FastAPI Auth Starter Project

This is a template for FastAPI that comes with authentication preconfigured.

Technology used

• FastAPI
• PostgreSQL
• SQLAlchemy
• Alembic

Use the template

Clone the repository

git clone https://github.com/sheyzi/fastapi_auth.git

Rename the project

mv fastapi_auth my_new_project

Change project name in core/settings.py

...

class Settings(BaseModel):
    PROJECT_TITLE: str = 'New Project name' # Updated
    PROJECT_VERSION: str = '1.0.0'

...

Create and activate virtual environment

python -m venv venv
source venv/bin/activate

Install dependencies

pip install -r requirements.txt

Rename sample.env to .env

mv sample.env .env

Get Deta project key

• Open Deta.sh
• Create an account or login
• In your dashboard click the back arrow beside the deta logo at the top left
• Click on the new project button
• Name your project and select a region
• Copy your project id and project key
• Replace the one in the .env file with the one you had just created

Change secret key

$ python
Python 3.8.10 (default, Nov 26 2021, 20:14:08)
[GCC 9.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import secrets
>>> secrets.token_hex()
'54e07b3ccd9f38e8601bd01d22537762dcff2c77957b2413ecf97e07e89e815e'
>>>

Replace the secret key in the .env file with the generated one

Configure database

Change the postgres sql information with their respective details in the .env file

Migrate the database

alembic upgrade head

Delete the current git repository

rm -rf .git

Run the project

python -m uvicorn main:app --reload

Open api docs

Navigate to 127.0.0.1:8000/docs

Add field to user model

The template comes without a username field, I will show you how to add that now!

• Edit the models/users.py to add the username field

...

class User(Base):
    __tablename__ = "users"

    id = Column(Integer, primary_key=True, index=True)
    email = Column(String, nullable=False, unique=True, index=True)
    username = Column(String, nullable=False) # New

...

• Reflect db changes on the pydantic schema in the schemas/users.py

...

class UserBase(BaseModel):
    email: str
    username: str #New

...

• Migrate the database

$ alembic revision --autogenerate -m "Added username field to users"
$ alembic upgrade head

Steps to add field to the users db

• Edit the models/users.py file
• Reflect changes in schemas/users.py file
• Migrate database

How to use the authentication

• Import the get_active_users dependency from the core/dependency.py

from core.dependency import get_active_user

• Import the Depends function from fastapi

from fastapi import Depends

• Import the UserOut class from the schemas/users.py

from schemas.users import UserOut

• Add the dependency to the route function

...

@auth_router.post("/some-route/")
def register_user(current_user: UserOut = Depends(get_active_user)):

...

How to create custom auth permissions

In this section we will create a permission for only admins

In core/dependency.py add

...

def get_admin_user(current_user: UserOut = Depends(get_active_user)):
    if not current_user.is_admin:
        raise HTTPException("Not an admin user!")
    return current_user

...