Secure User Access with Flask-Login: A Guide to Authentication and Authorization

[ad_1]

Creating User Authentication and Authorization with Flask-Login

As a web developer, one of the most common features you’ll need to add to your web app is user authentication. This means allowing users to sign up and log in to your app, as well as protecting certain pages so that only logged-in users can access them.

In this blog post, we’ll cover how to add simple authentication to your Flask app using the Flask-Login library. We’ll also use Flask-SQLAlchemy to create a user model and handle database interactions. By the end of this tutorial, you’ll have a basic understanding of how to implement user authentication in your Flask app.

Getting Started

Before we dive into the code, let’s go over the tools and packages we’ll be using for our project. You’ll need to have the following packages installed in your virtual environment:

– Flask
– Flask-Login
– Flask-SQLAlchemy

We’ll also be using SQLite for our database, so you won’t need to install any additional dependencies.

Creating the Project Structure

First, let’s create the directories and files for our project. We’ll be using the Flask app factory pattern with blueprints, so our project structure will look like this:

– project
|– templates
| |– base.html
| |– index.html
| |– login.html
| |– profile.html
| |– signup.html
|– __init__.py
|– auth.py
|– main.py
|– models.py

Feel free to create these files and we’ll add the code as we go along.

Creating the Flask App

In our __init__.py file, we’ll have the function to create our Flask app. This function will initialize the database and register our blueprints. It should look something like this:

__init__.py

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()

def create_app():
app = Flask(__name__)
app.config[‘SECRET_KEY’] = ‘9OLWxND4o83j4K4iuopO’
app.config[‘SQLALCHEMY_DATABASE_URI’] = ‘sqlite:///db.sqlite’

db.init_app(app)

from .auth import auth as auth_blueprint
app.register_blueprint(auth_blueprint)

from .main import main as main_blueprint
app.register_blueprint(main_blueprint)

return app

Routes and Blueprints

Now, let’s add the routes for our app. We’ll use two blueprints – one for our main routes and another for our authentication routes.

main.py

from flask import Blueprint

main = Blueprint(‘main’, __name__)

@main.route(‘/’)
def index():
return ‘Index’

@main.route(‘/profile’)
def profile():
return ‘Profile’

auth.py

from flask import Blueprint

auth = Blueprint(‘auth’, __name__)

@auth.route(‘/login’)
def login():
return ‘Login’

@auth.route(‘/signup’)
def signup():
return ‘Signup’

@auth.route(‘/logout’)
def logout():
return ‘Logout’

Templates

Next, we need to create the templates that will be used in our app. We’ll have four templates for our pages (index.html, login.html, profile.html, and signup.html) and one base template that will contain common code for all pages.

base.html