Dockerfile

# Use Python 3.9 slim-buster for stability and smaller footprint
FROM python:3.9-slim-buster AS builder

# Install system dependencies
RUN apt-get update && \
    apt-get install -y --no-install-recommends \
    gcc \
    python3-dev \
    libssl-dev \
    curl \
    && rm -rf /var/lib/apt/lists/*

# Create and activate virtual environment
RUN python -m venv /opt/venv
ENV PATH="/opt/venv/bin:$PATH"

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

# ========== Runtime Stage ========== #
FROM python:3.9-slim-buster

# Install runtime dependencies
RUN apt-get update && \
    apt-get install -y --no-install-recommends \
    libssl1.1 \
    curl \
    && rm -rf /var/lib/apt/lists/*

# Copy virtual environment from builder
COPY --from=builder /opt/venv /opt/venv
ENV PATH="/opt/venv/bin:$PATH"

# Create non-root user
RUN useradd -m -u 1001 krishna
USER krishna
WORKDIR /home/krishna/app

# Copy application code (with proper ownership)
COPY --chown=krishna:krishna . .

# Environment variables
ENV PORT=7860 \
    PYTHONUNBUFFERED=1 \
    PYTHONPATH=/home/krishna/app \
    GUNICORN_CMD_ARGS="--bind=0.0.0.0:7860 --workers=1 --threads=2 --timeout=120 --worker-class=gthread --log-level=info"

# Expose port and health check
EXPOSE 7860
HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3 \
    CMD curl -f http://localhost:7860/ || exit 1

# Run Gunicorn
CMD ["gunicorn", "app:app"]