Book Image

Blockchain with Hyperledger Fabric - Second Edition

By : Nitin Gaur, Anthony O'Dowd, Petr Novotny, Luc Desrosiers, Venkatraman Ramakrishna, Salman A. Baset
Book Image

Blockchain with Hyperledger Fabric - Second Edition

By: Nitin Gaur, Anthony O'Dowd, Petr Novotny, Luc Desrosiers, Venkatraman Ramakrishna, Salman A. Baset

Overview of this book

Blockchain with Hyperledger Fabric - Second Edition is a refreshed and extended version of the successful book on practical Hyperledger Fabric blockchain development. This edition includes many new chapters, alongside comprehensive updates and additions to the existing ones. Entirely reworked for Hyperledger Fabric version 2, this edition will bring you right up to date with the latest in blockchain. Using a real-world Trade Finance and Logistics example, with working code available on GitHub, you’ll really understand both how and why Hyperledger Fabric can be used to maximum effect. This book is your comprehensive guide and reference to explore and build blockchain networks using Hyperledger Fabric version 2. This edition of the book begins by outlining the evolution of blockchain, including an overview of relevant blockchain technologies. Starting from first principles, you’ll learn how to design and operate a permissioned blockchain network based on Hyperledger Fabric version 2. You will learn how to configure the main architectural components of a permissioned blockchain network including Peers, Orderers, Certificate Authorities, Channels, and Policies. You’ll then learn how to design, develop, package, and deploy smart contracts, and how they are subsequently used by applications. This edition also contains chapters on DevOps, blockchain governance, and security, making this your go-to book for Hyperledger Fabric version 2.
Table of Contents (18 chapters)
16
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17
Index

Querying the ledger

The simplest operation an application can perform is to query a ledger. Let's examine how the registration and trading applications query a ledger in different networks:

Figure 7.10: The simplest operation an application can perform is to query a ledger

In Figure 7.10, we can see that peer1 has the registration contract installed, making it available to all applications connected to the vehicle-registration network. Similarly, Peer1 also has car contract installed for participants in the car-trading network. The registration application uses the registration contract to query the registration ledger, and the car contract to query the trading ledger.

But where are the registration and car ledgers in Figure 7.10? Let's take a closer look at the smart contracts to find out.

Smart contract packaging and namespaces

Smart contracts are placed in a package for both logical grouping and distribution. Consider an example:

Figure...