|From:||Brent Busby <brent@×××××××××.org>|
|Subject:||[gentoo-desktop] more kde-sunset upgrade notes|
|Date:||Thu, 14 Apr 2011 20:02:51|
Recently, I've updated to Gnome 2.32.1 on the same system that is also running KDE 3 from sunset. Keeping the two together on a machine that uses KDM 3.5.10 as a login manager is getting interesting. Here are some notes for those who may be in a similar situation: Recently, Gentoo decided to phase out Hal completely. Hal has been deprecated for some time, but now that pretty much all software that's officially supported from Gentoo's main package pool has been migrated to use Udev-based mechanisms, Gentoo decided to pull the plug on Hal. (Watching 2001 for the nth time might have caused them some anxiety about keeping Hal around any longer too...) Currently, Hal is still in Portage, but probably won't be much longer. I think someone mentioned pulling it into the kde-sunset overlay if it becomes necessary for KDE's sake. I've run into some issues on both the KDE 3 and the Gnome sides, which I'll mention separately. KDE 3 issues: The first trouble you'll have is that when Gentoo deprecated Hal, they also got rid of its USE flag, which means even from the kde-sunset overlay, KDE will build without Hal support, even if Hal is installed, and even if you have it enabled in your own USE flags. This will make removable media detection not work, even if hald is running. As it turns out, you can contradict the profile yourself by doing "-hal" again yourself in /etc/portage/profile/package.use.mask. The "-hal" from Gentoo and your own "-hal" cancel eachother out to effectively equal "hal" enabled. It's goofy, but it works. There are two packages in KDE that need it, so put this in that file: kde-base/kdebase-kioslaves -hal app-cdr/k3b -hal You should be able to keep your media detection in KDE now. Gnome issues: It should be mentioned at the start that 90% (if not all) of the issues below are caused by not using GDM as a login manager. Probably KDM 4 would work too, since it is receiving current support. However, XDM, KDM (3.x), and Slim will all have issues running Gnome now. Details follow... Recent versions of Gnome introduced us to PolicyKit, ConsoleKit, and lots of other assorted "kits" that run daemons we never had before, create lots of really ugly messages in syslog about DBus events nobody wants to know about (even on fully working systems that have only Gnome and no deviances), and provide services that nobody I know was asking for. In other words, desktop Linux evolution as usual... In the current version of Gnome though, PolicyKit and ConsoleKit have become serious. It's now necessary for PAM to run a module on every login called pam_ck_connector.so. This lets console-kit-daemon know you're logged in. Normally (for systems using GDM or KDM 4), the line in /etc/pam.d/system-login that does this contains the "nox11" parameter, because GDM is itself fully ConsoleKit-aware, and will provide its own plug to the console-kit-daemon without help from PAM. Thus, the "nox11" parameter inhibits the PAM plugin from working for cases of X logins, and makes it cover only TTY's: session optional pam_ck_connector.so nox11 (You probably got this line in your PAM config as part of an update, so it's probably already there. It's not necessary to do anything with it yourself, at least for normal systems.) However, the assumption that we're running a login manager that plugs into console-kit-daemon itself is false if we're running anything but GDM. (It's a Gnome world!) First, take the "nox11" part out of that line in /etc/pam.d/system-login. Then, since KDM has its own PAM config that doesn't source the system-login file at all (and thus is missing two needed lines), add the following to the bottom of /etc/pam.d/kde: session optional pam_loginuid.so session optional pam_ck_connector.so Ah, but we're not done. Now you need to modify the file that provides the login profile in KDM's session menu to choose Gnome. Normally, it just runs "gnome-session", but we need it to run "ck-launch-session gnome-session", so the Gnome launch gets connected to the session in ConsoleKit. (Isn't this nice?) This is not needed for any other window manager I use besides Gnome, so that's the only profile you'll need to adjust this way. Here's my adjusted /usr/share/xsessions/gnome.desktop: [Desktop Entry] Name=GNOME Comment=This session logs you into GNOME Exec=ck-launch-session gnome-session TryExec=ck-launch-session Icon= Type=Application If you do all of this, you should be able to type "ck-list-sessions" in Gnome and see your login listed as an x11 session, and most importantly, flagged as "active". Mounting removable media should work, though now via udev and udisks-daemon rather than hald. Oddly though, there still must be some magic that GDM would give me that KDM is not providing, because gnome-screensaver now cannot ever detect when the display has been idle long enough to start the screensaver on its own. If I lock the display myself, it