How updates work

Luft isn’t a collection of packages that update one by one. Each version of the system is one sealed image, built and signed in one go, and an update swaps the whole system for the next version. Your files, settings and apps live apart from it and stay as they are.

This means an update either happens completely or not at all. A restart in the middle of downloading leaves the system you had, and if a new version doesn’t start, Luft goes back by itself.

Getting an update

Luft looks for updates every day and downloads them in the background. When one is ready, a notification says so.

1. Settings, Updates shows the new version, what’s new in it, when it was released and how much it downloads. Only the parts of the system that changed are downloaded.
2. Restart to install. The download waits until you restart or shut down.
3. The Restart and Power off dialogs have an Install version … box, ticked unless the battery is low. Leave it unticked and the update simply waits for another time.

The version you had stays on the computer as the previous version.

In Automatic updates you choose how often Luft looks (every day, every week, or only when you check) and whether it downloads in the background.

Going back

If something in a new version doesn’t suit you, Go back to the previous version in Settings, under Updates, makes the version before it start next time. Your files and settings stay as they are. While going back is queued, you can still choose to stay.

You can also go back while the computer starts: hold any key to show the boot menu, and pick the version under Previous versions.

When an update doesn’t start

A new version gets three tries to reach the login screen. If it doesn’t get there, Luft starts the version that last worked, explains what happened before the login screen, and doesn’t offer that update again; the next release replaces it.

Releases and nightly builds

	Comes	Follows
Releases	When a version is ready	ghcr.io/lantharos/luft:45
Nightly builds	Every night, when something changed	ghcr.io/lantharos/luft:45-nightly

A computer follows whatever it was installed from: a stick made from luft-nightly.iso keeps getting nightly builds. To move between them, run this in Tern and restart:

sudo bootc switch ghcr.io/lantharos/luft:45-nightly   # or :45 for releases

On a computer with NVIDIA graphics, add -nvidia to the end, such as :45-nightly-nvidia.

Firmware and apps

• Firmware for the computer and its devices also comes through Settings, under Updates, when the maker publishes it. Most firmware updates finish at the next restart.
• Apps aren’t part of the system image. Settings points to Schelf, which updates them.

From the command line

Command	Does
bootc status	Shows the running version, a downloaded one, and the previous one
sudo bootc upgrade	Downloads the newest version for the next restart
sudo bootc rollback	Starts the previous version next time