bootc version support policy

[cheesesashimi]

Because bootc is under active development and because new features are being added all the time, we should ensure that bootc-operator can work against a range of bootc versions and that it can handle discrepancies between different bootc versions. To do that, it might be useful to set a minimum supported version number for each bootc-operator release.

For example, bootc-operator could require a minimum version of, say, v1.15.2. And within CI, we ensure that our CI tests run against a node which runs this older version as well as the latest bootc version available.

It could also be useful for the bootc-operator to report what bootc version is running on each of the nodes within the cluster via the BootcNodeStatus field. Perhaps bootc itself could be modified to surface that information as part of the bootc status --json output instead of requiring that one run bootc --version.

[alicefr]

Many thanks @cheesesashimi for raising this. Do you mind opening an issue in bootc for reporting the version?

As far as it regards the test matrix is a valid point. However, we are already testing a lot of variants among 3 kubernetes versions and composefs. If we add different bootc versions on top, the number of the lanes will explode.
Which variation would you like to test?
I would say we should stick the main kubernetes version (right now 1.35), bootc from copper for ostree and composefs, and maybe the bootc version shipped by fedora. Or did you have something else in mind?