配合 Python 程式的 Dockerfile

# syntax=docker/dockerfile:1
FROM python:3.12-slim

WORKDIR /app

# 1. 先只複製相依清單
COPY requirements.txt .

# 2. 裝相依（這層只在 requirements.txt 變動時才重建）
RUN pip install --no-cache-dir -r requirements.txt

# 3. 最後才複製原始碼（改 .py 不會讓上面的 pip install 重跑）
COPY . .

EXPOSE 8000
CMD ["python", "app.py"]

# syntax=docker/dockerfile:1
FROM python:3.12-slim AS builder
WORKDIR /app
RUN python3 -m venv /venv
ENV PATH="/venv/bin:$PATH"
RUN --mount=type=cache,target=/root/.cache/pip \
    --mount=type=bind,source=requirements.txt,target=requirements.txt \
    pip install -r requirements.txt

FROM python:3.12-slim
WORKDIR /app
COPY --from=builder /venv /venv
ENV PATH="/venv/bin:$PATH"
COPY . .
EXPOSE 8000
CMD ["python", "-m", "uvicorn", "app:app", "--host=0.0.0.0", "--port=8000"]

FROM python:3.12-slim AS builder
RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential libpq-dev \
    && rm -rf /var/lib/apt/lists/*
# ... pip install ...