[installer-tests] Test K3s with different Ubuntu versions

[kylos101]

Is your feature request related to a problem? Please describe

Test automation uses a specific Ubuntu image.

Describe the behaviour you'd like

It would be nice to test many versions of Ubuntu.

Why? We currently support 18.04, and 20.04, and are running 22.04 on the saas.

What if 18 or 20 break? We won't know (easily) unless a self-hosted customer tells us, because the saas is on 22.

Ideally we'd be able to include other variables too, for more complex permutations, like Kubernetes and containerd versions. But I think we need to be careful in how many permutations we take one...it'll quickly grow out of control.

Describe alternatives you've considered

Right now the version is stored in a file, and triggered via werft. Perhaps we can provide for the ability to override some values at runtime?

Additional context

The product compatibility matrix [internal] has many combinations. We should pick the highest risk variables and invest in related test automation.

[mrsimonemms]

One thing to note is that it seems that Ubuntu 22.04 has changed their SSH authentication process. It works fine if you're using normal ssh in a terminal, but it seems to have broken how applications such as k3sup use it - see this issue for instance

[lucasvaltl]

This is related to #7316 and #10620 and will likely be covered in the latter.

[lucasvaltl]

@nandajavarma how does this ticket fit into your next steps for automated testing? Would you mind moving this to the relevant state: backlog if we are not going to work on it soon, and scheduled if we are going to work on it soon.

[nandajavarma]

@lucasvaltl Thanks for the ping. I am planning to make this part of the epic that covers self-signed certs. So hopefully in 2 weeks I will get started on this. Will move to scheduled

[nandajavarma]

Closing this in favor of #11272