works. The display even falls asleep on its own if left idle long enough, so power management is working -- although unlocked, and with no screensaver. It just turns off. A different system which also runs KDE 3 (from sunset) alongside modern Gnome does not have this problem. The difference between them is that it uses GDM for its login manager. GDM seems to do more here than meets the eye. The telltale error in syslog is: gnome-session: WARNING: GSIdleMonitor: Unable to initialize Sync extension There is nothing in Google about this other than a reference to the actual line in the code that generates the message. Basically, gnome-session is not able to connect to the X11 extension that tells how long the display has been idle. I have no idea why, or what GDM would ordinarily do that sets up this connection. The result though is that the screensaver will never kick in on its own, only under user control. PARTING THOUGHTS: Gnome is getting too complicated for its own good, and about to jump the shark that KDE just fell off of when 4.x came out. Obviously, the intent of all of this is to tie services to the user who is actually at the console. But why? Is it really a problem if my removable media is mounted by a remote user? Who says it is? Many times, I have left a DVD in my drive only to access the files on it from somewhere else, logged in on a shell via SSH. It's nice to not have to su to root to access that DVD. It's also nice to not assume I'm on a Gnome desktop using udev, pam_ck_connector.so, console-kit-daemon, ck-launch-session, and Nautilus to see that DVD. It used to be as simple as putting a line in /etc/fstab that allows that mount by regular users. Oh! But that was before they made it so that udev would not be able to automatically provide desktop icons or automounting in Gnome if you had such lines in your fstab. For awhile now, it's been necessary to remove lines for DVD's or USB flashdrives if you want Gnome desktop automounting to work. So we've gone from being able to mount a DVD from a bare shell as a regular user, to needing to be on a Gnome desktop, and from there to needing to be on a Gnome desktop that was launched in a ConsoleKit environment with a PAM connector module. Otherwise, you need to be root to mount a DVD. It's long been practice of the GNU Project to make versions of historically standard UNIX tools that have more features than the original did. Their tar is a super-tar, their ps is a super-ps, and so on. If we really needed more functionality for detecting who is logged in and from where, couldn't we have just revamped /var/log/wtmp, 'who', 'last', and related commands and programs to provide whatever was missing at the UNIX level, to benefit the whole system? Rather than just making more obtuse daemons that seem to be trying to make the whole system into one big platform to run Gnome? And if we need finer permissions to control mounting of media, here's a novel idea: Posix groups! Whoo! Why not just control who can mount with a group, and have the users who can do that controlled by some kind of group policy? Nah, too simple. You know, one of the big things that always stood in the way of FreeBSD being a decent desktop platform (even for technically oriented users) was that its fstab syntax has no equivalent to Linux's "users" option. There is only one even approaching-decent way to allow non-root users to mount media in FreeBSD, and that's to set up the Berkeley automounter ("amd" daemon) to do it for you with an automounter map. And as anyone who's ever dealt with the automounter knows, that's a fickle and tempermental solution sure to drive anyone crazy. You don't want to do that? Drop to a shell, and mount your disc as root! That's removable media in the world of FreeBSD on the desktop. Now, in Linux, thanks to the fact that Gnome/udev will not automount discs unless the fstab entry is *missing*, and thanks to the fact that Gnome further requires a PolicyKit/ConsoleKit environment to automount media also, even Linux machines with Gnome now have no option to mount removable media without resorting to some form of root access, via su, sudo, or hell why don't we just do what the BSD people do and run an automounter daemon? It's all taken care of if you're in Gnome or modern KDE (4.x), but that's now become an assumption. You can't even be just running a console anymore. It'd be nice if the people working on all these desktop technologies would remember that most things always were provided with basic UNIX tools, and if those tools aren't doing what's needed, they can usually just be given new features, like the GNU Project did with most of the standard userland. We don't need more daemons to interact with the other new daemons that we got because we needed to run more daemons. -- + Brent A. Busby + + Sr. UNIX Systems Admin + Vote for Cthulhu. + University of Chicago + + James Franck Institute + Why settle for the lesser evil?
|[gentoo-desktop] Re: more kde-sunset upgrade notes||Duncan <1i5t5.duncan@×××.net>|