Unable to set GDM Login Banner in RHEL7

Issue

• On RHEL 6 the following works from an RPM %post or with Satellite/Puppet to enable a custom GDM login banner:

  Set banner text

  banner="WARNING: Use of this system is Restricted and Monitored"
  

  Show the banner

  gconftool-2 --direct --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory --type string --set "/apps/gdm/simple-greeter/banner_message_text" "$banner" > /dev/null 2>&1 || :
  gconftool-2 --direct --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory --type bool --set "/apps/gdm/simple-greeter/banner_message_enable" "true" > /dev/null 2>&1 || :
  

• This does not seem to work with RHEL 7 any more.

• For many companies, it must be possible to enable GDM login banner due to company policies. It must be possible to do this during OS installation from a %post script (i.e., no dbus running on the system at that point) or with a simple script when the system is up and running. Login banner should work equally well for both native and fallback modes.