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
Dedication
Packt Upsell
Contributors
Preface
Free Chapter
1
The Importance of Good Code
Index

Declarative over imperative


Pods, Deployments, and ReplicaSet are examples of Kubernetes Objects. Kubernetes provides you with multiple approaches to run and manage them.

  • kubectl run—imperative: You provide instructions through the command line to the Kubernetes API to carry out
  • kubectl create—imperative: You provide instructions, in the form of a configuration file, to the Kubernetes API to carry out
  • kubectl apply—declarative: You tell the Kubernetes API the desired state of your cluster using configuration file(s), and Kubernetes will figure out the operations required to reach that state

kubectl create is a slight improvement to kubectl run because the configuration file(s) can now be version controlled; however, it is still not ideal due to its imperative nature.

If we use the imperative approach, we'd be manipulating the Kubernetes object(s) directly, and thus be responsible for monitoring all Kubernetes objects. This essentially defeats the point of having a Cluster Management Tool.

The...