Book Image

Building Enterprise JavaScript Applications

By : Daniel Li
Book Image

Building Enterprise JavaScript Applications

By: Daniel Li

Overview of this book

With the over-abundance of tools in the JavaScript ecosystem, it's easy to feel lost. Build tools, package managers, loaders, bundlers, linters, compilers, transpilers, typecheckers - how do you make sense of it all? In this book, we will build a simple API and React application from scratch. We begin by setting up our development environment using Git, yarn, Babel, and ESLint. Then, we will use Express, Elasticsearch and JSON Web Tokens (JWTs) to build a stateless API service. For the front-end, we will use React, Redux, and Webpack. A central theme in the book is maintaining code quality. As such, we will enforce a Test-Driven Development (TDD) process using Selenium, Cucumber, Mocha, Sinon, and Istanbul. As we progress through the book, the focus will shift towards automation and infrastructure. You will learn to work with Continuous Integration (CI) servers like Jenkins, deploying services inside Docker containers, and run them on Kubernetes. By following this book, you would gain the skills needed to build robust, production-ready applications.
Table of Contents (26 chapters)
Title Page
Copyright and Credits
Packt Upsell
Free Chapter
The Importance of Good Code

Chapter 18. Robust Infrastructure with Kubernetes

In the previous chapter, we used Docker to pre-build and package different parts of our application, such as Elasticsearch and our API server, into Docker images. These images are portable and can be deployed independently onto any environment. Although this revised approach automated some aspects of our workflow, we are still manually deploying our containers on a single server.

This lack of automation presents the risk of human error. Deploying on a single server introduces a single point of failure (SPOF), which reduces the reliability of our application.

Instead, we should provide redundancy by spawning multiple instances of each service, and deploying them across different physical servers and data centers. In other words, we should deploy our application on a cluster.

Clusters allow us to have high availability, reliability, and scalability. When an instance of a service becomes unavailable, a failover mechanism can redirect unfulfilled...