getting started with xpra

[nbecker]

Newbie here. I have been using x2go for quite some time. My environment is client Fedora 41, server Fedora 40. I'm looking for persistent sessions. On the client side running kde on wayland.

I tried installing from rpmfusion, but these versions seem pretty old (5.something) so I went ahead and did rpmbuild and installed. I also have added xpra repo to dnf which seems needed because rpmbuild did not build xpra-html5.

My plan was to start a server on the server side and connect from the remote client. Despite chatgpt's advice to try:

[server] xpra start :100 --start=xfce4-session --daemon=yes
[client] xpra attach ssh:nbecker8:100

The client kept saying attach failed until I randomly tried starting the server with
xpra start :100 --start=xfce4-session --daemon=yes --html=off

Then I could connect!

First trying xfce4 but it didn't work well. Main issue is that I can't see the panel for when apps on the remote go when they are minimized. This seems to work:
xpra start-desktop :100 --start=xfce4-session --daemon=yes --html=off --resize-display=1920x1080 --dpi=161

Except that the --dpi=161 seems to be ignored. At least, xdpyinfo on the remote reports dpi=96, but otherwise it is working.

On the other hand, starting a kde session does not work. If I start with
xpra start-desktop :100 --start=startplasma --daemon=yes --html=off --resize-display=1920x1080 --dpi=161
There are multiple problems. 1: the display is only 1024x768. 2: keys such as PgUp/PgDn are mapped to some strange characters

So I guess my best option for running a remote persistent desktop is using
xpra start-desktop :100 --start=xfce4-session --daemon=yes --html=off --resize-display=1920x1080 --dpi=161
and attach using
xpra attach ssh:nbecker8:100

I suppose the html5 stuff might be fun, but probably harder to make that work via remote ssh connection (and maybe not performant enough?)

Thanks for any advice,
Neal

[totaam]

I tried installing from rpmfusion, but these versions seem pretty old (5.something)

That's the LTS branch, not necessarily old if it is up to date:
https://github.com/Xpra-org/xpra/wiki/Versions

have added xpra repo to dnf which seems needed because rpmbuild did not build xpra-html5

You could also just build https://github.com/Xpra-org/xpra-html5 which is totally trivial, or install individual xpra packages rather than the full xpra metapackage.
More info here: https://github.com/Xpra-org/xpra/wiki/Download#sub-packages

xpra start :100 --start=xfce4-session --daemon=yes

xfce-session is a desktop environment, use a desktop session for that, not a seamless session.

FYI: --daemon=yes is the default, so this has no effect here.

xpra start :100 --start=xfce4-session --daemon=yes --html=off

This should make no material difference.
html=off won't have any impact unless you connect with a browser.

Except that the --dpi=161 seems to be ignored

Have you correctly installed all the packages from the xpra repository, including the patched dummy driver?
See also https://github.com/Xpra-org/xpra/blob/master/docs/Features/DPI.md

There are multiple problems.
1: the display is only 1024x768

Sounds like: #4384

2: keys such as PgUp/PgDn are mapped to some strange characters

Sounds like #4292

xpra start-desktop :100 --start=xfce4-session --daemon=yes --html=off --resize-display=1920x1080 --dpi=161

As per above, --daemon=yes does nothing, neither does --html=off.

and attach using
xpra attach ssh:nbecker8:100

This syntax is ambiguous and has been deprecated for quite some time.
Up to date versions should warn you about it. Instead use: xpra attach ssh://user@host:sshport/DISPLAY.
Usually, the ssh port and display number can be omitted.

I would just run a single command directly from the client:
xpra desktop ssh://user@host/100 --start-child=xfce4-session --exit-with-children
So logging out from xfce would also end the session.

I suppose the html5 stuff might be fun, but probably harder to make that work via remote ssh connection (and maybe not performant enough?)

If you mean tunnelling via ssh, it just works as long as you keep your tunnel open.
As for performance, it varies a lot: it depends on the hardware you have (ie: GPU accelerated encoders?), and you need to be using SSL to enable hardware decoding in most browsers, etc.

[nbecker]

Thanks for your prompt help! I have gotten xfce working well now. One issue is it's convenient to start the xpra session from the client side: ```shell xpra desktop ***@***.***/100 --start-child=xfce4-session \ --exit-with-children --resize-display=1920x1100 ``` But this leaves the client shell with xpra in the foreground. If I detach using the xpra menu it works fine. Maybe not so clean if I forget to detach, close my laptop and go home. A second problem is starting kde. I can get it working with ```shell xpra desktop ***@***.***/100 --start-child=startplasma \ --exit-with-children --keyboard-raw=yes --resize-display=1920x1100 ``` Adding `keyboard-raw=yes` seems to fix my pgup/pgnd key mapping, but one problem remains. The display is always 1024x768, not resizeable, and the `--resize-display=1920x1100` is ignored.

[nbecker]

I spoke too soon. For the record I went back to the my distribution `xpra-5.0.10` packages. Using `xfce4-session` as describe above it is unusable, because PgUp and PgDn keys are wrongly mapped, exactly as described in #4292 Using `xev` shows exactly the same as in that report. I tried with `--keyboard-raw=yes` and that's worse. Now `PgUp=<kp-divide>`, `PgDn=<menu>`, but also the arrow keys are unusable, being mapped to modifiers such as `<AltR>`. OK, I removed all the 5.0.10 packages and reinstalled my `xpra-6.3-10.r37036.fc41.x86_64` packages. Now the keyboard is fixed! I guess I'll stick with these.

[totaam]

I tried with --keyboard-raw=yes and that's worse

As per the documentation, keyboard=raw can only work when both ends have the exact same configuration.
Wayland and X11 are not the same, so this cannot work.

I went back to the my distribution xpra-5.0.10 packages

5.0.10 is too old, the keyboard fix was merged in v5.0.11, specifically: 1b7a4ea

[nbecker]

Any way to get kde plasma going on the remote? I can start it, but it insists on 1024x768 ignoring the `--resize-display=1920x1200`. On startup I see: ``` 2025-01-03 08:32:23,057 Xpra X11 desktop server version 6.3 2025-01-03 08:32:23,057 remote desktop size is 1920x1100 2025-01-03 08:32:23,058 :101.0 (508x291 mm - DPI: 96x96) ``` And the initial kde splash screen is using the full display, but when kde finally shows the desktop it is stuck at 1024x768. Right click on background to set display shows highest resolution is 1024x768.

[totaam]

As per above, this sounds like #4384

[nbecker]

On Fri, Jan 3, 2025 at 10:48 AM Antoine Martin ***@***.***> wrote: As per above, this sounds like #4384 <#4384>

Thanks for your help. I guess it's a known issue. I'm fine using xfce for now, that at least seems to work.