Issues with RedHat8 and XDG settings for desktop applications

[groucho64738]

Hi. I’m wondering if anyone has had a similar issue in getting VNC sessions started properly when using RedHat 8 cluster nodes.

I’m trying to launch the ‘fiji’ application (though it doesn’t really matter what the end application is), and I’m basing this on the bc_desktop launcher. The main issue is that while the application starts, there’s no window manager and ‘marco’ isn’t launching.

If I ssh into the cluster node, then launch the vnc app through ondemand, it does work with window decorations and all. I had this problem a long time ago with RedHat 7 systems and it came down to the unsetting of these environment variables in script.sh.erb:

unset XDG_RUNTIME_DIR
unset XDG_SESSION_ID
unset XDG_DATA_DIRS

This works fine for RH7 but doesn’t seem to work on RH8 in the same way. Has anyone encountered this?

Thanks.

[groucho64738]

wondering…does this have anything to do with the systemd --user stuff that might need to be in place for a user on RH8 that wasn’t there on redhat7.

[groucho64738]

I think I made progress on this issue. I made sure that my RedHat8 system had the ‘dbus-x11’ package installed. Then in my script.sh.erb file, I had this:

dbus-launch /usr/bin/marco --no-composite --no-force-fullscreen --sm-disable &

# mate-panel blocks, but does not work reliably when launched in the same subshell as marco
dbus-launch mate-panel &

So I just stuck the dbus-launch in front of the window manager commands and it seemed happy. Just putting it in front of mate-panel wasn’t enough (looks like marco went away). If I just put the dbus launch in front of marco and not mate-panel, the panel doesn’t come up. So, it seems like putting it in front of both was the way to go.

[jeff.ohrstrom]

Yea there are a couple of other topics related to RHEL 8 and these xfce scripts we launch (though I see you’re launching MATE instead).

In any case - the gist of them is that becuase of updates from RHEL 7 to 8 some commands don’t work the same anymore. They block and need to be backgrounded or they have different CLI options.

Do you need me to pull those topics for reference?

[groucho64738]

I had looked at the docs online with the configuration you have for matlab, and tried that as well, but generally had the same issue until I did the dbus-launch. If you can find those topics, it might be helpful as well.

Thanks.

[jeff.ohrstrom]

Here are a couple I found off the top of my head. Again though, they deal with XFCE, not MATE, but could be a similar issue as they are also RHEL 7 → 8 migrations.

Matlab Interactive App with Xfce and Rocky 8 RHEL/8

Hello, I am using OnDemand version: 2.0.31 and I’m halfway to getting the Interactive Matlab App working. With the usual script.sh.erb it doesn’t worked and i always got an Connection refused Error. I worked it around with help of other Discourse Topics where @JeffOhrstorm mentioned to put sleep in between the script. Now i get a Launch Button on the Interactive App Session page but when i start the VNC Session i cant see Matlab, but i can see the desktop. So when i start a Terminal from the de…

XFCE Windowing Issue With Interactive Apps

There is some issue in the way we wrote our apps and RHEL/8. Your OOD version has no affect on this issue. From the looks of your before.sh.erb you may have already seen these topics. I had to sprinkle in some sleep commands here and there. The last post on the MATLAB topic may be of interest too, it doesn’t have sleeps but also has eval $(dbus-launch --sh-syntax) which may be important in this context.

[groucho64738]

Yeah, these both are essentially the same solution (dbus-launch), guess my searching wasn’t particularly good.