Book Image

The Definitive Guide to Modernizing Applications on Google Cloud

By : Steve (Satish) Sangapu, Dheeraj Panyam, Jason Marston
Book Image

The Definitive Guide to Modernizing Applications on Google Cloud

By: Steve (Satish) Sangapu, Dheeraj Panyam, Jason Marston

Overview of this book

Legacy applications, which comprise 75–80% of all enterprise applications, often end up being stuck in data centers. Modernizing these applications to make them cloud-native enables them to scale in a cloud environment without taking months or years to start seeing the benefits. This book will help software developers and solutions architects to modernize their applications on Google Cloud and transform them into cloud-native applications. This book helps you to build on your existing knowledge of enterprise application development and takes you on a journey through the six Rs: rehosting, replatforming, rearchitecting, repurchasing, retiring, and retaining. You'll learn how to modernize a legacy enterprise application on Google Cloud and build on existing assets and skills effectively. Taking an iterative and incremental approach to modernization, the book introduces the main services in Google Cloud in an easy-to-understand way that can be applied immediately to an application. By the end of this Google Cloud book, you'll have learned how to modernize a legacy enterprise application by exploring various interim architectures and tooling to develop a cloud-native microservices-based application.
Table of Contents (26 chapters)
1
Section 1: Cloud-Native Application Development and App Modernization in Google Cloud
5
Section 2: Selecting the Right Google Cloud Services
10
Section 3: Rehosting and Replatforming the Application
17
Section 4: Refactoring the Application on Cloud-Native/PaaS and Serverless in Google Cloud

Summary

In this chapter, we examined the packaging structure of our application and analyzed the services and dependencies in our banking-legacy-rest and banking-domain projects. We realized that UserService was not following the single responsibility principle and had two distinct responsibilities: user profiles and authentication. Based on this, we refactored the authentication responsibilities of UserService in AuthService, placing AuthService into its own project, along with TokenAuthenticationFilter. As both UserService and AuthService depend on User and UserRepository, we also placed User and UserRepository into their own project called user-core-domain. This allowed us to separate our concerns into two microservices, user-rest and account-rest. We then learned how to use two separate databases in our microservices to enable us to have a separate database for each microservice, as well as a shared database for authentication. Finally, we learned how to define container images...