Dockerfile

# Use Python 3.11 slim image for better security and smaller size
FROM python:3.11-slim

# Set environment variables
ENV PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1 \
    PIP_NO_CACHE_DIR=1 \
    PIP_DISABLE_PIP_VERSION_CHECK=1

# Create non-root user for security
RUN groupadd -r appuser && useradd -r -g appuser appuser

# Set work directory
WORKDIR /app

# Install system dependencies
RUN apt-get update \
    && apt-get install -y --no-install-recommends \
        build-essential \
    && rm -rf /var/lib/apt/lists/*

# Copy requirements first for better caching
COPY requirements.txt .

# Install Python dependencies
RUN pip install --no-cache-dir -r requirements.txt

# Copy application code
COPY . .

# Change ownership to non-root user
RUN chown -R appuser:appuser /app
USER appuser

# Expose port
EXPOSE 8000

# Health check using Python
HEALTHCHECK --interval=30s --timeout=30s --start-period=5s --retries=3 \
    CMD python -c "import urllib.request; urllib.request.urlopen('http://localhost:8000/health')" || exit 1

# Use gunicorn for production
CMD ["gunicorn", "--bind", "0.0.0.0:8000", "--workers", "4", "--worker-class", "sync", "--timeout", "120", "--keep-alive", "5", "--max-requests", "1000", "--max-requests-jitter", "50", "app:app"]