Removing flatpaks with default-flatpaks@v2

[DecentM]

I'm using blue-build in a weekly GH action to build on top of Aurora. This week I noticed that it failed because I still have the v1 config format. While upgrading, I noticed there's no remove option in v2.

With v1, I use the remove option to clean up some flatpaks that come with Aurora I don't want. Is there a way to achieve this with v2 at all? That is, to prevent a previous layer from installing some flatpaks.

I know I have the option of adding @v1 in the config, and also to adopt v1 as a custom module, but if at all possible, I'd like to use the newest builtin module while keeping this short list of flatpaks I don't want from getting installed.

[xynydev]

The problem here is that Flatpaks, without special extra trickery, cannot be installed at build-time or into a layer of a custom image. This would require setting a custom Flatpak install root, and the Flatpaks installed this way would not be removable by users.

As such, most images install Flatpaks in either or both of these ways:

1. Include Flatpaks in the ISO and an optionally runnable script or ujust recipe to install default Flatpaks manually
2. Include a systemd service to automatically install a list of Flatpaks on each boot

(1) is what most ublue images use, and it works well with public images since it is unsurprising to users; no removed system Flatpaks get re-installed automatically, and especially no manually added Flatpaks are removed automatically.
(2) is the method used by BlueBuild, because it works well for our users, many of which are rebasing onto their image and not installing from ISO, and among which it is also common to use the image only for one's personal computer, so changes in installed Flatpak lists are not surprising.

(that is not to say that both methods could be useful for both use cases)

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I consider automatic Flatpak removal on boot as it was implemented in v1 a possible anti-feature.

If your custom image has multiple users, removing Flatpaks from their systems on boot would not be a good user experience for the simple reason that you cannot know if the user was using that app or not. If you set a Flatpak to remove on each boot, and later a user realizes they need it and install it themselves, that manually installed Flatpak would also get removed. An image maintainer of an image with multiple users should carefully consider their options before deciding to ship such a script.

If you are the only user (or it at least is the case that you know how every one of your installations is being used), on the other hand, you can be more reckless. In this case, you could easily ship a script or a boot service to remove unnecessary Flatpaks from all your installations, or just manually remove them when you decide you don't need them.

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Looking at the Aurora repo, it seems to me that it is using method 1 only, but correct me if I'm wrong. Regardless, here are some suggestions:

• When the base images installs Flatpaks with method 1
  • If your base image includes Flatpaks you do not want in the ISO installer, but does not automatically install Flatpaks after the first boot, just build your own ISO without the Flatpaks you don't want (or a clean ISO without any Flatpaks and install them in other ways)
  • If your base image includes Flatpaks you do not want in the ISO installer, and does not automatically install Flatpaks after the first boot, but you already have an installed system and just want to rebase to your custom image, remove the unwanted Flatpaks manually
  • You are also free to make a script that runs on boot and removes unwanted Flatpaks, if you decide that that option is the best for you
• When the base images installs Flatpaks with method 2
  • If your image includes an automatic Flatpak installation system, modify it to not install unwanted Flatpaks, or remove it completely
  • From systems where the Flatpaks have already been installed, remove them manually or optionally with a script
  • Do no install new systems by rebasing from your base image, you should instead build an ISO of your custom image
  • Absolutely do not opt to skip all the steps outlined above and just ship a script that removes unwanted Flatpaks on boot, this script will likely run at the same time as the automatic Flatpak installation script and cause your systems to both install and remove the same Flatpaks on every boot (or, I mean, I guess you could do it if you like to look at your computer fight itself)

[DecentM]

Thanks for the detailed response! While I do sometimes like to watch computers fight, they're usually more roomba-shaped in that case! 😆

I hadn't yet considered using something other than modules to solve this issue, so after some digging in the Aurora repo, it seems they're shipping a text file at /etc/ublue-os/system-flatpaks.list, which is read by a script on startup to take care of installing flatpaks. So I can just change that file and the existing script should in theory pick it up, without needing to remove the already shipped solution.