Dockerfile

FROM python:3.7

ENV PYTHONUNBUFFERED 1
ENV SHELL /bin/bash

# ------------------------------------------
# install necessary packages via apt-get:
# ------------------------------------------
RUN apt-get update && \
	apt-get install -y --no-install-recommends \
	libsasl2-dev python-dev libldap2-dev libssl-dev

RUN apt-get update && \
	apt-get install -y --no-install-recommends \
	graphicsmagick

# this is supposed to save memory:
RUN rm -rf /var/lib/apt/lists/*

# ------------------------------------------
# install python dependencies:
# ------------------------------------------
COPY requirements.txt "$INSTALL_DIR/"
RUN pip install -r requirements.txt