anchor.diff:  ADD renewcron /etc/cron.d/renewcron 
   RUN chmod u+x /etc/cron.d/renewcron 
   
  -# Add script which runs when the service starts
   ADD servicestart /root/servicestart
   RUN chmod u+x /root/servicestart
   
  
positive.code: CMD ["bin/bash", "/root/servicestart"]
  
  EXPOSE 80
  
  
negative.code: #use 16.04 lts, install certbot-auto to get newest certbot version
  FROM ubuntu:16.04
  
  #set default env variables
  ENV DOMAIN_COUNT=0 \
      CERTBOT_EMAIL="" \
      PROXY_INSTANCE_NAME="proxy" \
      CERTBOT_CRON_RENEW="('0 3 * * *' '0 15* * *')" \
      PATH="$PATH:/root"
  
  # http://stackoverflow.com/questions/33548530/envsubst-command-getting-stuck-in-a-container
  RUN apt-get update && apt-get -y install cron && apt-get install -y supervisor && apt-get install -y wget && apt-get install -y curl
  
  # install certbot-auto
  RUN cd /root && wget https://dl.eff.org/certbot-auto
  RUN chmod a+x /root/certbot-auto
  RUN ./root/certbot-auto --version --non-interactive
  RUN PATH=$PATH:/root
  
  # Add supervisord.conf
  ADD supervisord.conf /etc/supervisor/conf.d/supervisord.conf 
  
  