Book Image

Mastering Elixir

By : André Albuquerque, Daniel Caixinha
Book Image

Mastering Elixir

By: André Albuquerque, Daniel Caixinha

Overview of this book

Running concurrent, fault-tolerant applications that scale is a very demanding responsibility. After learning the abstractions that Elixir gives us, developers are able to build such applications with inconceivable low effort. There is a big gap between playing around with Elixir and running it in production, serving live requests. This book will help you fll this gap by going into detail on several aspects of how Elixir works and showing concrete examples of how to apply the concepts learned to a fully ?edged application. In this book, you will learn how to build a rock-solid application, beginning by using Mix to create a new project. Then you will learn how the use of Erlang's OTP, along with the Elixir abstractions that run on top of it (such as GenServer and GenStage), that allow you to build applications that are easy to parallelize and distribute. You will also master supervisors (and supervision trees), and comprehend how they are the basis for building fault-tolerant applications. Then you will use Phoenix to create a web interface for your application. Upon fnishing implementation, you will learn how to take your application to the cloud, using Kubernetes to automatically deploy, scale, and manage it. Last, but not least, you will keep your peace of mind by learning how to thoroughly test and then monitor your application.
Table of Contents (18 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
5
Demand-Driven Processing
Index

Authenticating users


In the last chapter, we saw how we handle user passwords in the Accounts context, using the comeonin library to sign and verify them. In this chapter, our focus is on extending our web interface to allow users to sign up and log in to our application, and also to restrict certain pages to logged in users. There's a myriad of libraries in the Elixir ecosystem that would allow us to achieve this in only a few lines of code. However, implementing our own authentication solution is beneficial for two reasons: it will give us the opportunity to explore Phoenix in greater depth and it will give us more freedom in how the authentication is made, allowing us to adapt it to fit our needs.

In order to have users authenticated, we first need to have the ability to create users in our application. We'll do this part from the bottom up, building the logic around the authentication of a user, and when that part is done, we'll work on allowing a user to sign up and log in.

As we hinted...