Dockerfile

FROM --platform=linux/amd64 python:3.11-slim AS builder

WORKDIR /app

RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential \
    libpq-dev \
    && rm -rf /var/lib/apt/lists/*

RUN python -m venv /opt/venv
ENV PATH="/opt/venv/bin:$PATH"

COPY requirements.txt .
RUN pip install --no-cache-dir --upgrade pip && \
    pip install --no-cache-dir -r requirements.txt && \
    pip install --no-cache-dir gunicorn dj-database-url

FROM --platform=linux/amd64 python:3.11-slim

ENV PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1 \
    PATH="/opt/venv/bin:$PATH" \
    PORT=8000

WORKDIR /app

RUN apt-get update && apt-get install -y --no-install-recommends \
    libpq5 \
    && rm -rf /var/lib/apt/lists/* \
    && useradd --create-home --shell /bin/bash appuser

COPY --from=builder /opt/venv /opt/venv
COPY --chown=appuser:appuser . .

RUN mkdir -p /app/staticfiles /app/uploads && \
    chown -R appuser:appuser /app

# collectstatic needs a non-empty SECRET_KEY at build time; not the production key
RUN SECRET_KEY=collectstatic-placeholder python manage.py collectstatic --noinput --clear

USER appuser
EXPOSE 8000

CMD ["gunicorn", "--bind", "0.0.0.0:8000", "--workers", "2", "--threads", "4", \
     "--worker-class", "gthread", "--worker-tmp-dir", "/dev/shm", \
     "--access-logfile", "-", "--error-logfile", "-", "blog.wsgi:application"]