Book Image

Python Microservices Development

Book Image

Python Microservices Development

Overview of this book

We often deploy our web applications into the cloud, and our code needs to interact with many third-party services. An efficient way to build applications to do this is through microservices architecture. But, in practice, it's hard to get this right due to the complexity of all the pieces interacting with each other. This book will teach you how to overcome these issues and craft applications that are built as small standard units, using all the proven best practices and avoiding the usual traps. It's a practical book: you’ll build everything using Python 3 and its amazing tooling ecosystem. You will understand the principles of TDD and apply them. You will use Flask, Tox, and other tools to build your services using best practices. You will learn how to secure connections between services, and how to script Nginx using Lua to build web application firewall features such as rate limiting. You will also familiarize yourself with Docker’s role in microservices, and use Docker containers, CoreOS, and Amazon Web Services to deploy your services. This book will take you on a journey, ending with the creation of a complete Python application based on microservices. By the end of the book, you will be well versed with the fundamentals of building, designing, testing, and deploying your Python microservices.
Table of Contents (20 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Introduction

The asyncio library


The asyncio (https://docs.python.org/3/library/asyncio.html) library, which was originally an experiment called Tulip run by Guido, provides all the infrastructure to build asynchronous programs based on an event loop.

The library predates the introduction of async, await, and native coroutines in the language.

The asyncio library is inspired by Twisted, and offers classes that mimic Twisted transports and protocols. Building a network application based on these consists of combining a transport class (like TCP) and a protocol class (such as HTTP), and using callbacks to orchestrate the execution of the various parts.

But, with the introduction of native coroutines, callback-style programming is less appealing, since it's much more readable to orchestrate the execution order via await calls. You can use coroutine with asyncio protocol and transport classes, but the original design was not meant for that and requires a bit of extra work.

However, the central feature is the...