independent IT consultant and freelance author who is always
looking for new adventures around the world.
He has been a senior contributing editor at Dr. Dobb’s and has written more than a hundred articles on
software development topics. Gastón was also a former Microsoft MVP in technical computing. He has
received the prestigious Intel® Black Belt Software Developer award eight times.
He is a guest blogger at Intel® Software Network (http://software.intel.com). You can reach him at
[email protected] and follow him on Twitter at http://twitter.com/gastonhillar. Gastón’s blog
is http://csharpmulticore.blogspot.com.
He lives with his wife, Vanesa, and his two sons, Kevin and Brandon.
Acknowledgment
At the time of writing this book, I was fortunate to work with an excellent team at Packt Publishing, whose
contributions vastly improved the presentation of this book. Reshma Raman allowed me to provide her
ideas for a book dedicated to MQTT, and I jumped into the exciting project of teaching the features of one
of the most important protocols for IoT projects with examples in many different programming languages.
Vikas Tiwari helped me realize my vision for this book and provided many sensible suggestions regarding
the text, the format, and the flow. The reader will notice his great work. It’s been great working with
Reshma and Vikas in another project and I can’t wait to work with them again. I would like to thank my
technical reviewers and proofreaders for their thorough reviews and insightful comments. I was able to
incorporate some of the knowledge and wisdom they have gained in their many years in the software
development industry. This book was possible because they gave valuable feedback.
The entire process of writing a book requires a huge number of lonely hours. I wouldn’t be able to write
an entire book without dedicating some time to play soccer against my sons, Kevin and Brandon, and my
nephew, Nicolas. Of course, I never won a match. However, I did score a few goals.
