fruppiOS

Warning

fruppiOS is in very early development. Expect breaking changes. Use it at your own risk.

Contents

• Philosophy
• Quickstart
• Pre-installed apps
• Desktop defaults
• Flatpak
• Nix
• Your own session
• Updates and rollback
• Building
• Possible additions
• Acknowledgements

Philosophy

fruppiOS is a Fedora Atomic desktop image for one person on their own machine. The image owns the base system: the desktop, system packages, and system configuration. You own what you add on top: apps, tools, and personal configuration. Your additions survive base system updates and rollback.

The desktop stays close to upstream defaults. Install GUI apps with Flatpak and terminal tools with Nix.

The base system updates itself and applies the update when you reboot. Flatpak apps don't. You update those yourself.

Quickstart

You need an existing Fedora Atomic installation, such as Silverblue. Keep these steps open somewhere else. fruppiOS has no browser until you install one.

1. Switch to fruppiOS

Your current installation doesn't have the fruppiOS signing key yet, so this first switch can't verify the image. The key comes with fruppiOS.

sudo bootc switch ghcr.io/trin94/fruppios:44
sudo systemctl reboot

2. Enable image verification

Log in and press Super+T to open the Ptyxis terminal. Switch again, this time with signature verification. All later updates are verified.

sudo bootc switch --enforce-container-sigpolicy ghcr.io/trin94/fruppios:44
sudo systemctl reboot

Use the 44 tag, not latest. 44 stays on Fedora 44 and is rebuilt daily. latest moves to the next Fedora release when the recipe does.

3. Install a browser

After the second reboot, log in and open the terminal again. Each account gets ~/fruppiOS-first-steps.txt on first login. Run the browser commands from that file. They add Flathub and install Firefox.

Press Super+D to open the launcher and start Firefox. New apps show up without logging out.

The file also has a few setup reminders. Delete it when you're done. It won't come back.

Coming from Silverblue? Its Flatpak remotes are still there. See Flatpak to remove them.

Pre-installed apps

The image is based on Fedora's base-atomic. Some packages, Noctalia among them, come from the Terra repository.

App or component	Role
niri	Wayland desktop
Noctalia	Desktop bar, launcher, and lock screen
Noctalia Greeter	Login screen
Ptyxis	Default terminal
Kitty	Alternative terminal
Nautilus	File manager
Flatpak	GUI app manager
Nix	Package manager for terminal tools

There's no browser.

Desktop defaults

On boot you get Noctalia Greeter. There's no autologin. After login, niri starts with the Noctalia bar.

Keys	Action
Super+T	Ptyxis terminal
Super+D	Noctalia launcher
Super+Alt+L	Lock
Super+Shift+/	niri hotkey overlay

The rest of the niri configuration is the upstream default.

The image also sets up:

• GNOME portals for the file chooser and screen sharing
• polkit prompts through Noctalia
• keyring unlock at login
• lock on suspend
• the standard home directories on first login, through xdg-user-dirs

Flatpak

Install more GUI apps with Flatpak. The image ships without remotes, so you choose where your apps come from.

A switch keeps your existing remotes and apps. If you came from Silverblue and don't want its Fedora remotes, remove them:

flatpak remote-delete --system fedora
flatpak remote-delete --system fedora-testing

Flatpak apps don't update automatically. Update them yourself:

flatpak update -y

Nix

Nix runs through the system daemon. Flakes and nix-command are already enabled, so there's nothing to install. To learn Nix, start with the official First steps guide.

Nix keeps its store, database, profiles, and garbage collection roots under /var/nix, outside the base system. The image bind-mounts that directory onto /nix, so Nix sees its usual paths.

Base system updates and rollback don't touch your Nix profiles. You update them yourself. The image doesn't pin nixpkgs.

Your own session

niri

niri uses ~/.config/niri/config.kdl if it exists, and /etc/niri/config.kdl otherwise. If you don't have your own file yet, start from the shipped one:

mkdir -p ~/.config/niri
cp /etc/niri/config.kdl ~/.config/niri/config.kdl

Edit the copy. niri reloads it live. Changes to the image's default won't replace your file.

Noctalia

Noctalia runs as the systemd user unit noctalia.service, tied to graphical-session.target. It starts when you log in and stops when the session ends. The image enables the unit. To turn it off or change it for your account without touching the niri configuration:

systemctl --user mask noctalia.service     # no bar from the next login on
systemctl --user unmask noctalia.service   # bar is back
systemctl --user edit noctalia.service     # drop-in under ~/.config/systemd/user/

Don't also start noctalia from your niri configuration. You'd get a second instance next to the unit.

Updates and rollback

Automatic base system updates

rpm-ostreed-automatic.timer runs 10 minutes after boot and then daily, with AutomaticUpdatePolicy=stage. It downloads the newest build of your tag and stages it for your next reboot.

Nothing reboots on its own. The image masks bootc's apply-and-reboot timer. Automatic updates only cover the base system, not Flatpak apps or Nix profiles.

Check the current deployments:

sudo bootc status      # booted, staged, rollback

Rollback

To boot the previous base system next time:

sudo bootc rollback
sudo systemctl reboot

Rollback only swaps the base system. Your home directory, Flatpak apps, and the Nix store live under /var and stay as they are. Rollback isn't a backup of them.

Two things to know:

• Each deployment has its own /etc. If you add a Wi-Fi profile or change a password after an update, rolling back brings back the old settings.
• Across major releases, a newer Nix daemon may migrate its database to a format an older daemon can't read.

Fedora releases and signatures

To move to a new Fedora release, run bootc switch --enforce-container-sigpolicy with its numbered tag, then reboot.

CI signs every published image with cosign. To verify an image yourself, use cosign.pub from this repository:

cosign verify --key cosign.pub ghcr.io/trin94/fruppios:44

Building

You need just and Podman. From a checkout of this repository:

just build

This starts your systemd user Podman socket and runs the BlueBuild CLI in a container against it. The build uses recipes/recipe.yml and the files under files/.

just build doesn't run the checks. Run them against a built image:

just test localhost/fruppios:latest

Every check runs, even after one fails. At the end you get a summary of what failed and a non-zero exit code.

To format and lint the repository, you also need uv:

just format

CI

• Builds on code pushes and daily at 06:00 UTC. Markdown-only pushes don't trigger a build.
• Runs just test on every build.
• On the default branch, if every check passes, pushes the image to GHCR and signs it. It then pulls the published image with the image's own signature policy.
• On other branches, builds and tests but doesn't publish.
• Runs just format on every push in its own workflow. A failing lint doesn't stop publishing.

Possible additions

Neither works today. I won't build them myself, but contributions are welcome:

• Homebrew as another way to install terminal tools.
• GUI apps through Nix, including the desktop integration they need.

Acknowledgements

fruppiOS mostly glues existing projects together with an image recipe and a few integration changes.

Thanks to the people behind:

• Fedora Atomic, bootc, and rpm-ostree for the base system and update tools.
• BlueBuild for the image build tooling.
• niri and Noctalia for the desktop.
• Nix and Flatpak for the tools to build the user environment.
• Terra for the packages it provides.