I was learning to work with Flask, SQLAlchemy and WTForms and Login Manager. So I created this simple auth app as reference to my future self and starting point for new apps. This example can be easily expanded to add new functions.

Setting up initial install

Let's start by cloning this repo:

$ git clone https://github.com/KingOfSpades/...
$ cd pythonFlaskUserAndAuthExample

As always you should start with an empty venv, activate it and install the required dependancys:

$ python3 -m venv .venv
$ source .venv/bin/activate
$ pip install -r requirements.txt

Now start the app with make or run it manually:

$ make run

This will start the app on: https://127.0.0.1:5000. You will get an https error because we are using a custom certificate. After accepting this you should see a message that you should login. Follow the instuctions and crate an account. You can now login to the application.

Explaining the app

This is easy app tha relies on one (1) database model, a FlaskForm and a couple of routes.

The most important thing is that you need to be logged in to view the "backend". This is handeld by LoginManager. Users are stored in the DB with a hashed password using the generate_password_hash() method (see models.py).

Forms

We use two (2) simpel forms:

• A registration form (for creating new users)
• A login form (for login in to the app)

Neat things

A few nice things:

Clean app.py

The app.py is verry clean because we use the import method:

# app.py
...
import routes, models
...

Using SSL

This is enabled in app.py:

# app.py
# This will create an ad hoc cert
if __name__ == "__main__":
  app.run(ssl_context='adhoc')

You can also choose to create a custom certificate and parse that to the app. See https://blog.miguelgrinberg.com/post/running-your-flask-application-over-https

You can re-direct traffic to HTTPS in routes using:

# routes.py
...
return redirect(next_page) if next_page else redirect(url_for('index', _external=True, _scheme='https'))
...