There is no great value here.  I don't want yet more environment variable passed through foreman_server.sh (path to the shared storage device, storage type, cluster member IPs...) especially for someone that might not use it.  This is why we will document that the user needs to edit the variables _as makes sense_ for their environment in the HA Mysql Host Group (this doc currently on RDO btw: http://openstack.redhat.com/Foreman_HA_Database ).  There is an argument they should just be empty but I like that the UI has values that indicate to the user what makes sense there.