Development ‐ Backend

Griddle's backend is an OpenAPI-enabled HTTP API written in python using FastAPI.

Development

Recommended IDE Setup

• VSCode + Black

Requirements

• Python 3.10
  • recommend using pyenv for managing python versions
• pipenv
  • (python -m pip install --user pipenv)
• Docker
• (if on Unix system) postgres libraries

Initial setup

We use FastAPI for our backend. To get started, cd into this backend folder, and create a virtualenv with our dependencies using pipenv install.

Running a development server

Make sure to spin up our development docker-compose.yml. To start up both a local postgres database and localstack (s3 simulator) run:

docker-compose up -d

Enter a shell using pipenv shell.

To start a dev server, run:

uvicorn main:app --reload

Troubleshooting

After the initial run of the commands above, you might encounter issues with dependency modules missing. Try running the commands below: (Make sure you are in virtualenv!)

pipenv requirements > requirements.txt
pip install -r requirements.txt

If there're still erros with modules such as uvicorn and bcrypt, pip install these packages individually, and then try starting the server.

Contributing

We use a couple libraries to streamline the creation of our backend API.

• FastAPI to build routes and handlers. This automatically generates OpenAPI docs which can be found at localhost:8000/docs. Most things you'd want to do are covered in their docs.

• SQLAlchemy to model and access our database.

• Alembic to auto-generate and run database migrations. These are kept in the migrations folder.

• boto3 to access S3 (or in our deployed case Cloudflare R2).

• sqladmin to view the DB with a nice web GUI. Can be found at localhost:8000/admin.

Here are some key files to get started:

• routers/api_v1/assets.py for routes that have to do with assets.

  • util/crud.py for CRUD logic used in the above file.

  • If updating routes, make sure to sync them with the frontend. See the frontend README for how to do this.

• database/models.py for our database models. Make sure to do matching edits to the below file.

  • schemas/models.py are Pydantic models that the routes and CRUD logic will use.

Migrations

When you're ready to make a full migration (change in the DB models) run the following in your virtualenv:

alembic revision --autogenerate

Then, commit the resulting autogenerated file in migrations.