Make Docker image much much smaller

Dockerfile

@@ -1,8 +1,47 @@
-FROM python:3.9-slim-bookworm
-WORKDIR /app
+ARG PYTHON_VERSION=3.12
+
+FROM alpine AS python-builder
+ARG PYTHON_VERSION
+
+RUN apk add --no-cache python3~=${PYTHON_VERSION}
+WORKDIR /usr/lib/python${PYTHON_VERSION}
+RUN python -m compileall -o 2 .
+RUN find . -name "*.cpython-*.opt-2.pyc" | awk '{print $1, $1}' | sed 's/__pycache__\///2' | sed 's/.cpython-[0-9]\{2,\}.opt-2//2' | xargs -n 2 mv
+RUN find . -name "*.py" -delete
+RUN find . -name "__pycache__" -exec rm -r {} +
+
+
+FROM python:3.12.5-alpine3.20 AS app-builder
+
+RUN apk add swig \
+    linux-headers \
+    alpine-sdk \
+    cmake \
+    && wget http://abyz.me.uk/lg/lg.zip \
+    && unzip lg.zip && cd lg \
+    && sed -i -e 's/ldconfig/echo ldconfig disabled/g' Makefile \
+    && make \
+    && make install
+
 COPY requirements.txt ./
-RUN apt-get update && apt-get install build-essential -y
-RUN pip install --upgrade pip
-RUN pip install -r requirements.txt
+RUN pip install --no-cache-dir --no-cache -r requirements.txt
+
+RUN pip uninstall -y setuptools pip wheel
+RUN rm -rf /usr/local/lib/python3.12/site-packages/__pycache__ /usr/local/lib/python3.12/site-packages/_distutils_hack/
+
+
+FROM scratch
+ARG PYTHON_VERSION
+
+COPY --from=python-builder /usr/bin/python3 /
+COPY --from=python-builder /lib/ld-musl-*.so.1 /lib/
+COPY --from=python-builder /usr/lib/libffi.so.8 /usr/lib/
+COPY --from=python-builder /usr/lib/libpython${PYTHON_VERSION}.so.1.0 /usr/lib/libpython${PYTHON_VERSION}.so.1.0
+COPY --from=python-builder /usr/lib/python${PYTHON_VERSION}/ /usr/lib/python${PYTHON_VERSION}/
+COPY --from=app-builder /usr/local/lib/python${PYTHON_VERSION}/site-packages/ /usr/lib/python${PYTHON_VERSION}/site-packages/
+COPY --from=app-builder /usr/local/lib/liblgpio* /usr/lib/
+
+WORKDIR /app
 COPY src ./
-CMD ["python", "/app/main.py"]
+
+CMD ["/python3", "/app/main.py"]