meticulous-backend

Introduction

This repository is used to run the backend of meticulous.

Backend: For Development

To allow developers to run the backend without a physical coffee machine, we have implemented a Docker configuration. Follow these steps:

Using Docker

# Branch
git fetch origin
git switch main

# Docker compose
docker compose run --build -p 8080:8080 backend

Running Directly on Linux

if you are on linux, just start the backend directly:

BACKEND=emulator python3 back.py

You can interact with the backend using the command line interface after run the docker compose command. For instance, you can enter the commands

l

and

r

to move the dial. These commands will shift the dial to the left or right, respectively.

Database Migrations Guide

This project uses Alembic for managing database migrations. Follow these steps to handle any changes in the database structure:

Making Database Changes

1. Modify Database Models:
   Edit database_models.py to reflect the required changes in your database structure. You can:

   • Add or modify tables, columns, or constraints.
   • Remember, this file is the single source of truth for the database schema.

2. Generate a Migration Script:
   Run the following command to create a new migration script:

   alembic revision --autogenerate -m "Brief description of change"

   • A new script will be generated in the alembic/versions directory.
   • Open the generated script and review the upgrade() and downgrade() functions.
   • Ensure these functions accurately reflect your intended changes, and modify them if necessary.

3. Apply the Migration:
   Update your local database to the latest version with:

   alembic upgrade head

Deployment

• Simply push your changes to the main branch.
• Other machines will automatically apply the migrations using the db_migration_updater.py script.

Rolling Back Changes

If you need to revert to a previous database version:

1. Identify the Revision:
   Find the desired revision ID from the scripts in the alembic/versions directory.

2. Set the Stable Version:
   Update the version in db_migration_updater.py:

   MIGRATION_VERSION_STABLE = "revision_id"  # e.g., "ebb6a77afd0e"

3. Automatic Downgrade:
   The system will automatically downgrade the database to the specified version.

Additional Notes

• Testing: Always test your migration scripts locally before deploying them.
• Collaboration: Communicate with your team when making significant changes to the database schema.
• Documentation: Keep your migration messages clear to track the evolution of the database.