using docker BUILDKIT example, cache pip and mount temp whl to install. tensorflow python3.6

minimize_docker_python_application

# syntax = docker/dockerfile:experimental

FROM python:3.6 as base

######################################
FROM base as builder

ENV PYTHONPATH=$PYTHONPATH:/install/lib/python3.6/site-packages/

# bind a wheel and install it 
# tensforflow build without avx
# https://github.com/RainJayTsai/tensorflow-build/releases/download/v1.12.1/tensorflow-1.12.1-cp36-cp36m-linux_x86_64.whl
RUN --mount=type=bind,target=/tensorflow-1.12.1-cp36-cp36m-linux_x86_64.whl,src=./tensorflow-1.12.1-cp36-cp36m-linux_x86_64.whl \
    --mount=type=cache,target=/root/.cache/pip \
    pip install --prefix /install /tensorflow-1.12.1-cp36-cp36m-linux_x86_64.whl

WORKDIR /tmp_install

# bind a pipenv and install
RUN --mount=type=bind,target=./Pipfile,src=./Pipfile \
    --mount=type=bind,target=./Pipfile.lock,src=./Pipfile.lock \
    --mount=type=cache,target=/root/.cache/pip \
    && pip install pipenv \
    && pipenv lock -r | sed 1d > ./requirements.txt \
    && pip install --prefix /install -r ./requirements.txt
    
RUN --mount=type=cache,target=/root/.cache/pip \
    set -ex && ls -alg /root/.cache/pip && \
    pip install --prefix /install rasa-core && \
    ls -alg /root/.cache/pip

###########################################################
FROM python:3.6-slim as production

# copy install models and package to runtime image
COPY --from=builder /install/ /usr/local/

export DOCKER_BUILDKIT=1
docker build --rm -t xxxx/image:tag .