Phos

Warning Startingpoint was recently rewritten, and this version is considered a "1.0" *semi-*stable release. There are breaking changes between this and the previous version. If you are merging changes from the previous (v0) version, please refer to the heads-up blog post.

This is a constantly updating template repository for creating a native container image designed to be customized however you want. GitHub will build your image for you, and then host it for you on ghcr.io. You then just tell your computer to boot off of that image. GitHub keeps 90 days worth image backups for you, thanks Microsoft!

For more info, check out the uBlue homepage and the main uBlue repo

Why the name

The immutable variants of Fedora are named after minerals (Silverblue, Kinoite, Onyx, etc), so I wanted to do the same for mine. I ended up choosing "Phos", a shorthand for Phosphophyllite. This was a homage to the main character of "Land of the Lustrous", which is probably my favorite story of all time.

Besides, "Phos" sounds a lot like FOSS, which is nice little hint at the role of Free Software in this project.

Getting started

See the Make Your Own-page in the documentation for quick setup instructions for setting up your own repository based on this template.

Don't worry, it only requires some basic knowledge about using the terminal and git.

After setup, it is recommended you update this README to describe your custom image.

Note Everywhere in this repository, make sure to replace pesader/phos with the details of your own repository. Unless you used one of the automatic repository setup tools in which case the previous repo identifier should already be your repo's details.

Warning To start, you must create a branch called live which is exclusively for your customizations. That is the only branch the GitHub workflow will deploy to your container registry. Don't make any changes to the original "template" branch. It should remain untouched. By using this branch structure, you ensure a clear separation between your own "published image" branch, your development branches, and the original upstream "template" branch. Periodically sync and fast-forward the upstream "template" branch to the most recent revision. Then, simply rebase your live branch onto the updated template to effortlessly incorporate the latest improvements into your own repository, without the need for any messy, manual "merge commits".

Customization

The easiest way to start customizing is by looking at and modifying config/recipe.yml. It's documented using comments and should be pretty easy to understand.

If you want to add custom configuration files, you can just add them in the /usr/etc/ directory, which is the official OSTree "configuration template" directory and will be applied to /etc/ on boot. config/files/usr is copied into your image's /usr by default. If you need to add other directories in the root of your image, that can be done using the files module. Writing to /var/ in the image builds of OSTree-based distros isn't supported and will not work, as that is a local user-managed directory!

For more information about customization, see the README in the config directory

Documentation around making custom images exists / should be written in two separate places:

The Tinkerer's Guide on the website for general documentation around making custom images, best practices, tutorials, and so on.
Inside this repository for documentation specific to the ins and outs of the template (like module documentation), and just some essential guidance on how to make custom images.

Installation

Warning This is an experimental feature and should not be used in production, try it in a VM for a while!

To rebase an existing Silverblue/Kinoite installation to the latest build:

First rebase to the unsigned image, to get the proper signing keys and policies installed:
```
rpm-ostree rebase ostree-unverified-registry:ghcr.io/pesader/phos:latest
```
Reboot to complete the rebase:
```
systemctl reboot
```

Then rebase to the signed image, like so:

rpm-ostree rebase ostree-image-signed:docker://ghcr.io/pesader/phos:latest

Reboot again to complete the installation
```
systemctl reboot
```

This repository builds date tags as well, so if you want to rebase to a particular day's build:

rpm-ostree rebase ostree-image-signed:docker://ghcr.io/pesader/phos:20230403

This repository by default also supports signing.

The latest tag will automatically point to the latest build. That build will still always use the Fedora version specified in recipe.yml, so you won't get accidentally updated to the next major version.

ISO

This template includes a simple Github Action to build and release an ISO of your image.

To run the action, simply edit the boot_menu.yml by changing all the references to startingpoint to your repository. This should trigger the action automatically.

The Action uses isogenerator and works in a similar manner to the official Universal Blue ISO. If you have any issues, you should first check the documentation page on installation. The ISO is a netinstaller and should always pull the latest version of your image.

Note that this release-iso action is not a replacement for a full-blown release automation like release-please.

`just`

The just command runner is included in all ublue-os/main-derived images.

You need to have a ~/.justfile with the following contents and just aliased to just --unstable (default in posix-compatible shells on ublue) to get started with just locally.

!include /usr/share/ublue-os/just/main.just
!include /usr/share/ublue-os/just/nvidia.just
!include /usr/share/ublue-os/just/custom.just

Then type just to list the just recipes available.

The file /usr/share/ublue-os/just/custom.just is intended for the custom just commands (recipes) you wish to include in your image. By default, it includes the justfiles from ublue-os/bling, if you wish to disable that, you need to just remove the line that includes bling.just.

See the just-page in the Universal Blue documentation for more information.