Dockerfile

# --- Stage 1: Build Stage ---
FROM python:3.11-slim AS builder

# Prevent Python from writing .pyc files and enable unbuffered logging
ENV PYTHONDONTWRITEBYTECODE=1
ENV PYTHONUNBUFFERED=1

WORKDIR /app

# Install build dependencies only (will be discarded in the final image)
RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential \
    && rm -rf /var/lib/apt/lists/*

COPY requirements.txt .
# Install dependencies to a local directory
RUN pip install --no-cache-dir --user -r requirements.txt


# --- Stage 2: Final Runtime Stage ---
FROM python:3.11-slim AS runner

# Set environment variables
ENV PYTHONDONTWRITEBYTECODE=1
ENV PYTHONUNBUFFERED=1
ENV PATH="/home/appuser/.local/bin:${PATH}"

WORKDIR /app

# 1. Create a non-privileged system user
RUN groupadd -g 10001 appgroup && \
    useradd -u 10001 -g appgroup -s /bin/bash -m appuser

# 2. Install Tini (Init process to handle signals properly)
RUN apt-get update && apt-get install -y --no-install-recommends \
    tini \
    && rm -rf /var/lib/apt/lists/*

# 3. Copy only necessary artifacts from builder
COPY --from=builder --chown=appuser:appgroup /root/.local /home/appuser/.local
COPY --chown=appuser:appgroup . .

# 4. Switch to the non-root user
USER 10001

# 5. Expose port (Documentation only)
EXPOSE 8000

# 6. Use tini as entrypoint to manage zombie processes and signals
ENTRYPOINT ["/usr/bin/tini", "--"]

# 7. Run uvicorn with security-minded flags
CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000", "--no-access-log", "--proxy-headers"]