TypeScript Microservices

▶Book Description
In the last few years or so, microservices have achieved the rock star status and right now are one of the most tangible solutions in enterprises to make quick, effective, and scalable applications. The apparent rise of Typescript and long evolution from ES5 to ES6 has seen lots of big companies move to ES6 stack. If you want to learn how to leverage the power of microservices to build robust architecture using reactive programming and Typescript in Node.js, then this book is for you.

Typescript Microservices is an end-to-end guide that shows you the implementation of microservices from scratch; right from starting the project to hardening and securing your services. We will begin with a brief introduction to microservices before learning to break your monolith applications into microservices. From here, you will learn reactive programming patterns and how to build APIs for microservices. The next set of topics will take you through the microservice architecture with TypeScript and communication between services. Further, you will learn to test and deploy your TypeScript microservices using the latest tools and implement continuous integration. Finally, you will learn to secure and harden your microservice.

By the end of the book, you will be able to build production-ready, scalable, and maintainable microservices using Node.js and Typescript.

▶What You Will Learn
⦁ Get acquainted with the fundamentals behind microservices.
⦁ Explore the behavioral changes needed for moving from monolithic to microservices.
⦁ Dive into reactive programming, Typescript and Node.js to learn its fundamentals in microservices
⦁ Understand and design a service gateway and service registry for your microservices.
⦁ Maintain the state of microservice and handle dependencies.
⦁ Perfect your microservice with unit testing and Integration testing
⦁ Develop a microservice, secure it, deploy it, and then scale it

▶Key Features
⦁ Learn to build message-driven services for effective communication
⦁ Design microservices API using Reactive programming design patterns
⦁ Deploy, scale and monitor microservices for consistent high performance

▶Who This Book Is For
This book is for JavaScript developers seeking to utilize their Node.js and TypeScript skills to build microservices and move away from the monolithic style of architecture. Prior knowledge of TypeScript and Node.js is assumed. This book will help answer some of the important questions concerning what problems a microservice solves and how an organization has to be structured to adopt microservices.

▶What this book covers
⦁ Chapter 1, Debunking Microservices, gives you an introduction to the world of microservices. It begins with the transition from monolithic to microservice architectures. This chapter gets you acquainted with the evolution of the microservices world; answers to frequently asked questions that come up about microservices, and familiarizes you with various microservice design aspects, twelve-factor applications for microservices; and various design patterns for microservice implementations along with their pros, cons, and when to and when not to use them.

⦁ Chapter 2, Gearing up for the Journey, introduces necessary concepts in Node.js and TypeScript. It begins with preparing our development environment. It then talks about basic TypeScript essentials such as types, tsconfig.json, writing your custom types for any node module, and the Definitely Typed repository. Then, we move to Node.js, where we write our application in TypeScript. We will learn about some essentials such as Node clusters, Event Loops, multithreading, and async/await. Then, we move to writing our first hello world TypeScript microservice.

⦁ Chapter 3, Exploring Reactive Programming, gets into the world of reactive programming. It explores the concepts of reactive programming along with its approaches and advantages. It explains how reactive programming is different from traditional approaches and then moves to practical examples with Highland.js, Bacon.js, and RxJS. It concludes by comparing all the three libraries along with their pros and cons.

⦁ Chapter 4, Beginning Your Microservices Journey, begins our microservices case study—.the shopping cart microservices. It begins with the functional requirements of the system, followed by overall business capabilities. We start the chapter with architectural aspects, design aspects, and overall components in the ecosystem, before moving to the data layers of microservices, wherein we will have an in-depth discussion on the types of data and how the database layer should be. Then, we develop microservices with the approach of separation of concerns and learn about some microservices best practices.

⦁ Chapter 5, Understanding API Gateway, explores the designs involved in an API Gateway. It tells why an API Gateway is required and what its functions are. We will explore various API Gateway designs and the various options available in them. We will look at the circuit breaker and why it plays an important role as part of a client resiliency pattern.

⦁ Chapter 6, Service Registry and Discovery, talks about introducing a service registry in your microservices ecosystem. The number of services and/or location of services can remain in flux based on load and traffic. Having a static location disturbs the principles of microservices. This chapter deals with the solution and talks about service discovery and registry patterns in depth. The chapter further explains various options available and discusses Consul and Eureka in detail.

⦁ Chapter 7, Service State and Interservice Communication, focuses on interservice communication. Microservices need to collaborate with each other in order to achieve a business capability. The chapter explores various modes of communication. It then talks about next-gen communication styles including RPC and the HTTP 2.0 protocol. We learn about service state and at where the state can be persisted. We go through various kinds of database system along with their use cases. The chapter explores the world of caching, sharing code among dependencies, and versioning strategies, and details how to get client resiliency patterns to handle failures.

⦁ Chapter 8, Testing, Debugging, and Documenting, outlines life after development. We learn how to write test cases and plunge into the world of BDD and TDD through some famous toolsets. We see contract testing for microservices—.a way to ensure that there are no groundbreaking changes. We then see debugging and how to profile our service and all the options available to us. We move on to documenting and understanding the needs of documentation and all the toolsets involved around Swagger, the tool that we will use.

⦁ Chapter 9, Deployment, Logging, and Monitoring, covers deployment and various options involved in it. We see a build pipeline, and we get acquainted with continuous integration and continuous delivery. We understand Docker in detail and dockerize our application by adding Nginx in front of our microservice. We move on to logging and understand the need for a customized, centralized logging solution. We finally move on to monitoring and understanding the various options available, such as keymetrics, Prometheus, and Grafana.

⦁ Chapter 10, Hardening Your Application, looks at hardening the application, addressing security and scalability. It talks about security best practices that should be in place to avoids any mishaps. It gives a detailed security checklist that can be used at the time of deployment. We will then learn about scalability with AWS and Kubernetes. We will see how to solve scaling problems with AWS by automatically adding or removing an EC2 instance. The chapter concludes with Kubernetes and its example.