Cannot figure out how to start KDE properly under xrdp.

[allefeld]

I'm trying to start my standard KDE session under xrdp.
After a lot of googling, one hint seemed to work: put /usr/bin/startkde into ~/.Xclients.

Now KDE starts and is mostly okay, but I noticed some weirdness. For example, normally ~/.bash_profile has been executed somewhere during KDE start, so changes to PATH I made there are effective, e.g. inherited by shells running in a terminal window (Konsole). Since this is different, I'm wondering whether other things are, too.

What I would like to achieve is that xrdp starts a desktop session in the exact same way as a display manager like sddm does. Is that possible?

In case that is relevant, the computer runs Debian 10, with the included KDE Plasma 5.14.5 and xrdp 0.9.9.

[matt335672]

There will differences from a local session for two main reasons:-

1. The PATH is different on your version of xrdp . For more details see Xrdp session Kubuntu 20.04 , how to increase rights? #1773 from around this post, and the consequent Debian bug which was raised https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=984782. This is a Debian packaging issue, but you can work around it by making changes to /etc/xrdp/startwm.sh.
2. The permissions you get will be different because of a system feature called 'polkit'. Essentially, polkit realises you're in a remote session and limits what you can do. Here's a list of the issues raised by other users related to this feature. You'll need to work out which features you want to allow in your remote session and add polkit actions to enable them for 'implicit any' sessions.

[allefeld]

In other news, I switched from ~/.Xclients to ~/.xsession, and made that a proper bash script:

#!/bin/bash
. "$HOME/.bash_profile"
/usr/bin/startkde

That seems to work.

But I still don't understand why startkde doesn't execute ~/.bash_profile by itself. Because it assumes that has already been done? When?

[matt335672]

startkde is normally executed from a shell script run in the user's context. The shell will be a non-interactive login shell.

A shell started within KDE will be an interactive non-login shell, so the files that get run are different.

Both of these situations are described in the INVOCATION section of the bash manpage.

It's all rather confusing, and a lot of people just make .bashrc a symlink to .bash_profile (or vice-versa), and then use something like the following to decide what to run:-

if [[ $- = *i* ]]; then
    # Interactive shell
else
    # Non-interactive shell
fi

Go with whatever feels the most natural way for you.

[allefeld]

startkde is normally executed from a shell script run in the user's context. The shell will be a non-interactive login shell.

Hm, I'm still not sure I understand: Does "normally" include execution by xrdp? If yes, meaning xrdp runs a non-interactive login shell from which startkde is executed, that would mean that that shell reads ~/.bash_profile on startup, so that PATH etc. set there should be inherited by KDE. So why do I have to explicitly source it in my ~/.xsession?

Thanks for the tip about $- = *i*! My ~/.bashrc contains [ -z "$PS1" ] && return to stop processing for interactive shells, picked up at some point from somewhere, but your version is better.

[matt335672]

If you're on Debian, there's a problem with /etc/xrdp/startwm.sh not being run as a login shell (Fedora works around this differently). So although /etc/profile is scanned, ~/.bash_profile won't be. I think that explains why you need to source it in your ~/.xsession.

[allefeld]

Thanks for all your help!