Dockerfile

# Use Python 3.11 slim image
FROM python:3.11-slim

# Set environment variables
ENV PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1 \
    FLASK_APP=app.py \
    FLASK_ENV=production \
    PORT=5001

# Create and set working directory
WORKDIR /app

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

# Copy only requirements first to leverage Docker cache
COPY requirements.txt .

# Install Python dependencies with minimal size
RUN pip install --no-cache-dir -r requirements.txt \
    && find /usr/local/lib/python3.11/site-packages -name "*.pyc" -delete \
    && find /usr/local/lib/python3.11/site-packages -name "__pycache__" -delete

# Copy application code
COPY . .

# Create non-root user for security
RUN adduser --disabled-password --gecos '' appuser \
    && chown -R appuser:appuser /app
USER appuser

# Expose port
EXPOSE ${PORT}

# Health check
HEALTHCHECK --interval=30s --timeout=30s --start-period=5s --retries=3 \
    CMD curl -f http://localhost:${PORT}/health || exit 1

# Start Gunicorn
CMD gunicorn --bind 0.0.0.0:${PORT} \
    --workers=2 \
    --threads=4 \
    --worker-class=gthread \
    --worker-tmp-dir /dev/shm \
    --access-logfile - \
    --error-logfile - \
    app:app