Dockerfile.stage

# ============================================================
# Stage 1 — Builder (uv only)
# ============================================================
FROM python:3.13-slim AS builder

WORKDIR /app

# System deps for building native wheels (pandas, numpy, etc.)
RUN apt-get update && apt-get install -y --no-install-recommends \
    curl ca-certificates build-essential \
    && rm -rf /var/lib/apt/lists/*

# Install uv
RUN curl -LsSf https://astral.sh/uv/install.sh | sh
ENV PATH="/root/.local/bin:$PATH"

# Create venv
RUN uv venv /opt/venv
ENV PATH="/opt/venv/bin:$PATH"

WORKDIR /app

# Copy dependency file first (cache layer)
COPY requirements.txt .

# Install dependencies (ONLY ONCE)
RUN uv pip install --python /opt/venv/bin/python -r requirements.txt

# ============================================================
# Stage 2 — Runtime (distroless)
# ============================================================
FROM gcr.io/distroless/python3-debian12:nonroot

ARG BUILD_DATE="1970-01-01T00:00:00Z"
LABEL org.opencontainers.image.created="${BUILD_DATE}" \
      org.opencontainers.image.title="python-uv-distroless"

WORKDIR /app

# Copy venv from builder
COPY --from=builder /opt/venv /opt/venv

# Copy app
COPY hello.py /app/hello.py

# Runtime environment
ENV PATH="/opt/venv/bin:$PATH" \
    PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1

USER nonroot:nonroot

# Use system python OR venv python (both OK, venv is safer for reproducibility)
ENTRYPOINT ["/opt/venv/bin/python", "-u", "/app/hello.py"]