Add gnome wayland support #44497

hedning · 2018-08-05T11:04:24Z

Motivation for this change

This adds support for launching gnome wayland sessions from GDM and SDDM, using the upstream session file. See #39871 and #32806 for some more discussion.

Edit: Updated against master now that gnome 3.30 is merged.

sessionCommand support

This should work quite well, but one remaining issue is the lack of support for displayManager.sessionCommands and therefore also gnome3.sessionPath. Some options here:

We could patch GDM, gnome-session, to run the wrapper for wayland-sessions too, not super happy about it, but might be good as it makes GDM act more like SDDM and LightDM.
Or we could move sessionCommands into /etc/profile checking for eg. XDG_SESSION_TYPE, but that seems really ugly.

Edit: We landed on simply not supporting sessionCommands on wayland for now.

patching gnome-session more?

6171bc0 might be better expressed by patching gnome-session to always look for session files in its own share/ folder.

Writing a test

Edit: gnome3-gdm now runs a wayland gnome session (GDM prefers the wayland session and we don't have a good way of telling it otherwise), so I ported it to work with wayland.

cc @jtojnar

Things done

Edit:

Tested succesfully in a VM (at a6c1ffe).
Ran gnome3, gnome3-gdm and sddm tests succesfully.
Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
Built on platform(s)
- NixOS
- macOS
- other Linux distributions
Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
Tested execution of all binary files (usually in ./result/bin/)
Determined the impact on package closure size (by running nix path-info -S before and after)
Fits CONTRIBUTING.md.

pkgs/desktops/gnome-3/core/gnome-session/fix-paths.patch

hedning · 2018-08-06T11:55:40Z

Replying to #39871 (comment) here instead.

I would not call the xsessionWrapper particularly elegant solution either. I would like to use the Xsession provided by GDM in the end.

Agreed, and in Gnome's case it seems the session is set up correctly with eg. pulseaudio, journal logging and dbus without the wrapper, mostly leaving /etc/profile which is sourced correctly. The only missing things seems to be sessionsCommands and graphical-session.target I think.

Any idea how to get the graphical-session.target running?

For what is worth, sessionPath might actually make sense outside of GNOME (e.g. for elementary), so moving it to /etc/profile should work.

True, there's not really any reason to switch on XDG_CURRENT_SESSION, users probably want functional software if they happen to currently run something else than Gnome. I'm guessing it even might make sense in a console session, as there could be cli tools requiring something exposed in these variables (probably not likely, but it shouldn't hurt).

As for sessionCommands, I would just add a comment it is not supported for sessions created from extraSessionFilePackages.

I'm not opposed to that. It should be noted that sessionCommands are currently sourced for X sessions from extraSessionFilePackages, due to the xsessionWrapper, so it's only wayland sessions that won't run it, which is even less breakage :)

Default session

One more problem, the wayland session have the same name as the xorg session (there's an extra session file that's explicitly for xorg) and seem to take priority. So people might end up «upgrading» to wayland without any warning which could be jarring.

jtojnar · 2018-08-06T12:54:42Z

Any idea how to get the graphical-session.target running?

Not sure. These might be relevant:

The following presentation looks extra interesting.

https://lists.freedesktop.org/archives/systemd-devel/2018-June/040952.html

True, there's not really any reason to switch on XDG_CURRENT_SESSION, users probably want functional software if they happen to currently run something else than Gnome.

For GNOME Flashback and Elementary, I have changed it to jtojnar@b5b2d8d but removal of the condition might make sense too.

I'm not opposed to that. It should be noted that sessionCommands are currently sourced for X sessions from extraSessionFilePackages, due to the xsessionWrapper.

Right. I would actually expect most of the things in the xsessionWrapper to be in the xsession instead. After all, upstream sessions should be launching most of these themselves, there should only be the Xorg things, see ${gnome3.gdm}/etc/gdm/Xsession.

So people might end up «upgrading» to wayland without any warning which could be jarring.

I would not worry about that. If the Wayland session fails to start for some reason, gnome-xorg will be selected automatically.

Actually, I am not sure GDM even respects default DE nixos option. I think it uses the user’s last selected one.

hedning · 2018-08-06T13:55:42Z

Hmm, so looks like we're abusing graphical-session.target. In that case I'm at least fine with breaking that in the wayland session.

