Relying on undefined behavior - parsing kubernetes resource names

[thockin]

There appears to be a bug at https://github.com/weaveworks/wksctl/blob/master/pkg/cluster/machine/machines_manifest_test.go#L46

The random suffix of a pod or other resource is not guaranteed to be 5 characters, nor is the characterset defined. Those are implementation details, not to be depended on. This is brittle and could change at any time.

You should be using labels to extract metadata, not parsing the name. That's literally why they exist.