I wrote:
I'm trying to setup a multi-user VNC server on recent versions of Fedora without success thus far. I understand that doing so requires a display manager with XDMCP support. The current default DM is SDDM which does not include such support (at least so far as I've found). That means I need to change the DM.
Following a suggestion I found somewhere, I ran "dnf install kdm; systemctl enable --force kdm.service". I chose KDM because the machines involved generally use KDE, not Gnome. That seems to be a painless substitution. However, I'm sure I'll have to install some protections against automatic updates that reverse the change.
Then I tried to follow the instructions in RH Bugzilla 1393971 (https://bugzilla.redhat.com/show_bug.cgi?id=1393971) and those at RH Solutions 2516 (for XDMCP with xinetd) and 2681531 (which replaces xinetd with a systemd socket). I also modified /etc/kde/kdm/Xaccess to uncomment "*". After this I get a connection but no login screen, just a blank screen with a momentary note about using F8.
The log shows several errors at different times in my experiments. Sometimes Plymouth is not running. Sometimes I'm told the VNC service got more than one socket. Usually KDM reports that it can't open the display, using an IPv6 notation for the display.
Can anyone point me to instructions which take into account systemd and the structure of recent Fedora releases? It seems to me likely that I've messed up something simple in trying to adapt the instructions (which are for xinetd and GDM). Or have I provided enough information to make a guess as to the problem?
On 07/06/17 19:51, Ed Greshko wrote:
This should help....
https://docs.fedoraproject.org/en-US/Fedora/21/html/System_Administrators_Gu...
Especially....
8.1.2.1. Configuring VNC Server for Two Users
Oh, and FWIW, I am currently running only a single user setup on an F25/KDE-Only system. No need to change sddm as your DM as that isn't what is being used by VNC.
Unfortunately, no, that doesn't help. I already have a one-user setup working and I understand how to extend it to additional users -- so long as the list of users is finite and known to me in advance. But the extension technique involves using unique ports for each user. It is not a properly scalable solution.
With the single-user approach, vncviewer directly asks the user for his password before initiating the connection. That's why it needs a unique port for each user. Using XDMCP with a display manager that supports it works differently. vncviewer doesn't ask for a password and initiates the connection immediately. The user is presented with the same graphical login screen a local user would see. Thus the number of users is not limited by anything I do setting up the configuration.
So, I'm still hoping someone here can help.