feat: Support configuring ListenerClass preset (with sensible defaults)

[sbernauer]

Description

Part of stackabletech/issues#770

With recent changes from stackabletech/issues#770, stackablectl demo install on kind broke, as kind by default does not have a LoadBalancer installed.

We could try to document/automate/whatnot this, but I expect significant user problems with this. So instead we can make stackablectl a little bit more clever and detect kind and k3s and don't use LoadBalancers in that case.

stackablectl now tries the following order and simple passes the result to the listener-operator helm-chart:

1. Use --listener-class-preset flag
2. If not set determine Kubernetes environment (kind, k3, IONOS) by looking at nodes and use according defaults
3. If any error occurs, default to ephemeral-nodes

PS: Yes I know the OnceCell is not ideal, but I hope this is a temporary feature until #406 is implemented properly.

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

Author

• Changes are OpenShift compatible
• CRD changes approved
• Helm chart can be installed and deployed operator works
• Integration tests passed (for non trivial changes)

Reviewer

• Code contains useful comments
• (Integration-)Test cases added
• Documentation added or updated
• Changelog updated
• Cargo.toml only contains references to git tags (not specific commits or branches)

Acceptance

• Feature Tracker has been updated
• Proper release label has been added

[NickLarsenNZ]

Some recommended changes.

I will update the PR description.

I also think "preset" should be plural: "presets", but that's outside of the scope of this and would need to change in the chart.

[sbernauer]

I also think "preset" should be plural: "presets", but that's outside of the scope of this and would need to change in the chart.

Hmm, I think preset is technically more correct, as it's e.g. "stable-nodes".
Yes, that produces 1..n ListenerClasses, but it's still a single preset, isn't it?

[NickLarsenNZ]

I also think "preset" should be plural: "presets", but that's outside of the scope of this and would need to change in the chart.

Hmm, I think preset is technically more correct, as it's e.g. "stable-nodes". Yes, that produces 1..n ListenerClasses, but it's still a single preset, isn't it?

yeah I guess it can be interpreted both ways. I tend to think what it results in... It results in a number of preset ListenerClasses (which are the presets).

Anyway, keep as is because it is valid too.

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That said, the docs say "presets": https://docs.stackable.tech/home/nightly/listener-operator/listenerclass/#presets

[NickLarsenNZ]

LGTM