Use a different source for our os-release vars

[Itxaka]

Kairos version:

latest, ubuntu

CPU architecture, OS, and Version:

all

Describe the bug

if someone creates a derivative version and upgrade the system, there is a possibility of the upgrade overwriting the os-release file, which makes it lose our variables, thus breaking the system in several places.
One example of this is a base ubuntu 24.04.01 which was upgraded to 24.04.02 and then it didnt boot anymore as the upgrade overwrote the os-release file to update the versions

This affects EFI systems only as we run a workaround for Ubuntu EFI and we need to identify the system as being ubuntu.

To Reproduce

Get a base ubuntu 24.04.01 kairos image, run apt-get upgrade and build/upgrade to that image. It wont boot anymore

Expected behavior

If vars are not available on os-release, we have a backup file to read them for.

Logs

Additional context

The idea here would be to have 2 files.

• /etc/os-release to keep backwards compatibility
• /etc/kairos/info.yaml with the info about the system, version, etc...

Then make everything that reads os-release to get info, read first /etc/kairos/info first, then fallback into os-release
And with time, deprecate writing to os-release as much as possible as its owned by the OS/Distro

We could even during the transition time, just on initramfs check if the info its on /etc/os-release and if its not, fill it with the info from the info file so we can keep the same behaviour as before, but not be vulnerable to changes from the OS. So have it filled on runtime, but actual info is in a different place.

Then we can deprecate havint he info in there if we want or keep it that way.

Reported on community slack, real case.

[Itxaka]

requires changes to:

• kairos: when building images we need to write to both files (🐛 Move kairos vars to their own file #2908)
• immucore: when reading from the os-release we need to first try from kairos-release (Not needed, not used there)
• agent: when reading from the os-release we need to first try from kairos-release (Move to use kairos-release kairos-agent#567)
• grub config: when reading from the os-release we need to first try from kairos-release (Use kairos-release instead of os-release packages#1082)
• any package that reads from the os-release needs to try first to read from kairos-release (Use kairos-release instead of os-release packages#1082)
• sdk (Move to use kairos-release instead of os-release kairos-sdk#506)
• enki (Move to use kairos-release enki#198)
• osbuilder (Move to use kairos-release osbuilder#184)

[Itxaka]

Ideally we would not need to to keep a lot of the fallback in place for the following.

• kairos: If we build with kairos-release then thats it, no need ot keep os-release as fallback as the images will have the stuff in kairos-release
• agent: only reset and install use them and those will be shipped in the new kairos version that only ship kairos-release, so we would not need to fallback

For this is necessary:

• grub config: this is needed as you can have an updated active but not passive/recovery so we still need it there
• static configs: Still needed due to reasons above, booting from an old recovery would not work as expected (its only a printed line that uses it, but still)
• enki+osbuilder: Needed because you can use an updated osbuilde/enki to build an older version

[Itxaka]

blocked until patch release for 3.2.x is done

[jimmykarily]

This one is full of os-release logic too: https://github.com/kairos-io/kairos-sdk/blob/main/versioneer/versioneer.go

[jimmykarily]

This one is full of os-release logic too: https://github.com/kairos-io/kairos-sdk/blob/main/versioneer/versioneer.go

I see we changed some things here but we may have to rename some functions to not imply /etc/os-release anymore.