Upgrade distribution versions

[Bischoff]

DRAFT

Support recent Linux distributions, deprecate old distributions

• Add RHEL 9.x, Ubuntu 24.04 and SLES 16.x
• Remove RHEL 6.x, Ubuntu 16.04 and SLES 11.x

Technical details:

• all recent distributions use /etc/os-release, no need to consider anymore /etc/redhat-release, /etc/SuSE-release, nor /etc/system-release
• network configuration:
  • RHEL 7, RHEL 8, SLES 12 and SLES 15 use ifcfg scripts
  • RHEL 9 and SLES 16 use NetworkManager (RHEL 9 still supports ifcfg files, but with lower priority)
  • CoreOS 4 uses fixed_ip_param
  • Ubuntu 20.04, 22.04, and 24.04 use NetPlan
• inheritance tree:

  object
    |
    +-- LinuxDist
          |
          +-- rhel
          |     |
          |     +-- rhel7
          |     |     |
          |     |     +-- rhel8
          |     |
          |     +-- rhel9 (used to inherit rhel8)
          |             |
          |             +- rhel10 (used to inherit rhel8)
          |
          +-- rhcos
          |     |
          |     +-- rhcos4
          |
          +-- sles
          |     |
          |     +-- sles12
          |     |     |
          |     |     +-- sles15
          |     |
          |     +-- sles16 (new)
          |
          +-- ubuntu
                |
                +-- ubuntu20
                      |
                      +-- ubuntu22
                      |
                      +-- ubuntu24
                      |
                      +-- ubuntu25