Warning: Recommending to use a virtual environment

[collabnix]

WARNING: Running pip as the 'root' user can result in broken permissions and conflicting behaviour with the system package manager. It is recommended to use a virtual environment instead: https://pip.pypa.io/warnings/venv

Something like the Multi-Stage build might be a good idea:

#temp stage
FROM python:3.9-slim as builder
WORKDIR /app
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1
RUN python -m pip install --upgrade pip
RUN python -m venv /opt/venv
ENV PATH="/opt/venv/bin:$PATH"
COPY requirements.txt /app
RUN pip install -r requirements.txt

# final stage
FROM python:3.9-slim
COPY --from=builder /opt/venv /opt/venv
WORKDIR /app
ENV PATH="/opt/venv/bin:$PATH"
COPY . /app/
EXPOSE 8000
CMD ["python", "manage.py", "runserver", "0.0.0.0:8000"]

I haven't tested it yet.

[aerabi]

I agree with using virtualenv inside the container, but I'm not sure about using a multi-stage build. It seems to me that the first and second stages have the same things in them: Python, virtualenv, and all the packages.