fastapi-login 1.0.4

No project description provided

FastAPI-Login

FastAPI-Login tries to provide similar functionality as Flask-Login does.

Installation

$ pip install fastapi-login

Usage

To begin we have to setup our FastAPI app:

from fastapi import FastAPI

app = FastAPI()
app.config = {'secret': 'super-secret'}

The config should be a Mapping or implement the __getitem__ method.

Now we can import and setup the LoginManager, which will handle the process of encoding and decoding our Json Web Tokens.

from fastapi_login import LoginManager
manager = LoginManager(app)

For the example we will use a dictionary to represent our user database. In your application this could also be a real database like sqlite or Postgres. It does not matter as you have to provide the function which retrieves the user.

fake_db = {'[e-mail]': {'password': 'hunter2'}}

Now we have to provide the LoginManager with a way to load our user. The user_loader callback should either return your user object or None

@manager.user_loader
def load_user(email: str):  # could also be an asynchronous function
    user = fake_db.get(email)
    return user

Now we have to define a way to let the user login in our app. Therefore we will create a new route:

from fastapi import Depends
from fastapi.security import OAuth2PasswordRequestForm
from fastapi_login.exceptions import InvalidCredentialsException

@app.post('/auth/token')
def login(data: OAuth2PasswordRequestForm = Depends()):
    email = data.username
    password = data.password

    user = load_user(email)  # we are using the same function to retrieve the user
    if not user:
        raise InvalidCredentialsException  # you can also use your own HTTPException
    elif password != user['password']:
        raise InvalidCredentialsException

    access_token = manager.create_access_token(
        data=dict(sub=email)
    )
    return {'access_token': access_token, 'token_type': 'bearer'}

Now whenever you want your user to be logged in to use a route, you can simply use your LoginManager instance as a dependency.

from fastapi.security import OAuth2PasswordBearer
# this has to be set first in order to use the instance as dependency
manager.tokenUrl = '/auth/token'


@app.get('/protected')
def protected_route(user: Depends(manager)):
    ...