Exemplar multi-stage build for a very large Python project

Dockerfile

FROM python:3.6.8-slim as base

RUN python -m venv /appenv

ENV PATH=/appenv/bin:$PATH

RUN pip install -U pip

# Only for old Docker versions
ENV TINI_VERSION v0.18.0
ADD https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini /tini
RUN chmod +x /tini

# -------------------------------------------------------------------------------------

FROM base as wheels

RUN apt-get update && apt-get install -y --no-install-recommends build-essential

RUN pip install wheel

# ?
COPY deploy/wheelhouse /wheelhouse

# Generate all wheels
ENV PIP_WHEEL_DIR=/wheelhouse
ENV PIP_FIND_LINKS=/wheelhouse
COPY requirements.txt requirements.txt
RUN pip wheel -r requirements.txt;

# Package the application for later installation (APPNAME)
COPY . /application
RUN pip wheel /application;

# Use external wheelcache, e.g. on CodeFresh
VOLUME /wheelcache
CMD ["sh", "-c", "cp /wheelhouse/* /wheelcache"]

# -------------------------------------------------------------------------------------

FROM base as install

COPY --from=wheels /wheelhouse /wheelhouse

COPY requirements.txt requirements.txt

RUN pip install --no-index -f /wheelhouse -r requirements.txt; \
    pip install --no-index -f /wheelhouse APPNAME

# -------------------------------------------------------------------------------------

FROM base as installed

COPY --from=install /appenv /appenv

# -------------------------------------------------------------------------------------

FROM installed AS adminserver

EXPOSE 80 443
ENTRYPOINT ["/tini", "--"]
CMD ["gunicorn", "-w", "2", "-b", "0.0.0.0:80", "api.admin:app", "--log-level=info", "--access-logfile=-"]