Book Image

Building Microservices with Micronaut®

By : Nirmal Singh, Zack Dawood
Book Image

Building Microservices with Micronaut®

By: Nirmal Singh, Zack Dawood

Overview of this book

The open source Micronaut® framework is a JVM-based toolkit designed to create microservices quickly and easily. This book will help full-stack and Java developers build modular, high-performing, and reactive microservice-based apps using the Micronaut framework. You'll start by building microservices and learning about the core components, such as ahead-of-time compilation, reflection-less dependency injection, and reactive baked-in HTTP clients and servers. Next, you will work on a real-time microservice application and learn how to integrate Micronaut projects with different kinds of relational and non-relational databases. You'll also learn how to employ different security mechanisms to safeguard your microservices and integrate microservices using event-driven architecture in the Apache Kafka ecosystem. As you advance, you'll get to grips with automated testing and popular testing tools. The book will help you understand how you can easily handle microservice concerns in Micronaut projects, such as service discovery, API documentation, distributed configuration management, fallbacks, and circuit breakers. Finally, you'll explore the deployment and maintenance aspects of microservices and get up to speed with the Internet of Things (IoT) using the Framework. By the end of this book, you'll be able to build, test, deploy, and maintain your own microservice apps using the framework.
Table of Contents (20 chapters)
1
Section 1: Core Concepts and Basics
3
Section 2: Microservices Development
8
Section 3: Microservices Testing
10
Section 4: Microservices Deployment
13
Section 5: Microservices Maintenance
15
Section 6: IoT with Micronaut and Closure

Implementing the API gateway

To further the earlier discussion on dynamic network locations in the microservices architecture, we will focus on the API gateway now. The API gateway is an orchestrator service meant to provide unified, ubiquitous access to all the services. Though we can have multiple microservices running in the backend, an API gateway can provide a unified interface for the upstream consumers to access them. For the upstream consumers, the API gateway appears to be the only service running in the backend. On receiving a client request, the API gateway determines which service instance to call using service discovery.

In order to learn how to implement the API gateway, we will add an API gateway service to the pet-clinic application. Since this microservice is an orchestrator service, we can call it pet-clinic-concierge. The system components after the gateway service would be as seen in Figure 7.6:

Figure 7.6 – Pet Clinic Application...