FastAPI

A cookiecutter template for bootstrapping a FastAPI project using a modern stack.

Features

FastAPI (Python 3.8)
- JWT authentication using OAuth2 "password flow" and PyJWT
- Utility functions and higher-order components for handling authentication
PostgreSQL for the database
SqlAlchemy for ORM
Celery for background tasks and Redis as a message broker
- Includes Flower for task monitoring
Alembic for database migrations
Pytest for backend tests
- Includes test database, transaction rollbacks after each test, and reusable Pytest fixtures.
Prettier/ESLint (Airbnb style guide)
Docker Compose for development
Nginx as a reverse proxy to allow backend/frontend on the same port
- Using the same token based authentication as FastAPI backend (JWT)

Background
Quick Start
Develop
Admin Dashboard
Security
Testing
- Fixtures
Background Tasks
- Flower
Deployment
Contributing

Background

It is often laborsome to start a new project. 90% of the time you have to decide how to handle authentication, reverse proxies, docker containers, testing, server-side validation, linting, etc. before you can even get started.

Quick Start

First, install cookiecutter if you don't already have it:

pip3 install cookiecutter

Second, install docker-compose if you don't already have it:

docker-compose installation official docs.

Then, in the directory you want your project to live:

cookiecutter <path_to_the_fastapi_boilerplate_repo>

You will need to put in a few variables and it will create a project directory (called whatever you set for project_slug).

Input Variables

port [default 8000]
postgres_user [default postgres]
postgres_password [default password]
postgres_database [default app]
superuser_password [default password]
secret_key [default super_secret]

Develop

Change into your project directory and run:

chmod +x scripts/build.sh
./scripts/build.sh

This will build and run the docker containers, run the alembic migrations, and load the initial data (a test user).

It may take a while to build the first time it's run since it needs to fetch all the docker images.

Once you've built the images once, you can simply use regular docker-compose commands to manage your development environment, for example to start your containers:

docker-compose up -d

Note: If you see an Nginx error at first with a 502: Bad Gateway page, you may have to wait for webpack to build the development server (the nginx container builds much more quickly).

The backend docs will be at http://localhost:8000/api/docs.

Admin Dashboard

After starting the project, navigate to http://localhost:8000/admin. You should see a login screen. Use the username/password you set for the superuser on project setup.

NOTE: regular users will not be able to access the admin dashboard

Security

To generate a secure key used for encrypting/decrypting the JSON Web Tokens, you can run this command:

openssl rand -hex 32

The default is fine for development but you will want something more secure for production.

You can either set this on project setup as secret_key or manually edit the Python SECRET_KEY variable in backend/app/core/security.py.

Testing

This project comes with Pytest and a few Pytest fixtures for easier mocking. The fixtures are all located in backend/conftest.py within your project directory.

All tests are configured to run on a test database using SQLAlchemy transactions to reset the testing state on each function. This is to avoid a database call affecting the state of a different test.

Fixtures

These fixtures are included in backend/conftest.py and are automatically imported into any test files that being with test_.

test_db

The test_db fixture is an empty test database and an instance of a SQLAlchemy Session class.

def test_user(test_db):
    assert test_db.query(models.User).all()

test_user

def test_user_exists(test_user):
    assert test_user.email == "admin@example.com"

test_superuser

def test_superuser(client, test_superuser):
    assert test_superuser.is_superuser

client

To use an unauthenticated test client, use client:

def test_get_users(client):
    client.get("/api/v1/users")
    assert response.status_code == 200

user_token_headers

If you need an authenticated client using OAuth2 and JWTs:

def test_user_me(client, user_token_headers):
    response = client.get(
      "/api/v1/users/me",
      headers=user_token_headers,
    )
    assert response.status_code == 200

Since OAuth2 expects the access token in the headers, you will need to pass in user_token_headers as the headers argument in any client request that requires authentication.

superuser_token_headers

def test_user_me(client, superuser_token_headers):
    response = client.get(
      "/api/v1/users",
      headers=superuser_token_headers,
    )
    assert response.status_code == 200

Background Tasks

This template comes with Celery and Redis Docker containers pre-configured for you. For any long running processes, it's recommended that you handle these using a task queue like Celery to avoid making the client wait for a request to finish. Some examples of this might be sending emails, uploading large files, or any long running, resource intensive tasks.

There is an example task in backend/app/tasks.py and an example Celery test in backend/app/tests/test_tasks.py. This test runs synchronously, which is what Celery docs recommend.

If you are not happy with Celery or Redis, it should be easy to swap these containers out with your favorite tools. Some suggested alternatives might be Huey as the task queue and RabbitMQ for the message broker.

Flower

You can monitor tasks using Flower by going to http://localhost:5555

Frontend Utilities

There are a few helper methods to handle authentication in frontend/src/utils. These store and access the JWT returned by FastAPI in local storage. Even though this doesn't add any security, we prevent loading routes that might be protected on the frontend, which results in a better UX experience.

Utility Functions

login

// in src/utils/auth.ts

/**
 *  Handles authentication with backend and stores in JWT in local storage
 **/
const login = (email: string, password: string) => boolean;

logout

// in src/utils/auth.ts

// clears token from local storage
const logout = (email: string, password: string) => void;

isAuthenticated

// Checks authenticated state from JWT tokens
const isAuthenticated = () => boolean;

Routes

Some basic routes are included (and handled in frontend/Routes.tsx).

/login - Login screen
/logout - Logout
/ - Home
/protected - Example of protected route

Higher Order Components

PrivateRoute

Deployment

This stack can be adjusted and used with several deployment options that are compatible with Docker Compose, but it may be easiest to use Docker in Swarm Mode with an Nginx main load balancer proxy handling automatic HTTPS certificates, using the ideas from DockerSwarm.rocks.

Please refer to DockerSwarm.rocks to see how to deploy such a cluster easily. You will have to change the Traefik examples to Nginx or update your docker-compose file.

Contributing

Contributing is more than welcome. Please read the Contributing doc to find out more.

almeidacavalcante/fastapi-boilerplate