Book Image

Microservices with Clojure

By : Anuj Kumar
Book Image

Microservices with Clojure

By: Anuj Kumar

Overview of this book

The microservice architecture is sweeping the world as the de facto pattern with which to design and build scalable, easy-tomaintain web applications. This book will teach you common patterns and practices, and will show you how to apply these using the Clojure programming language. This book will teach you the fundamental concepts of architectural design and RESTful communication, and show you patterns that provide manageable code that is supportable in development and at scale in production. We will provide you with examples of how to put these concepts and patterns into practice with Clojure. This book will explain and illustrate, with practical examples, how teams of all sizes can start solving problems with microservices. You will learn the importance of writing code that is asynchronous and non-blocking and how Pedestal helps us do this. Later, the book explains how to build Reactive microservices in Clojure that adhere to the principles underlying the Reactive Manifesto. We finish off by showing you various ways to monitor, test, and secure your microservices. By the end, you will be fully capable of setting up, modifying, and deploying a microservice with Clojure and Pedestal.
Table of Contents (18 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
Index

Clojure and REPL


Clojure (https://clojure.org/) is a dialect of the Lisp (https://en.wikipedia.org/wiki/Lisp_(programming_language) programming language and primarily runs on a Java virtual machine (JVM). The other target implementations include ClojureCLR (https://github.com/clojure/clojure-clr), which runs on Common Language Runtime (CLR), and ClojureScript, which compiles to JavaScript. Although Clojure uses a JVM as its underlying runtime engine, it emphasizes a functional programming language with immutability at its core. All data structures of Clojure are immutable. Since Clojure is a dialect of Lisp, it also treats code as data and is known to be homoiconic. Its syntax is built on S-expressions (https://en.wikipedia.org/wiki/S-expression) that are first parsed as a data structure and then translated into constructs of the Java programming language before being compiled into Java bytecode. Clojure also supports metaprogramming with macro (https://en.wikipedia.org/wiki/Macro_(computer_science...