This project contains the version 9 of the application that is developed under the scope of the book Learn Microservices with Spring Boot. You can get a copy of the book on Amazon or Apress.
The book shows you how to evolve a simple Spring Boot application to become a full Microservices Architecture, using Spring Cloud Eureka, Ribbon, Zuul and Hystrix to implement Service Discovery, Load Balancing, the API Gateway pattern and a Circuit Breaker. Besides, you'll learn how to implement End-to-End tests with Cucumber, an Event-Driven system and the best practices when building Microservices.
These projects, included in Microservices-Practical repositories, illustrate how to start an application from scratch and then evolve it to become a full microservices environment.
This version introduces end to end testing with Cucumber JVM.
The repository contains six folders, one for each component of the system:
- social-multiplication is one of the backend services. It has a REST API to get and provide results to simple multiplications. When an attempt is sent, it triggers an event.
- gamification is the second backend service. It provides a REST API to get game stats and reacts to the event sent by the multiplication service, updating the figures.
- service-registry is the Eureka Server, which is contacted by backend services and the gateway.
- gateway is the Routing Service, implemented with Zuul. It connects with Eureka for service discovery, and performs load balancing with Ribbon.
- ui contains the static files of the frontend application. It's configured to be started with Jetty.
- tests_e2e contains the end to end test cases, developed with Cucumber (Gherkin notation)
These are the instructions:
- UI. Download and install Jetty. From the command line, execute
java -jar [JETTY_HOME]/jetty-[VERSION]/start.jar(replace the values between brackets accordingly). You also need Java. - RabbitMQ. Download and install RabbitMQ. We use it as Event bus. When you have installed it, you need to run the RabbitMQ server (as a service or as a process, whatever you prefer).
- Multiplication, Gamification, Service Registry and Gateway. You need to start all these services using the command line. Navigate to each folder and execute for every one of them:
./mvnw spring-boot:run. If you want to try load balancing you can execute more than one instance of the Multiplication or Gamification service. To do that, override the port number to avoid clashing:./mvnw spring-boot:run -Drun.arguments="--server.port=A_FREE_PORT]"
If you want more details about the different application parts and how to get there from scratch, you can buy the book on Apress or Amazon.