Linux

Launching GNOME applications on SSH session

TL;DR:

Add these 2 lines to your .bashrc:

export $(dbus-launch –exit-with-session)
gnome-keyring-daemon -c pkcs11,secrets

Those 2 lines took me quite some Googling to figure out..

So I have X11 DISPLAY environment variable configured on my SSH session, and GUI applications like gvim runs ok, even QtCreator and Quartus etc. can show their GUI just fine. gedit takes a while but will eventually show up.

Then I was trying to launch gnome-terminal on my SSH session, which after a while gives me this error:

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# Error constructing proxy for org.gnome.Terminal:/org/gnome/Terminal/Factory0: Error calling StartServiceByName for org.gnome.Terminal: Timeout was reached

gnome-terminal is special that it actually asks the gnome-terminal-server daemon to display the GUI, gnome-terminal itself will just exit afterwards.

That error, now that I have found out the solution, I think it means it’s trying to launch the service/application though dbus, but was unable to connect. To fix it, either launch it through dbus-launch:

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dbus-launch gnome-terminal

Or declare dbus session environment variables as in TL;DR:
--exit-with-session is necessary otherwise dbus-daemon will be persistent after SSH session exits.

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export $(dbus-launch --exit-with-session)

Now the terminal UI shows up, but it took quite some time. It must be waiting on something that eventually timed out.
Only for the first time in each SSH session though, on subsequent launches the GUI shows up straight away.
To debug this, declare environment variable G_DBUS_DEBUG:

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G_DBUS_DEBUG=all gnome-terminal
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......
GDBus-debug:Call:
 >>>> ASYNC org.freedesktop.DBus.Properties.GetAll()
      on object /org/gnome/Terminal/Factory0
      owned by name :1.1 (serial 7)
......
GDBus-debug:Call:
 <<<< ASYNC COMPLETE org.freedesktop.DBus.Properties.GetAll()
      FAILED: Timeout was reached
......

While watching /var/log/syslog:

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Jun 22 21:41:44 zhiyb-Linux dbus-daemon[565554]: [session uid=1000 pid=565552] Activating service name='org.freedesktop.secrets' requested by ':1.3' (uid=1000 pid=565616 comm="/usr/libexec/xdg-desktop-portal ")
Jun 22 21:42:09 zhiyb-Linux xdg-desktop-por[565616]: Failed to create secret proxy: Error calling StartServiceByName for org.freedesktop.secrets: Timeout was reached
Jun 22 21:42:09 zhiyb-Linux xdg-desktop-por[565616]: No skeleton to export
Jun 22 21:42:09 zhiyb-Linux dbus-daemon[565554]: [session uid=1000 pid=565552] Successfully activated service 'org.freedesktop.portal.Desktop'

So, some sort of secret proxy timed out.. Turns out that’s the gnome-keyring sevice.
To fix this, launch gnome-keyring-daemon.
I noticed that it prints something like this:
SSH_AUTH_SOCK=/run/user/1000/keyring/ssh Which is environment variable declaration for SSH agent. However, the agent seems to be problematic when multiple SSH sessions are open and multiple gnome-keyring-daemon instances are running, so disable the SSH component:

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gnome-keyring-daemon -c pkcs11,secrets

Anyway, now gnome-terminal launches almost immediately every time, so I’m happy 🙂.

Some extra stuff:

Launching virt-manager and trying to connect to qemu:///system gives error:

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Unable to connect to libvirt qemu:///system.

authentication unavailable: no polkit agent available to authenticate action 'org.libvirt.unix.manage'

To fix this, launch a GNOME polkit agent in the background.
I’m using debian 11, so it’s here:

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/usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1 &

To force GPG to use console-mode pinentry, install pinentry-curses, then

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sudo update-alternatives --config pinentry