Dockerfile

FROM python/3.7

# Install system dev packages
RUN apt update -y && \
    apt install -y libmariadbclient-dev gcc

# Build wheels of all our requirements
COPY requirements/requirements.txt requirements/requirements.txt
RUN mkdir wheels/ && \
    pip install -U pip && \
    pip wheel -w wheels/ -r requirements/requirements.txt

# Start with a clean image
FROM python/3.7

# Only install what we need for runtime
RUN apt update -y && \
    apt install -y libmariadbclient18 && \
    rm -rf /var/cache/apt/*
# This last line above cleans up apt's caches, to avoid image bloat

# Copy the wheels over from stage 0
COPY --from=0 wheels/ wheels/
RUN pip install -U pip && \
    pip install wheels/* && \
    rm -rf /root/.cache
# Again, remove the .cache to avoid image bloat. YMMV