brunolnetto/sqlalchemy-docker

SQL Alchemy - minimum example

This is an example of how to use SQLAlchemy to connect to a PostgreSQL database. The example includes a database class that manages the connection and session, a model class that represents a table in the database, and a utility class that gets the database URI from environment variables. You can either use local or dockerized Postgres instance.

Preamble

1. Clone the repository with command run git clone git@github.com:brunolnetto/sqlalchemy-docker.git;

Make sure to install postgresql-contrib and postgresql-client for required postgres packages.

apt install postgresql-contrib postgresql-client

2. Install the dependencies: setup a virtual environment and install the dependencies

pip install virtualenv
virtualenv .venv
source .venv/bin/activate
pip install -r requirements.txt

Local Postgresql instance

Run main code with command .venv/bin/python3 backend/app/main.py.

Dockerized Postgresql instance

On the dockerized, you must first:

1. Host database instance with command run:

docker run --name db -e POSTGRES_PASSWORD=mypassword -e POSTGRES_USER=myuser -e POSTGRES_DBNAME=mydb -p 5433:5433 -d postgres

OR

docker compose up -d

2. Obtain container ip with command run docker inspect db | jq -r '.[0].NetworkSettings.Networks[].IPAddress';
3. Alter file .env with environment variables POSTGRES_HOST to container ip and POSTGRES_PORT as 5432 (the post on container network) by command run, below:

docker inspect db | jq -r '.[0].NetworkSettings.Networks[].IPAddress'

4. Run command .venv/bin/python3 app/main.py