Dockerfile

FROM python:3.11

# Install debugging tools
RUN apt-get update && apt-get install -y --no-install-recommends \
    strace \
    gdb \
    procps \
    curl \
    && rm -rf /var/lib/apt/lists/*

# Download the CPython GDB extension matching this Python version
RUN PYVER=$(python3 -c "import sys; print(f'{sys.version_info.major}.{sys.version_info.minor}.{sys.version_info.micro}')") && \
    curl -sSL -o /usr/local/bin/python3-gdb.py \
      "https://raw.githubusercontent.com/python/cpython/v${PYVER}/Tools/gdb/libpython.py" && \
    echo "add-auto-load-safe-path /usr/local/bin" >> /root/.gdbinit && \
    echo "source /usr/local/bin/python3-gdb.py" >> /root/.gdbinit

WORKDIR /app
COPY app.py .

EXPOSE 8080

# Use exec form so python is PID 1 (easy to strace/gdb attach)
CMD ["python3", "-u", "app.py"]