To better understand and follow the recipes in this book, it will help if you have some basic knowledge of blockchain technology and cryptograph concepts, have a basic understanding of programming languages for JavaScript, Go, and Python, some basic Unix skills, in particular, shell command, and are familiar with basic flows for launching and running applications in the cloud, such as Amazon AWS.

You can download the example code files for this book from your account at www.packt.com. If you purchased this book elsewhere, you can visit www.packt.com/support and register to have the files emailed directly to you.

You can download the code files by following these steps:

1. Log in or register at www.packt.com.
2. Select the SUPPORT tab.
3. Click on Code Downloads & Errata.
4. Enter the name of the book in the Search box and follow the onscreen instructions.

Once the file is downloaded, please make sure that you unzip or extract the folder using the latest version of:

• WinRAR/7-Zip for Windows
• Zipeg/iZip/UnRarX for Mac
• 7-Zip/PeaZip for Linux

The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/Hyperledger-Cookbook. In case there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "Install Node.js, npm, and Python."

A block of code is set as follows:

type Chaincode interface {
    Init (stub ChaincodeStubInterface) pb.Response
    Invoke (stub ChaincodeStubInterface) pb.Response
}

Any command-line input or output is written as follows:

  $ sudo apt-get update

Bold: Indicates a new term, an important word, or words that you see on screen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Click on the Query Chaincode button."