I am running Fedora 28 and am attempting to disable the user list in GDM (as the machine is domain joined, this is undesirable). In CentOS 7 this is as simple as putting a file named "00-login-screen" in "/etc/dconf/db/gdm.d/" with the contents:
In this case, there is no "gdm.d" directory. Creating it, and then putting the file in the directory does not work. I've seen elsewhere that a file needs to be created in "/etc/dconf/profile" called "gdm", but I have created this file with the contents:
user-db:user system-db:gdm file-db:/usr/share/gdm/greeter-dconf-defaults
and it makes no difference.
Has the procedure changed that substantially in Gnome 3.28.2 compared to 3.22.2?
EDIT: This problem now occurs in CentOS 7 as well, likely due to a Gnome update.