Right. I would actually expect most of the things in the xsessionWrapper to be in the xsession instead. After all, upstream sessions should be launching most of these themselves, there should only be the Xorg things, see ${gnome3.gdm}/etc/gdm/Xsession.

Hmm, true, I didn't think that through fully when I wrote it. The wrapper should model gdm's Xsession more closely, though ${sessionCommands} will need to go there too. Perhaps out of scope of this PR, though could of course put it here anyway if it's wanted?

hedning · 2018-08-06T21:27:40Z

Another issue I bumped into (dogfooding the PR at the moment):

gnome-session launches a login shell using the user's preferred shell (as opposed to xsessionWrapper sourcing /etc/profile). In my case ZSH.

This results in any new interactive bash shells to source /etc/profile. In particular running nix run nixpkgs.some-package will result in an environment with a PATH that doesn't include the package. nix-shell is unaffected, so this might be a bug in nix, but it's never the less very sub-optimal. We're basically hitting a strange variant of #33219

The problem boils down to $__ETC_PROFILE_DONE never being set.

In lieu of /etc/environment we would probably need some sort of shell agnostic variant of __ETC_PROFILE_DONE that guards against sourcing the environment again for interactive shells.

We are patching GDM to respect GDM_SESSIONS_DIR environment variable, which we are setting in the GDM module. Previously, we only took care of a single code path, the one that handled session start-up; missing the one obtaining the list of sessions. This commit patches the second code path, and also whitelists the GDM_SESSIONS_DIR so that it can be passed to the greeter. Fixes #34101

bkchr · 2018-11-11T16:30:41Z

Any update on this pull request?

jtojnar · 2018-11-11T16:31:37Z

This is blocked by #45950 which is blocked by #46020

nathyong · 2018-12-04T23:56:36Z

What's the status on this now that gnome3 has been updated?

hedning · 2018-12-05T00:13:18Z

@nathyong gnome-3.30 is in staging-next, I'll fix up this PR when it hits master, then we should have wayland support pretty soon :)

…ackages

hedning · 2018-12-09T16:35:12Z

Ported the gnome3-gdm test to wayland (it broke since gdm prefers the wayland session. It's not super pretty, but should work, so we'll have test too :)

I think this should be ready now 🎉

lgtm

gnome-session inherits GDMS PATH, which is at the moment non-functional. In X11 this didn't matter as the `Xsession` wrapper would populate the environment beforehand. Wayland sessions doesn't source `Xesssion` (duh), so we patch `bin/gnome-session` to use absolute paths for `grep` and `bash`. In addition `bin/gnome-session` is a simple wrapper around `libexec/gnome-session-binary` mostly responsible for sourcing the users profile before launching the binary. This made our wrapping of `bin/gnome-session` ineffective on wayland as the profile would reset the environment. Simply wrap `libexec/gnome-session-binary` instead.

LightDM is unable to separate between `wayland-sessions/gnome.desktop` and `xsessions/gnome.desktop` so I ommitted adding this to LightDM.

This will simply make the `sessionPath` more likely to work.

This isn't strictly necessary yet as LightDM doesn't read the wayland sessions, but there's no harm in being explicit.

The test now runs wayland, which means we can no longer use X11 style testing. Instead we get gnome shell to execute javascript through its dbus interface.

hedning · 2018-12-10T09:46:25Z

Found a much simpler fix for gnome-session: simply wrap libexec/gnome-session-binary instead of bin/gnome-session, that way sourcing the profile in gnome-session won't clobber the wrapping environment.

Reran the tests, will merge later today if no one has any objections.

hedning · 2018-12-10T15:23:36Z

@GrahamcOfBorg build nixosTests.gnome3-gdm

hedning · 2018-12-10T15:55:33Z

The test timed out on ofborg, hopefully not due to testing for active gnome shell too early, putting too much pressure on the machine. Lets see how it dose on hydra.

hedning mentioned this pull request Aug 5, 2018

Investigate GNOME wayland support #32806

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GrahamcOfBorg added 6.topic: GNOME GNOME desktop environment and its underlying platform 6.topic: nixos 8.has: module (update) labels Aug 5, 2018

jtojnar previously requested changes Aug 5, 2018

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pkgs/desktops/gnome-3/core/gnome-session/fix-paths.patch Outdated Show resolved Hide resolved

