Dockerfile

# ── Stage 1: Builder ──────────────────────────────────────────────────────────
FROM python:3.11-slim AS builder

WORKDIR /build

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

# Copy and install Python dependencies
COPY requirements.txt .
RUN pip install --no-cache-dir --upgrade pip \
    && pip install --no-cache-dir --prefix=/install -r requirements.txt


# ── Stage 2: Runtime ──────────────────────────────────────────────────────────
FROM python:3.11-slim AS runtime

# Security: create non-root user
RUN groupadd --gid 1001 appgroup \
    && useradd --uid 1001 --gid appgroup --shell /bin/bash --create-home appuser

WORKDIR /app

# Copy installed packages from builder
COPY --from=builder /install /usr/local

# Copy application source
COPY app/ ./app/

# Set environment defaults (overridable at runtime)
ENV PYTHONUNBUFFERED=1 \
    PYTHONDONTWRITEBYTECODE=1 \
    ENVIRONMENT=production \
    PORT=8000

# Switch to non-root user
USER appuser

# Health check (aligns with Kubernetes probes)
HEALTHCHECK --interval=30s --timeout=10s --start-period=10s --retries=3 \
    CMD python -c "import urllib.request; urllib.request.urlopen('http://localhost:8000/health')" || exit 1

EXPOSE 8000

# Start FastAPI with Uvicorn
CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000", "--workers", "2"]