Non-root power management without DE?

statikregimen

Hello,

This is an awkward question - I'm not sure where to categorize it, so here it is

The actual underlying question is probably more like, "is there any way to allow a user to run some commands without sudo and without entering a password"? If not, I shall pursue the sudo route.

The more specific problem I'm trying to solve, is that I'd like to set up my "non-DE" with some way to automatically suspend+lock with an idle timer, and allow non-root users to suspend/shutdown/reboot. I would be curious to know how actual DE's handle this?

I'm using XDM+Qtile, with Xautolock+Slock. I've managed to get suspend and screen locking working w/ the laptop lid and/or power button, but that's not enough, nor am I pleased with the set up. Right now, it only locks after the Xautolock timer, so if the machine is woken up before it kicks in, the screen is not locked. I was unable to get slock to engage instantly through /etc/acpi configs - at best, it would do nothing; at worst the machine would freeze. Ideally, ANY time the system is put to sleep by any means (power button, lid, direct command), it should lock the screen with it (even more ideally, it should lock any tty sessions as well).

I spent a few hours last night and today googling but came up empty. Seems that since 99% of Linux users run proper desktop environments, most/all of the solutions were specific to those.

As always, any help/insight/advice is much appreciated!

Cheers.

khayyam · Posted: Thu Apr 05, 2018 11:20 pm Post subject:

statikregimen ...

the fact that the machines "freezes" may be a sign that the underlying mechanism (I assume swsusp) is unreliable, there may be an issue with some driver that doesn't suspend well (and you may need to make sure that its unloaded/loaded on suspend/resume).

That said you haven't stated what you're using (ie, sys-power/suspend, or sys-power/hibernate-script, etc) and what you're doing in /etc/acpi. I doubt you're using pm-utils, or upower, but it'd help to know what components you're currently working with.

As for slock, it's probably a case of needing to provide the DISPLAY environment variable, and user of that display. I'm not sure about xautolock but I would suspect there is a command to 'lock now', and most likely this also need to be provided DISPLAY and the user.

I can probably help in some way or other, but lets see what you're doing first. BTW, if you search for keywords 'acpid' and author 'khayyam' It'll probably bring up some examples of the above ... if you're in a rush.

I should note that I'm using tuxonice, sys-power/hibernate-script, sys-power/acpid, and don't use a DE (or the standard pm-utils/upower-pm-utils combination) ... so I've probably encountered some of the issues you're currently stuck on. However I don't lock the display, I suspend to an LVM swap within an dm-crypt volume.

best ... khay

statikregimen · Posted: Fri Apr 06, 2018 1:18 am Post subject:

Hu · Moderator Joined: 06 Mar 2007 Posts: 21602

If you're not happy with where you started the thread, it can be moved. For fastest service, report your own thread as being misplaced. Alternately, a clear enough statement of intent in the thread itself may catch a moderator's eye and get it moved. In this case, I'm not sure whether you want to move the entire thread or open a new post for the freezing problem and keep this thread focused on making automatic lock behave as you want. Please advise, and I can move accordingly.

The Doctor · Moderator Joined: 27 Jul 2010 Posts: 2678

The answer of how a DE does this is usually going to be a combination of policykit and sudo.

I'd stick with sudo. It is easy enough to configure it to run only specific commands and require a password or not according to taste.
_________________
First things first, but not necessarily in that order.

Apologies if I take a while to respond. I'm currently working on the dematerialization circuit for my blue box.

khayyam · Posted: Fri Apr 06, 2018 12:46 pm Post subject:

statikregimen · Posted: Fri Apr 06, 2018 3:08 pm Post subject:

khayyam · Posted: Fri Apr 06, 2018 9:59 pm Post subject:

Hu · Moderator Joined: 06 Mar 2007 Posts: 21602

You're getting reasonable responses in this forum, so I am inclined not to move the thread.

Mainline has working suspend-to-RAM and suspend-to-disk for most machines. You only need a kernel patch if your specific system is unsupported or if you want something more complicated than mainline can handle.

Standard advice for using an encrypted root filesystem in conjunction with hibernation is that the swap device be encrypted, so that anyone who wants to resume the system must know the swap password. This only helps for suspend-to-disk. For suspend-to-RAM, you still need to solve the problem here relating to locking the console.

statikregimen · Posted: Mon Apr 09, 2018 4:52 pm Post subject:

I did end up with laptop-mode-tools, from following the wiki. However, I uninstalled it, to no effect. I've set no other dpms options myself. It's not a big deal to script the backlight manually, so I will check out that thread you linked (I still have to work out the special 'fn' buttons on the keyboard to control it as well).

I didn't have much time to mess with the suspend/lock issue over the weekend, but I stopped using slock for the interim and did not have any issues with lockups/display corruption. So today, I tried your script, and the first thing it did was crash with display corruption on resume. So I'm at a loss. It appears on the surface that as soon as I try to bring screen locking into the equation, it fails more often than not. I will try Xscreensaver, in case slock is just buggy, however, I can't see how it would be /that/ buggy. It works fine as long as I don't suspend afterward.

khayyam · Posted: Mon Apr 09, 2018 8:51 pm Post subject:

statikregimen · Posted: Wed Apr 11, 2018 2:32 pm Post subject:

So far, this works fairly reliably: http://meaninglessinfo.com/tech/meaningless_desktop/etc_acpi_default2.txt

Basically, I have to get very specific with it, which is suboptimal for portability, but I can probably figure it out from here unless you know the answer

I guess the reason I'm getting the wrong user for the su command, is because I'm using XDM which is started automatically during boot, and is thus running as root.

Also, what is the significance of the Xauthority stuff? I omitted that for the same reason - root's home dir is not in /home, and also root is not the droids we're looking for.

I have no idea how or if any of this is related to the freezing, but lo and behold, I have not had it happen since changing the script like that, and my screen is getting locked every time now.

Cheers and thanks

khayyam · Posted: Wed Apr 11, 2018 8:56 pm Post subject:

statikregimen · Posted: Mon Apr 23, 2018 11:50 pm Post subject:

After several days of observation, the crashing returned, showing how truly intermittent it is. So, I took slock out of the equation. All seemed well until today, it froze again. With slock, it ranges from black screen w/ backlight to just noise on the screen. Without slock, it seems to fully bring the screen and whatever was last on it back but is otherwise unresponsive.

Going to pour back over everything in this thread and the other, to ensure I've tried all the suggestions so far, but looks like the issue never had anything to do w/ slock, like it seemed at first

khayyam · Posted: Tue Apr 24, 2018 12:45 am Post subject:

statikregimen ...

does anything get logged to /var/log/messages ... or whatever log swsusp logs to?

If you don't have any reason not to, you might give suspend2/tuxonice a try, it's part of sys-kernel/pf-sources (ebuild for 4.16_p3 can be found here).

best ... khay