session.py - Session Management

The main thing in this file is to create the auth manager and to provide a user_loader The auth manager uses the user_loader on every route that requires authentication The way we do protected routes in FastAPI is to include a parameter on the endpoint user=Depends(auth_manager) This will cause the JWT token (provided in a cookie) OR in a header to be validated. If the token is valid then the user will be looked up in the database using the load_user function in this file. see auth.py - Validation and Authentication for more detail.

Imports

These are listed in the order prescribed by PEP 8.

Standard library

from typing import Awaitable, Callable, cast
 

Third-party imports

from fastapi import Request
from fastapi.exceptions import HTTPException
from fastapi_login import LoginManager
 

Local application imports

from .config import settings
from .crud import fetch_instructor_courses, fetch_user
from .applogger import rslogger
from .models import AuthUserValidator


auth_manager = LoginManager(settings.jwt_secret, "/auth/validate", use_cookie=True)
auth_manager.cookie_name = "access_token"


@auth_manager.user_loader()  # type: ignore
async def _load_user(user_id: str) -> AuthUserValidator:

fetch a user object from the database. This is designed to work with the original web2py auth_user schema but make it easier to migrate to a new database by simply returning a user object.

    rslogger.debug(f"Going to fetch {user_id}")
    return await fetch_user(user_id)

The user_loader decorator doesn’t propagate type hints. Fix this manually.

load_user = cast(Callable[[str], Awaitable[AuthUserValidator]], _load_user)


async def is_instructor(request: Request) -> bool:
    user = request.state.user
    if user is None:
        raise HTTPException(401)
    elif len(await fetch_instructor_courses(user.id, user.course_id)) > 0:
        return True
    else:
        return False