Book Image

Event-Driven Architecture in Golang

By : Michael Stack
5 (1)
Book Image

Event-Driven Architecture in Golang

5 (1)
By: Michael Stack

Overview of this book

Event-driven architecture in Golang is an approach used to develop applications that shares state changes asynchronously, internally, and externally using messages. EDA applications are better suited at handling situations that need to scale up quickly and the chances of individual component failures are less likely to bring your system crashing down. This is why EDA is a great thing to learn and this book is designed to get you started with the help of step-by-step explanations of essential concepts, practical examples, and more. You’ll begin building event-driven microservices, including patterns to handle data consistency and resiliency. Not only will you learn the patterns behind event-driven microservices but also how to communicate using asynchronous messaging with event streams. You’ll then build an application made of several microservices that communicates using both choreographed and orchestrated messaging. By the end of this book, you’ll be able to build and deploy your own event-driven microservices using asynchronous communication.
Table of Contents (18 chapters)
Part 1: Event-Driven Fundamentals
Part 2: Components of Event-Driven Architecture
Part 3: Production Ready

Testing component interactions with contract tests

We have chosen to create our application using the modular monolith pattern. Here, we have each module communicate with the others using either gRPC or by publishing messages into a message broker. These would be very common to see on any distributed application but would be rare or not used at all on a monolith or small application. What’s more common to see across all applications is the REST API we use. This demonstration application does not have any true UI, but we have the API to support one. This API represents a third form of communication in our application, which is between an API provider and the API consumer.

We could test these interactions using integration tests since the definition of what an integration test covers is testing the interactions or integration between two components. However, the integration tests we wrote before tested smaller components, and the scope for the system under test was not very...