User Authentication with Flask-Login

🐍 FlaskLesson 9Intermediate

Flask-Login handles user sessions (logging in, logging out, and remembering users) in your Flask application. It works in tandem with Werkzeug password hashing utilities.

1 Authentication Integration

Python — auth.py

from flask_login import LoginManager, UserMixin, login_user, logout_user, login_required
from werkzeug.security import generate_password_hash, check_password_hash

login_manager = LoginManager()

class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True)
    password_hash = db.Column(db.String(128))

    def set_password(self, password):
        self.password_hash = generate_password_hash(password)

    def check_password(self, password):
        return check_password_hash(self.password_hash, password)

@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))

2 Code Challenge

Challenge: Create a protected route /admin-only that validates that the authenticated user's username is "admin" before granting access, otherwise returning a 403 Forbidden page.