Dockerfile

################ builder ################
FROM python:3.9-slim AS builder
WORKDIR /build

COPY requirements.txt .
RUN pip install --prefix=/install -r requirements.txt

COPY app.py .
RUN python -m compileall -b -f app.py          # → app.pyc
RUN tar -czf /build/app.tgz app.pyc            # bundle

################ runtime ################
FROM python:3.9-slim
WORKDIR /app

# bring in everything we need
COPY --from=builder /install /usr/local/
COPY --from=builder /build/app.tgz /app/app.tgz

ENV PYTHONUNBUFFERED=1         
EXPOSE 7860

# -------- no file, all inline --------
ENTRYPOINT ["bash", "-c", "\
  set -euo pipefail; \
  mkdir -p /tmp/runner; \
  cp /app/app.tgz /tmp/runner/; \
  tar -xzf /tmp/runner/app.tgz -C /tmp/runner; \
  python /tmp/runner/app.pyc & pid=$!; \
  sleep 2; \
  rm -f /tmp/runner/app.pyc /tmp/runner/app.tgz; \
  wait $pid"]