I thought today, about using Docker to setup virtual environments instead of using Pipenv because I'd like to learn Docker a bit. I watched some Python videos on it and all of these were setting up fastapi's which I don't need so I wanted to make a more generic dockerfile and yml file that I can come back to over and over again.

I created a dockerfile like below:

FROM python:3.12-slim

WORKDIR /code

COPY ./requirements.txt ./ RUN pip install --no-cache-dir -r requirements.txt

COPY ./src ./src

I created a docker-compose.yml file like below:

services:
  app: 
      build: . 
      container_name: py_env 
      volumes: 
          - .:/code

I ran the command docker compose up --build -d and had no errors, it said Container py_env Started but when doing docker ps there is no container and when using dev containers in VS code to try to attach to a running container it says there are no running containers to attach to.

What am I missing?