First we get with git 😉
If you are like me, you don’t want your template to have git, but only install it every time you need it ;), do the following and fedora-26 is polite and helps you out:
In appVM/dispVM, etc.
git clone https://github.com/tasket/Qubes-scripts.git
For now we only need the 1 script:
qvm-run --pass-io <src-vm> 'cat /path/to/file_in_src_domain' > /path/to/file_name_in_dom0
Now we have it in dom0:
We can try it out on a fedora-26 template:
./qubes4-multi-update -l fedora-26
Boom, already updated, but you get the picture.
The following command updates only templates with available updates. That should suffice for generic usage.
./qubes-multi-update -a -l -t
I found a small error when running an update on whonix-ws, but otherwise it runs beautifully.
When using Qubes 3.2 running the above command includes the standalone VM’s. Just so you know.