Change WebSphere Liberty images from UBI 8 to 9

[leochr]

Existing UBI images for Liberty are based on UBI 8. Update the images to use UBI 9. But consider any breaking change/implication with moving the UBI version up.

Semeru images based on UBI 9 are already available in icr.io. Check up on IBM Java image.

[leochr]

UBI 8 will be in support at least until 2029 (according to the information in https://access.redhat.com/support/policy/updates/errata#RHEL8_Life_Cycle). Some OS CVEs are only fixed for UBI 9 and not UBI 8 (it's marked as 'Will not fix' in Red Hat's CVE bulletin). Given these, the plan is to change Liberty images from UBI 8 to UBI 9. To minimize disruption, this change will be done in a non-quarterly driver 23.0.0.10. At that time, images for 23.0.0.6 and 23.0.0.9 would still be supported and would remain with UBI 8. This will provide customers that need to stay on a supported Liberty quarterly release images that's based on UBI 8 until the release of 24.0.0.6 (8 months).

[tjwatson]

Given these, the plan is to change Liberty images from UBI 8 to UBI 9. To minimize disruption, this change will be done in a non-quarterly driver 23.0.0.10.

We need to add an issue to the Open-Liberty planning to support InstantOn with UBI 9 very soon then. We have not investigated UBI 9 for many months but last time we did there were some challenges that we needed to overcome.

[vijaysun-omr]

There may be additional challenges with respect to supporting InstantOn on Power and Z with UBI9. I think we need more time (at least for those platforms and perhaps even for X86) from an InstantOn perspective.