So when you work with image mode, you should know how you add software to an image.
So how does that work?
Well, a system that has been installed with image mode is fundamentally different.
And as a result, only VAR and ETC are writable and all other directories are read-only.
Directories like slash home, slash MNT, slash root, and all of these are linked to the slash
VAR directory.
Now, if you want to install new software, you cannot use DNF.
You need to add it to the image that the system was installed from.
So on the system that has been installed with image mode, you can use sudo bootc status
to verify which image was used.
And if the image was updated, you can use sudo bootc status, and that will show you
that a rollback image is as well.
So how do we add software to an image mode environment?
Well, you need to go container file.
You apply your changes to the container file.
You rebuild the new image, and you push it to the image registry with a new tag.
And once available, you use bootc to update the installation, and you reboot once it is
done.
You can also take care of this in an automated way.
So on an image mode system, there is a system D service with the name bootc fetch supply
updates.
It's a timer, and that checks periodically if updates are available, and it will apply
them if this is necessary.
And if you want to go for the manual way, well, that's also possible that you disable
the timer, and you also would do that if you want to update using Ansible, for instance.
If you want to manually fetch updates, use bootc upgrade, and to only check if updates
are available, you sudo bootc upgrade minus minus check.
So sudo bootc upgrade minus minus check will check if anything is available, and if something
is available, you use sudo bootc upgrade to perform the actual upgrade.