Book Image

Building Python Microservices with FastAPI

By : Sherwin John C. Tragura
3 (2)
Book Image

Building Python Microservices with FastAPI

3 (2)
By: Sherwin John C. Tragura

Overview of this book

FastAPI is an Asynchronous Server Gateway Interface (ASGI)-based framework that can help build modern, manageable, and fast microservices. Because of its asynchronous core platform, this ASGI-based framework provides the best option when it comes to performance, reliability, and scalability over the WSGI-based Django and Flask. When working with Python, Flask, and Django microservices, you’ll be able to put your knowledge to work with this practical guide to building seamlessly manageable and fast microservices. You’ll begin by understanding the background of FastAPI and learning how to install, configure, and use FastAPI to decompose business units. You’ll explore a unique and asynchronous REST API framework that can provide a better option when it comes to building microservices. After that, this book will guide you on how to apply and translate microservices design patterns in building various microservices applications and RESTful APIs using the FastAPI framework. By the end of this microservices book, you’ll be able to understand, build, deploy, test, and experiment with microservices and their components using the FastAPI framework.
Table of Contents (17 chapters)
1
Part 1: Application-Related Architectural Concepts for FastAPI microservice development
6
Part 2: Data-Centric and Communication-Focused Microservices Concerns and Issues
11
Part 3: Infrastructure-Related Issues, Numerical and Symbolic Computations, and Testing Microservices

Testing the API endpoints

FastAPI uses the pytest framework to run its test classes. So, before we create our test classes, first, we need to install the pytest framework using the pip command:

pip install pytest

FastAPI has a module called fastapi.testclient where all components are Request-based, including the TestClient class. To access all the API endpoints, we need the TestClient object. But first, we need to create a folder such as test, which will contain test modules where we implement our test methods. We place our test methods outside main.py or the router modules to maintain clean code and organization.

Writing the unit test cases

It is a best practice to write one test module per router component, except for cases where there is a tight connection between these routers. We place these test modules inside the test directory. To pursue the automated testing, we need to import the APIRouter instance or the FastAPI instance into the test module to set up TestClient...