Dockerfile

# syntax=docker/dockerfile:1

# ---- Base image ---------------------------------------------------------
FROM python:3.12-slim AS base

# Keep Python lean and predictable in containers.
ENV PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1 \
    PIP_NO_CACHE_DIR=1 \
    PIP_DISABLE_PIP_VERSION_CHECK=1

WORKDIR /app

# Install dependencies first so this layer is cached unless requirements change.
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt

# Copy the application source.
COPY app ./app

# Run as a non-root user for safety.
RUN adduser --disabled-password --gecos "" appuser \
    && chown -R appuser:appuser /app
USER appuser

EXPOSE 8000

# Container-level health check hitting the app's /health endpoint.
HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
    CMD python -c "import urllib.request,sys; \
    sys.exit(0) if urllib.request.urlopen('http://localhost:8000/health').status==200 else sys.exit(1)"

CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000"]