🌱 Skip machines with one WWN, if RAID is desired.

[guettli]

What this PR does / why we need it:

Skip machines with one WWN, if RAID is desired.

Fixes #1122

Special notes for your reviewer:

TODOs:

• squash commits
• include documentation
• add unit tests

[janiskemper]

Is this something that happens often?
This should be documented accordingly. Right now people probably try to do this and wonder why the host does not get chosen.

Should we also include a log or event for this?

[guettli]

Is this something that happens often? This should be documented accordingly. Right now people probably try to do this and wonder why the host does not get chosen.

Should we also include a log or event for this?

in 88bd718 i added a "reason", so that users understand why hosts were not picked.

[guettli]

@janiskemper please review

[janiskemper]

did you do more than fixing the test? If not, I'll approve

[guettli]

did you do more than fixing the test? If not, I'll approve

tiny changes got done:

I increased the log-level so that the message is actually visible:

s.scope.Info("No available host found. Requeuing.", "reason", reason)

if there is no available host, then the error message is more explicit now:

	if availableHosts == 0 {
		return nil, nil, fmt.Sprintf("No available host found. %d hosts exist.",
			len(hosts.Items)), nil
	}

solved