Backend setup and architecture

First, make sure you have MySQL server and Python 3.x installed in your system. (the recommended version is python 3.9)

Installation instructions

• All the backend related required libraries are listed in the requirements.txt file. Before installing the libraries, install a python virtual environment. You can install the python virtual environment by following this guide. Follow the relevant guide based on your operating system.

• run the setup script using ./setup.sh to create a virtual environment and activate it.

• Then Active the virtual environment and run the following command to install the pip packages to your virtual environment.

pip install -r requirements.txt

• To set up the database, open your MySQL console and create a database. And add a .env file and add the following details as shown below.

secret_key = 'Your secret key'
db_name = 'database name'
db_host = 'host ip address'
db_password = 'database user password'
db_user = 'database username'

• set up the FLASK_APP environment variable:

export FLASK_APP=app.py

• Now the backend is ready to go ! You can run the backend by the following command.

python app.py or flask run

Application Architecture

The application architecture is set up as follows.

.
├── README.md
├── app.py
├── .env
├── .gitignore
├── config.yaml
├── endpoints
│   ├── DataProcess
│   ├── DataUpload
│   └── DeepLearning
├── requirements.txt
├── migrations
│   ├── README
│   ├── __pycache__
│   │   └── env.cpython-39.pyc
│   ├── alembic.ini
│   ├── env.py
│   ├── script.py.mako
│   └── versions
│       ├── db_migration_table_v1.py

├── setup
│   ├── settings.py
│   └── urls.py
├── shared
│   ├── request
│   │   └── response.py
│   ├── services
│   │   └── config.py
│   └── utils.py
├── static
├── templates
|__ tests
    |_ unit
    |_ test.csv
    |_ conftest.py

TODO: Describe architecture and how to do incremental developments.

Database modifications

Once you change to database models or create one, it will not affect as soon you have done it. You have to migrate the database accordingly. To migrate database, please follow the below steps.

• run flask db migrate This will generate migration scripts in migrations/versions directory.

• To apply migrations to the database, run flask db upgrade

• Don't forget to commit the generated migration scripts to code.

Testing

For the backend, PyTest is used for testing. Sample unit tests and configurations are added inside the tests directory. For database tests make sure to create a mock database and add a sample datafile using db_session and add_sample_file fixtures in conftest.py. To run backend tests simply run pytest . in the terminal.