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

Running Flask in Docker


To run a Flask application in Docker, we can use the base Python image.

From there, installing the app and its dependencies can be done via PIP, which is already installed in the Python image.

Assuming your project has a requirements.txt file for its pinned dependencies, and a setup.py file that installs the project, creating an image for your project can be done by instructing Docker how to use the pip command.

In the following example, we add two new instructions--the COPY command recursively copies a directory structure inside the Docker image, and the ;RUN ;command runs PIP via shell commands:

FROM python:3.6 
COPY . /app 
RUN pip install -r /app/requirements.txt 
RUN pip install /app/ 

EXPOSE 5000 
CMD runnerly-tokendealer

The 3.6 tag here will get the latest Python 3.6 image that was uploaded to the Hub.

The COPY command automatically creates the top-level app directory in the container, and copies everything from "." in it. One important detail to remember with...