Dockerfile

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

WORKDIR /build

COPY requirements.txt .

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

# Install Python packages
RUN pip install --no-cache-dir --upgrade pip setuptools wheel \
    && pip install --no-cache-dir gunicorn \
    && pip install --no-cache-dir -r requirements.txt


# ---- Final Stage ----
FROM python:3.11-slim-bookworm

WORKDIR /app

# Runtime-only dependencies (minimal!)
RUN apt-get update && \
    apt-get install -y --no-install-recommends \
        libpq5 \
    && rm -rf /var/lib/apt/lists/*

# Copy installed packages and gunicorn from builder
COPY --from=builder /usr/local/lib/python3.11/site-packages/ /usr/local/lib/python3.11/site-packages/
COPY --from=builder /usr/local/bin/gunicorn /usr/local/bin/gunicorn

# Copy app source
COPY . .

# Create non-root user
RUN useradd -m -u 1000 appuser && \
    chown -R appuser:appuser /app

USER appuser

ENV FLASK_APP=app \
    FLASK_ENV=production \
    PYTHONUNBUFFERED=1 \
    PYTHONDONTWRITEBYTECODE=1

EXPOSE 5000

# Use a lighter healthcheck (Python-based)
HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
    CMD python -c "import requests; exit(0) if requests.get('http://localhost:5000/').ok else exit(1)" || exit 1

CMD ["gunicorn", "--bind", "0.0.0.0:5000", "--workers", "4", "--timeout", "120", "app:create_app()"]