Dockerfile

# Hugging Face Spaces dual-interpreter template for BeatNet.
#
# - Python 3.10 frontend: Gradio / pyharp app, listening on $PORT.
# - Python 3.9 backend: BeatNet + madmom worker, isolated in its own venv.
# - IPC: JSON-over-Unix-domain-socket; audio is passed by file path.

FROM python:3.10-slim-bullseye

ENV DEBIAN_FRONTEND=noninteractive \
    PYTHONUNBUFFERED=1 \
    PYTHONIOENCODING=UTF-8 \
    PIP_NO_BUILD_ISOLATION=1 \
    FRONTEND_VENV=/opt/frontend-py310 \
    BACKEND_VENV=/opt/backend-py39 \
    BACKEND_PYTHON=/opt/backend-py39/bin/python \
    BACKEND_SCRIPT=/app/backend_worker.py \
    PORT=7860

RUN apt-get update && apt-get install -y --no-install-recommends \
        build-essential \
        curl \
        git \
        libasound2-dev \
        portaudio19-dev \
        python3.9 \
        python3.9-dev \
        python3.9-distutils \
        python3.9-venv \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /app

# Backend uses Debian Bullseye's Python 3.9 interpreter for BeatNet/madmom.
# madmom is installed unpatched because the Space no longer runs it under 3.10+.
COPY requirements-backend-py39.txt /tmp/requirements-backend-py39.txt
RUN /usr/bin/python3.9 -m venv "$BACKEND_VENV" \
    && "$BACKEND_VENV/bin/pip" install --no-cache-dir -U pip wheel "Cython<3" \
    && "$BACKEND_VENV/bin/pip" install --no-cache-dir setuptools==80.9.0 \
    && "$BACKEND_VENV/bin/pip" install --no-cache-dir -r /tmp/requirements-backend-py39.txt \
    && "$BACKEND_VENV/bin/pip" install --no-cache-dir --no-build-isolation --no-deps madmom \
    && "$BACKEND_VENV/bin/pip" install --no-cache-dir --no-build-isolation --no-deps BeatNet \
    && "$BACKEND_VENV/bin/python" -c "import numpy; import madmom.audio.comb_filters; from BeatNet.BeatNet import BeatNet; print('backend import check ok', numpy.__version__)"

# Frontend uses the base image's Python 3.10 interpreter for Gradio/pyharp.
COPY requirements-frontend-py310.txt /tmp/requirements-frontend-py310.txt
RUN /usr/local/bin/python3.10 -m venv "$FRONTEND_VENV" \
    && "$FRONTEND_VENV/bin/pip" install --no-cache-dir -U pip wheel \
    && "$FRONTEND_VENV/bin/pip" install --no-cache-dir -r /tmp/requirements-frontend-py310.txt

COPY backend_worker.py frontend_app.py start.sh ./
RUN chmod +x /app/start.sh

EXPOSE 7860
CMD ["/app/start.sh"]