PERSONAL NOTES:

Investigate if the following is possible: grab pristine file from /etc and change it to fit your needs without 'forcing' your customized file in the /usr/etc in here (n)or relying on just shenanigans

my-ublue

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

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.

Note Everywhere in this repository, make sure to replace throwaway43/my-ublue with the details of your own repository. Unless you used create-ublue-image, 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 recipe.yml. It's documented using comments and should be pretty easy to understand.

For the base-image field, you can use any other native container image. You will get all the features of that image, plus the ones added here! Check out the uBlue images list to decide what to use!

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. If you need to add other directories, you can look at the Containerfile to see how it's done. Writing to /etc or /var in Fedora's immutable OSTree-based distros isn't supported and will not work, as those are user-managed locations!

Note The configuration files you put in /usr/etc/ will automatically be applied to your local /etc/ by systemd whenever you rebase an OSTree system or update the image. If a config file in /etc/ has been modified (compared to the same deployment's defaults), then OSTree won't overwrite it, but the new version will be available in /usr/etc/. Run sudo ostree admin config-diff to see the difference between /etc/ and /usr/etc/ (man ostree-admin-config-diff for further documentation).

Custom build scripts

If you want to execute custom shell scripts or commands in the image build, you shouldn't edit the scripts/build.sh or the Containerfile directly.

Instead, you should create your own custom shell scripts in the scripts/ directory (look at the example.sh). After creating your scripts, enable them in the scripts: section of your recipe.yml, within the specific "build stage" category where the scripts are intended to be executed. Alternatively, enable the autorun.sh helper script in your recipe to automatically execute your custom scripts.

Read the README in the scripts/ directory for more information.

Custom package repositories

If you want to add custom package repositories to your image, you can include them in the recipe.yml as a list of URLs under the rpm.repos: section. They must be proper .repo files (such as https://copr.fedorainfracloud.org/coprs/atim/starship/repo/fedora-38/atim-starship-fedora-38.repo). In the build process, the .repo file will be downloaded and placed inside /etc/yum.repos.d/ where rpm-ostree can access it.

You can use this to add COPR repositories to your image. COPR is like the Arch User Repository for Fedora, where you can find extra packages that wouldn't otherwise be available. The repositories are community-created, so use them at your own risk. Read more

Tip: You can use the magic string %FEDORA_VERSION% in your repo URLs, to automatically refer to the correct repository for your current Fedora version.

If your .repo file is not available as a hosted URL and you need to copy it manually, you can upload the file in your github repository or a gist and add the raw link to the file under rpm.repos:. Another option in this scenario would be to create a folder for .repo files in your repository and add COPY repos /etc/yum.repos.d/ in the Containerfile.

Building multiple images

You can build multiple images using multiple recipe.yml files. They will share the Containerfile and everything else, but things like packages declared in the recipe will be different between the images. For a more robust multibuild setup, you could consider forking from the ublue-os/main repo, which was built from the purpose.

In order to build multiple recipes, you need to declare each one below line ~33 in build.yml. The files should be in the root of the repository.

Example: Adding a new recipe called recipe-2.yml (snippets from the matrix section of build.yml)

Before:

matrix:
  recipe:
    - recipe.yml

After:

matrix:
  recipe:
    - recipe.yml
    - recipe-2.yml

yafti

yafti is the uBlue "first boot" installer. It shows up the first time a user logs into uBlue. By default, the menu also shows up again anytime the image's yafti configuration differs from the user's last encounter, so feel free to expand or modify your custom image's yafti configuration over time. Your users will then see the yafti menu again after the OS update, and will be given a chance to install any new additions.

Its configuration can be found in /usr/share/ublue-os/firstboot/yafti.yml of the installed OS. It includes an optional selection of Flatpaks to install, along with a new group that's automatically added for all Flatpaks declared in recipe.yml. You can look at what's done in the yafti.yml config and modify it to your liking (in the repository, before building the image, since the installed system file is immutable).

If you want to completely disable yafti, simply set the recipe's firstboot.yafti flag to false, which then removes all yafti-related files and configurations from your final image. The files in usr/share/ublue-os/firstboot/ are responsible for automatically running yafti at login, and they will only be bundled in your image if yafti is enabled in your recipe!

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 image unsigned, to get the proper signing keys and policies installed:

  sudo rpm-ostree rebase ostree-unverified-registry:ghcr.io/throwaway43/my-ublue:latest
  

• Reboot to complete the rebase:

  systemctl reboot
  

• Then rebase to the signed image, like so:

  sudo rpm-ostree rebase ostree-image-signed:docker://ghcr.io/throwaway43/my-ublue: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:

sudo rpm-ostree rebase ostree-image-signed:docker://ghcr.io/throwaway43/my-ublue: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 throwaway43/my-ublue 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 task runner is included in ublue-os/main-derived images, and we have provided several template commands which help you perform further customization after first boot.

You can merge our template justfiles into your own local configuration. When just supports include directives, you will instead be able to simply include these paths into your own justfile, without having to copy anything manually.

Run the following commands when you're logged into the operating system, to merge uBlue's provided configurations into your own user config. (The "touch" command is only necessary on certain shells which won't let you merge into non-existent files.)

touch ~/.justfile
cat /usr/share/ublue-os/just/main.just >> ~/.justfile
cat /usr/share/ublue-os/just/custom.just >> ~/.justfile

After doing that, you'll be able to run the following commands:

• just - Show all tasks, more will be added in the future
• just bios - Reboot into the system bios (Useful for dualbooting)
• just changelogs - Show the changelogs of the pending update
• Set up distroboxes for the following images:
  • just distrobox-boxkit
  • just distrobox-debian
  • just distrobox-opensuse
  • just distrobox-ubuntu
• just setup-flatpaks - Install all of the flatpaks declared in recipe.yml
• just setup-gaming - Install Steam, Heroic Game Launcher, OBS Studio, Discord, Boatswain, Bottles, and ProtonUp-Qt. MangoHud is installed and enabled by default, hit right Shift-F12 to toggle
• just nix-me-up - Install Nix with dnkmmr69420's Nix Silverblue install script
• just update - Update rpm-ostree, flatpaks, and distroboxes in one command

Check the just website for tips on modifying and adding your own recipes.