derevenetsartyom / tdd-fastapi

Text summarization service with Python, FastAPI, and Docker. The service itself is exposed via a RESTful API and deployed to Heroku with Docker.

Test-Driven Development with FastAPI and Docker

• https://secret-dusk-86918.herokuapp.com/docs
• https://secret-dusk-86918.herokuapp.com/summaries/
• https://secret-dusk-86918.herokuapp.com/summaries/4/

Table of contents

• About
  • Objectives achieved in the project
  • Tools and technologies
  • Endpoints
• Useful commands

About

fastapi-tdd is a code-along (with some differences) to the course Test-Driven Development with FastAPI and Docker by Michael Herman. Link to original repo.

Objectives achieved in the project

• Develop an asynchronous RESTful API with Python and FastAPI
• Practice Test-Driven Development
• Test a FastAPI app with pytest
• Interact with a Postgres database asynchronously
• Containerize FastAPI and Postgres inside a Docker container
• Run unit and integration tests with code coverage inside a Docker container
• Check the code for any code quality issues via a linter
• Configure GitHub Actions for continuous integration and deployment
• Use GitHub Packages to store Docker Images
• Speed up a Docker-based CI build with Docker Cache
• Deploy FastAPI, Uvicorn, and Postgres to Heroku with Docker
• Parameterize test functions and mock functionality in tests with pytest
• Run tests in parallel with pytest-xdist
• Document a RESTful API with Swagger/OpenAPI (out of the box)
• Run a background process outside the request/response flow

Tools and technologies

This project uses a variety of technologies and services:

• Core

  • Python
  • FastAPI
  • Docker
  • Docker Compose
  • Postgres
  • Tortoise ORM
  • Aerich
  • Uvicorn
  • Gunicorn
  • Swagger/OpenAPI

• Testing and Linting

  • Pytest
  • Coverage.py
  • Flake8
  • Black
  • isort
  • HTTPie

• Services

  • GitHub Actions
  • GitHub Packages
  • Heroku

Endpoints

Endpoint	HTTP Method	CRUD Method	Result
/summaries	GET	READ	get all summaries
/summaries/:id	GET	READ	get a single summary
/summaries	POST	CREATE	add a summary
/summaries/:id	PUT	UPDATE	update a summary
/summaries/:id	DELETE	DELETE	delete a summary
/ping	GET	------	get test json
/docs	GET	------	get the docs

Useful commands

Build and Launch Containers

docker-compose up -d --build

Accessing Database

docker-compose exec web-db psql -U postgres

postgres=# \c web_dev
postgres=# \q

Update Database Schema

docker-compose exec web python app/db.py

Run Tests

# normal run
$ docker-compose exec web python -m pytest

# disable warnings
$ docker-compose exec web python -m pytest -p no:warnings

# run only the last failed tests
$ docker-compose exec web python -m pytest --lf

# run only the tests with names that match the string expression
$ docker-compose exec web python -m pytest -k "summary and not test_read_summary"

# stop the test session after the first failure
$ docker-compose exec web python -m pytest -x

# enter PDB after first failure then end the test session
$ docker-compose exec web python -m pytest -x --pdb

# stop the test run after two failures
$ docker-compose exec web python -m pytest --maxfail=2

# show local variables in tracebacks
$ docker-compose exec web python -m pytest -l

# list the 2 slowest tests
$ docker-compose exec web python -m pytest --durations=2

#Run unit tests in parallel
$ docker-compose exec web pytest -k "unit" -n auto

Build container for Heroku

docker build -f src/Dockerfile.prod -t registry.heroku.com/secret-dusk-86918/web ./src

Run Heroku container locally

docker run -d --name fastapi-tdd -e PORT=8765 -e DATABASE_URL=sqlite://sqlite.db -p 5003:8765 registry.heroku.com/secret-dusk-86918/web:latest

Push Container to Heroku Registry

docker push registry.heroku.com/secret-dusk-86918/web:latest

Build the image for GitHub

docker build -f src/Dockerfile.prod -t docker.pkg.github.com/derevenetsartyom/tdd-fastapi/summarizer:latest ./src/

Push the image to the Docker registry on GitHub Packages

docker push docker.pkg.github.com/derevenetsartyom/tdd-fastapi/summarizer:latest