What is the StateSet behavior on an array of a CustomResourceStateMetrics?

[richard-zang]

I have an array of zero or more objects and I want to create a metric where each state has a value of zero or one.
What is the behavior if I try to create a StateSet metric on an array of values?

I see that targeting an array for Gauges will create a metric for each element in the array but I don't see anything that indicates if this works for StateSets.

kube-state-metrics/pkg/customresourcestate/config_metrics_types.go

Line 37 in 0cbabf9

// MetricGauge targets a Path that may be a single value, array, or object. Arrays and objects will generate a metric per element.

For example, say I had the following CR:

...
status:
  foostates:
    - foostate: A
      misc: 1
    - foostate: B
      misc: 2
...

and the following config:

...
type: StateSet
stateSet:
  labelName: mystate
  path: [status, foostates, foostate]
  list: [A, B, C]
...

Would I get something like the following?
my_metric{mystate="A"} 1
my_metric{mystate="B"} 1
my_metric{mystate="C"} 0

[fpetkovski]

This is the code which generates values for state sets:

kube-state-metrics/pkg/customresourcestate/registry_factory.go

Lines 312 to 352 in 0cbabf9

	type compiledStateSet struct {
	compiledCommon
	ValueFrom valuePath
	List []string
	LabelName string
	}
	func (c *compiledStateSet) Values(v interface{}) (result []eachValue, errs []error) {
	if vs, isArray := v.([]interface{}); isArray {
	for _, obj := range vs {
	ev, err := c.values(obj)
	if len(err) > 0 {
	errs = append(errs, err...)
	continue
	}
	result = append(result, ev...)
	}
	return
	}
	return c.values(v)
	}
	func (c *compiledStateSet) values(v interface{}) (result []eachValue, errs []error) {
	comparable := c.ValueFrom.Get(v)
	value, ok := comparable.(string)
	if !ok {
	return []eachValue{}, []error{fmt.Errorf("%s: expected value for path to be string, got %T", c.path, comparable)}
	}
	for _, entry := range c.List {
	ev := eachValue{Value: 0, Labels: map[string]string{}}
	if value == entry {
	ev.Value = 1
	}
	ev.Labels[c.LabelName] = entry
	addPathLabels(v, c.labelFromPath, ev.Labels)
	result = append(result, ev)
	}
	return
	}

I assume it will be similar to what you suggested, but feel free to test it out on a real case.