docker build -t example --build-arg ssh_prv_key="$(cat ~/.ssh/id_rsa)" --build-arg ssh_pub_key="$(cat ~/.ssh/id_rsa.pub)" --squash .
FROM python:3.6-slim
ARG ssh_prv_key
ARG ssh_pub_key
RUN apt-get update && \
apt-get install -y \
git \
openssh-server \
libmysqlclient-dev
# Authorize SSH Host
RUN mkdir -p /root/.ssh && \
chmod 0700 /root/.ssh && \
ssh-keyscan github.com > /root/.ssh/known_hosts
# Add the keys and set permissions
RUN echo "$ssh_prv_key" > /root/.ssh/id_rsa && \
echo "$ssh_pub_key" > /root/.ssh/id_rsa.pub && \
chmod 600 /root/.ssh/id_rsa && \
chmod 600 /root/.ssh/id_rsa.pub
# Avoid cache purge by adding requirements first
ADD ./requirements.txt /app/requirements.txt
WORKDIR /app/
RUN pip install -r requirements.txt
# Remove SSH keys
RUN rm -rf /root/.ssh/
# Add the rest of the files
ADD . .
CMD python manage.py runserver
If you're using Docker 1.13 and have experimental features on you can append --squash to the build command which will merge the layers, removing the SSH keys and hiding them from docker history.