12factor-todo

This is a simple TODO application to show the 12 Factor app patterns in action in Python.

Backing Services

The app depends on just Postgres. Any version of modern Postgres would do. For instructions on how to install Postgres on your operating system, have a look here.

Installing Dependencies

The application should run fine on Python 3.8+ as of September 1, 2020

$ git clone https://github.com/palnabarun/12factor-todo.git
$ cd 12factor-todo
$ python -m pip install pipenv
$ python -m pipenv install

Setting up the database

Once Postgres is installed, you have to create the database and the schema.

$ createdb todo
$ psql todo < schema/schema.sql

Running the application

Environment variables

Name	Description
PGHOST	Postgres server hostname. If not set, psycopg2 will use the Postgres unix socket.
PGPORT	Postgres server port. If host is set and port is not set, 5432 will be used as the default.
PGUSER	Postgres server username. If not set, takes in the current OS user.
PGPASSWORD	Password for the above Postgres User. Empty if not set.
PGDATABASE	Database name for the application. MUST BE SET.
WEB_CONCURRENCY	The number of workers uvicorn should spin up. If not set, 1 worker is spun up.

$ PGDATABASE=todo ./run_server.sh [--reload]

Optionally, you can pass in --reload to have the server live reload on changes.

Using the Docker image

With every tagged release of this GitHub repository a new Docker container is pushed to GitHub Container Registry. You can pull in and use the same.

$ docker pull ghcr.io/palnabarun/12factor-todo:<tag>
$ docker run --rm \
    --name 12factor
    --publish 8000:8000
    --env PGHOST=db.foo.com
    --env PGPORT=5432
    --env PGUSER=baz
    --env PGPASSWORD=qux
    --env PGDATABASE=todo
    ghcr.io/palnabarun/12factor-todo:<tag>

Talk

This app was built to show the 12factor patterns in PyCon India 2020. The draft presentation can be seen here.

License

This project is governed by the terms GNU GPLv3