How can I execute a script after each update?

User Support
1

I would like to execute a script after each time my TemplateVM updates.

I tried /etc/qubes/post-install.d, but I don’t understand how it works.

Here is what I did:

  • Start a blank TemplateVM: (e.g.: fedora-38-xfce or debian-12-xfce)

In the TemplateVM:

  • Execute this:
$ cd /etc/qubes/post-install.d
$ sudo touch 05-write.sh
$ sudo chmod +x 05-write.sh
  • Write this in 05-write.sh:
#!/bin/sh

echo 'aaaa' > /tmp/a.txt

In dom0:

  • Start the Qubes Update GUI
  • Select the modified TemplateVM
  • Press Update

What I expect:

  • /tmp/a.txt exists and has aaaa in it.

What I happened:

  • Nothing

Question:

  • How can I execute a script after each update?
2

It works for me.
To note, if you run Qubes Update for this qube and restart the template after update then the file /tmp/a.txt won’t persist because /tmp directory is not persistent. Write to /home/user/a.txt for a test instead.
Also the script in /etc/qubes/post-install.d will only be executed if some package was installed during update. If there were no new updates then nothing will be executed.

3

In addition to what was said, these scripts will also be executed if you install a program from an AppVM (it’s something I often do, even if it’s not persistent).

You can add this to your script so it exits on non templates, this checks if there is a network interface and exits if so, a template shouldn’t have a network interface.

# abort if not in a template
ip l show eth0 && exit 0
1 Like
4

It’s not direct related, but you can parse rc.local.d directory on boot. See here:

5

It’s better to add this instead:

if test -f /run/qubes/this-is-templatevm ; then
   ## Do none of the following in a TemplateVM.
   exit 0
fi

Because in offline qubes there is no eth0 interface as well.

3 Likes
6

Perfect, I was looking for something more “template-only” :star_struck: :+1:

7

Try

qubesdb-read /type

Instead for this @solene :slight_smile:

8

this is even better :+1:

1 Like