Schema migration with Flask

This template workspace gives the project structure to setup a flask web application, using SQLAlchemy, Flask-Migrate, Flask-Marshmallow and Pytest.

Alembic migrations are stored in the migrations folder by default.

This project was inspired and follows the same structure as another Flask example made by the youtuber Eduardo Mendes. My goal is to expand with more advanced configurations, including Docker and CI/CD.

Original video

His Youtube Channel

Source Code

Project Structure

This project features an flask app, defined as a package in the __init__.py file, the function create_app act as application factory and is automatically detected when flask run is executed (see the Flask tutorial for more details).

All database tables are expressed as classes in the models.py file, the function to setup the database is also defined in this file.

serializer.py contains the schemas to serialize every model.

hello_world.py defines a blueprint, which contains its own set of routes that can be registered to the app.

Lastly. the html that is rendered on the starting route is included in the templates folder

Configure Development Workspace

1. Set the environment variables

You can either add all your variables in a .env file or export them in a single terminal session.

You can create a secret key with the following command:

 openssl rand -hex 64

Then write on the .env file:

DATABASE_URI="<your_database_uri_here>"
SECRET_KEY="<your_secret_key>"

Or export on the terminal session:

• Linux

export DATABASE_URI="<your_database_uri_here>"
export SECRET_KEY="<your_secret_key>"

• Windows

setx DATABASE_URI="<your_database_uri_here>"
setx SECRET_KEY="<your_secret_key>"

2. Install dev_requirements

pip install -r dev_requirements.txt

3. Upgrade the database to latest migration

flask db upgrade

4. Configure your self-signed ssl certificate for the development environment

To create a self signed certificate you can execute this openssl command:

openssl req -x509 -newkey rsa:4096 -nodes -out cert.pem -keyout key.pem -days 365 

You can answer the questions made with . (blank) or any value you prefer, it will be used only on development.

5. Run the app locally

flask run --debug --cert cert.pem --key key.pem

TODO

• Containerize the application
• Set up dependabot
• Configure docker compose with Nginx
• Configure logging
• Style the hello page