GrahamcOfBorg added 10.rebuild-darwin: 0 10.rebuild-linux: 11-100 labels Aug 5, 2018

hedning force-pushed the gnome-upstream-wayland branch from 11ec0af to 8208ae1 Compare August 5, 2018 11:59

pSub added the 2.status: work-in-progress label Aug 5, 2018

jtojnar added this to GNOME/GTK specific in Wayland Aug 6, 2018

jtojnar added this to In Progress in GNOME Aug 6, 2018

hedning mentioned this pull request Aug 8, 2018

nixos/shells: Avoid overriding the environment for other child shells #44720

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jtojnar mentioned this pull request Aug 15, 2018

freedesktop modules: init #45058

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oxij mentioned this pull request Sep 5, 2018

nixos/shells: Avoid overriding the environment for other child shells #45784

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jtojnar mentioned this pull request Sep 28, 2018

Add GNOME Flashback support #47451

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hedning mentioned this pull request Oct 7, 2018

Add Wayland Support #5071

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nixos/displayManager: Install wayland sessions from extraSessionFileP…

9895ce2

…ackages

hedning force-pushed the gnome-upstream-wayland branch from 3636dbc to a6c1ffe Compare December 9, 2018 10:10

hedning requested a review from infinisil as a code owner December 9, 2018 10:10

GrahamcOfBorg added 10.rebuild-linux: 1-10 and removed 10.rebuild-linux: 11-100 labels Dec 9, 2018

hedning changed the title ~~[WIP] Add gnome wayland support~~ Add gnome wayland support Dec 9, 2018

hedning mentioned this pull request Dec 9, 2018

nixos/tests/i3wm: fix terminal title (test is broken on master) #51792

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hedning removed the 2.status: work-in-progress label Dec 9, 2018

hedning added the 2.status: work-in-progress label Dec 10, 2018

hedning added 5 commits December 10, 2018 10:36

nixos/sddm: Enable wayland-sessions

48a9a24

LightDM is unable to separate between `wayland-sessions/gnome.desktop` and `xsessions/gnome.desktop` so I ommitted adding this to LightDM.

nixos/gnome3: Implement sessionPath through environment.extraInit

cdd266c

This will simply make the `sessionPath` more likely to work.

nixos/displayManager: Note that sessionCommands aren't run on Wayland

3c0e704

nixos/tests/gnome3: select X11 gnome shell explicitely

116c16d

This isn't strictly necessary yet as LightDM doesn't read the wayland sessions, but there's no harm in being explicit.

nixos/tests/gnome3-gdm: port to wayland

75e223b

The test now runs wayland, which means we can no longer use X11 style testing. Instead we get gnome shell to execute javascript through its dbus interface.

hedning force-pushed the gnome-upstream-wayland branch from 098cbe8 to 75e223b Compare December 10, 2018 09:41

hedning removed the 2.status: work-in-progress label Dec 10, 2018

hedning merged commit 59d1fb6 into NixOS:master Dec 10, 2018

GNOME automation moved this from In Progress to Done Dec 10, 2018

jtojnar mentioned this pull request Jan 18, 2019

pantheon: init at 5.0 #48637

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hedning mentioned this pull request Mar 12, 2019

Plasma5: Use upstream xsession/wayland-session files #56988

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hedning deleted the gnome-upstream-wayland branch October 15, 2019 11:41

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Add gnome wayland support #44497

Add gnome wayland support #44497

hedning commented Aug 5, 2018 •

edited

hedning commented Aug 6, 2018

jtojnar commented Aug 6, 2018 •

edited

hedning commented Aug 6, 2018

hedning commented Aug 6, 2018

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jtojnar commented Nov 11, 2018

nathyong commented Dec 4, 2018

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hedning commented Dec 10, 2018

Add gnome wayland support #44497

Add gnome wayland support #44497

Conversation

hedning commented Aug 5, 2018 • edited

Motivation for this change

sessionCommand support

patching gnome-session more?

Writing a test

Things done

hedning commented Aug 6, 2018

Default session

jtojnar commented Aug 6, 2018 • edited

hedning commented Aug 6, 2018

hedning commented Aug 6, 2018

bkchr commented Nov 11, 2018

jtojnar commented Nov 11, 2018

nathyong commented Dec 4, 2018

hedning commented Dec 5, 2018

hedning commented Dec 9, 2018

hedning commented Dec 10, 2018

hedning commented Dec 10, 2018

hedning commented Dec 10, 2018

hedning commented Aug 5, 2018 •

edited

jtojnar commented Aug 6, 2018 •

edited