anchor.diff:  # IRODS icat server
   # install instructions: https://docs.irods.org/4.1.5/manual/installation
   WORKDIR /tmp
  -ENV IRODSVERSION 4.1.8
  +ENV IRODS4VERSION 1.9
  +ENV IRODSVERSION 4.$IRODS4VERSION
  +# note: there is no releases for ubuntu 16 at the moment...?
  +ENV OSVERSION ubuntu14
  +# ENV OSVERSION ubuntu16
   ENV IRODSFTP "ftp://ftp.renci.org/pub/irods"
   ENV IRODSRELEASES "$IRODSFTP/releases/$IRODSVERSION/ubuntu14"
  -RUN wget -q $IRODSRELEASES/irods-icat-${IRODSVERSION}-ubuntu14-x86_64.deb
  -RUN wget -q $IRODSRELEASES/irods-database-plugin-postgres-1.8-ubuntu14-x86_64.deb
  -ENV IRODSGSI "$IRODSFTP/plugins/irods_auth_plugin_gsi/1.2"
  +
  +RUN wget -q $IRODSRELEASES/irods-icat-${IRODSVERSION}-${OSVERSION}-x86_64.deb
  +RUN wget -q $IRODSRELEASES/irods-database-plugin-postgres-${IRODS4VERSION}-${OSVERSION}-x86_64.deb
  +ENV GSIVERSION 1.2
  +ENV IRODSGSI "$IRODSFTP/plugins/irods_auth_plugin_gsi/${GSIVERSION}"
   ENV IRODSGSI_DEB /tmp/gsi.deb
  -RUN wget -q $IRODSGSI/irods-auth-plugin-gsi-1.2-ubuntu14-x86_64.deb -O $IRODSGSI_DEB
  -
  +RUN wget -q $IRODSGSI/irods-auth-plugin-gsi-${GSIVERSION}-${OSVERSION}-x86_64.deb -O $IRODSGSI_DEB
   
   ##########################################################################
   # install scripts
  
positive.code: VOLUME /etc
  # VOLUME /etc/irods
  # VOLUME /etc/grid-security
  
  ##########################################################################
  # THE INIT PHASE IS NECESSARY OUTSIDE OF THE DOCKERFILE
  
negative.code: ##########################################################################
  FROM ubuntu:16.04
  MAINTAINER "Paolo D'Onorio De Meo <p.donoriodemeo@cineca.it>"
  
  ##########################################################################
  