anchor.diff:  # START OPENVPN
   # TBD
   
  -# do not use the standard port
  -ENV PORT_OPENVPN 11194
  -EXPOSE $PORT_OPENVPN/tcp $PORT_OPENVPN/udp
  -
  +ENV PORT_OPENVPN 11194 # do not use the standard port
  +EXPOSE ${PORT_OPENVPN}/tcp ${PORT_OPENVPN}/udp
   
   # inspired by https://github.com/gaomd/docker-openvpn-static
   
  
positive.code: # START SQUID
  #
  ENV PORT_SQUID 13128
  EXPOSE $PORT_SQUID/tcp
  
  RUN apt-get update -qq && apt-get install -qqy \
        apache2-utils \
  
negative.code: # START SSH
  #
  
  ENV PORT_SSH 10022 # to prevent conflict with host ssh standard port when run in --net=host mode
  EXPOSE ${PORT_SSH}/tcp
  
  # Regenerate SSH host keys. baseimage-docker does not contain any, so you
  # have to do that yourself. You may also comment out this instruction; the
  