Dockerfile

# Multi-stage Dockerfile for Project Management System
# Optimized for production deployment

# Stage 1: Build stage
FROM python:3.11-slim as builder

# Set working directory
WORKDIR /app

# Install system dependencies required for Python packages
RUN apt-get update && apt-get install -y --no-install-recommends \
    gcc \
    g++ \
    libpq-dev \
    && rm -rf /var/lib/apt/lists/*

# Copy production requirements first for better caching
COPY requirements-prod.txt .

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

# Stage 2: Runtime stage
FROM python:3.11-slim

# Set environment variables
ENV PYTHONUNBUFFERED=1 \
    PYTHONDONTWRITEBYTECODE=1 \
    FLASK_ENV=production \
    PORT=8000

# Create app user for security
RUN useradd -m -u 1000 appuser && \
    mkdir -p /app /app/instance /app/uploads /app/logs && \
    chown -R appuser:appuser /app

# Set working directory
WORKDIR /app

# Install runtime dependencies only
RUN apt-get update && apt-get install -y --no-install-recommends \
    libpq5 \
    curl \
    && rm -rf /var/lib/apt/lists/*

# Copy Python dependencies from builder
COPY --from=builder --chown=appuser:appuser /root/.local /home/appuser/.local

# Update PATH to include user-installed packages
ENV PATH=/home/appuser/.local/bin:$PATH

# Copy application code
COPY --chown=appuser:appuser . .

# Switch to non-root user
USER appuser

# Expose port
EXPOSE 8000

# Health check
HEALTHCHECK --interval=30s --timeout=10s --start-period=40s --retries=3 \
    CMD curl -f http://localhost:8000/health || exit 1

# Run the application using gunicorn
CMD ["gunicorn", "--bind", "0.0.0.0:8000", "--workers", "4", "--threads", "2", "--timeout", "120", "--access-logfile", "-", "--error-logfile", "-", "run:app"]