Overview

The goal of this repository is to provide an easy-to-setup Flask backend API server for rapid prototyping/POC projects. This file layout is basically copied from traditional Java's file organisation, purely because of personal preferences. It has a few basic features, namely:

1. Configuration Management.
2. Session-based Authentication. (using Cookies)
3. ORM capability using flask-sqlalchemy.
4. Production ready HTTP server with Gunicorn.
5. Docker Compose for quick & easy deployment to container environments.

Project Layout

• wsgi.py is the entry point of the Flask application, that Gunicorn binds to.
• /controllers will contain all the api/controller routes that the front end requires.
• /models will contain the data access object definitions.
• /services will contain the business logic.
• /views will contain the wrappers for incoming request bodies or outgoing response bodies.
• /utilities contains everything in between; constants, database initialisations, etc.
• /configurations handles the external environmental configurations.

Configuration Management

• Configuration can be managed through /configuration/*.yaml files or through environment variables.
  • The keys in the environment variables should be the uppercased versions of their .yaml counterparts.
    • For example, if db_name is defined in your .yaml file, then the corresponding environment variable should be DB_NAME.
  • The naming convention for the configuration files is: {environment name}.yaml .
• You are encouraged to define configurations in the .yaml files, because:
  • They are used as the base values which will only be overridden if the corresponding environment variables are present.
  • Nested environmental variables are currently not yet supported.
• Although default files dev.yaml and docker-dev.yaml are provided, PLEASE REMEMBER TO NOT COMMIT PRODUCTION CONFIGURATIONS TO YOUR REMOTE REPOSITORIES.

Manual Setup

These instructions were tested to work on a Mac, but should work for most common unix based systems as well. Unless otherwise stated, these commands should be run in the root of this repository.

1. Set up a Python virtual environment, activate and install the necessary packages.

   python3 -m venv venv
   source venv/bin/activate
   pip3 install -r requirements.txt
   

   1. If you install other packages in the future, you can add them to the requirements.txt file.

      pip3 freeze > requirements.txt
      

2. Set up your database. You can easily configure the database settings via the /configurations folder. If you are using MySQL, you can replicate these steps:

   1. Download mysql 8.0.x using Homebrew, then start the MySQL server.

      brew install mysql@8.0
      brew services start mysql
      

   2. Create a database/schema for your data.

      mysql -u root < "create schema scaffold;"
      

3. Check and change the values in /configurations accordingly.

4. Export environment variables as necessary.

   export ENV=dev # Defaults to 'dev'
   export PORT=8080 # Defaults to '8080'
   

5. Start the Flask development server, or the Gunicorn WSGI server.

   flask run --host=127.0.0.1 --port=8080 # dev server
   # OR
   gunicorn --bind 127.0.0.1:8080 wsgi:app # Gunicorn WSGI server
   

Docker-Compose Setup

1. Install Docker through brew if you haven't already. Alternatively, you can also install Docker Desktop if you want to use its GUI.

   brew install docker
   

2. Build the Dockerfile located at the root of this directory within Docker-Compose.

   docker-compose build
   

3. Start Docker-Compose.

   docker-compose up
   

4. Stop Docker-Compose.

   docker-compose down
   

Useful Resources

• Blueprints
• Connecting to MySQL
• Python MySQL Driver Error
• One To Many, One To One and Many To Many relationships.