// Conveniently, exactly the format that ParseSelector takes.
func (ls Set) String() string {
	selector := make([]string, 0, len(ls))
	for key, value := range ls {
		selector = append(selector, key+"="+value)
	}
	// Sort for determinism.
	sort.StringSlice(selector).Sort()
	return strings.Join(selector, ",")
}

// Has returns whether the provided label exists in the map.
func (ls Set) Has(label string) bool {

		informers.WithNamespace(namespace),
		informers.WithTweakListOptions(func(listOptions *metav1.ListOptions) {
			listOptions.LabelSelector = labels.Set(map[string]string{labelKey: "true"}).AsSelector().String()
		})).
		Core().V1().ConfigMaps()
	c.cmInformer = i.Informer()
	c.cmHandle, _ = c.cmInformer.AddEventHandler(&DistroReportHandler{dc: c})

	return c
}

			{"metadata.name": "foo"},
		},
		false: {
			{"foo": "bar"},
		},
	}

	for expectedResult, fieldSet := range testFieldMap {
		for _, field := range fieldSet {
			m := MatchNode(labels.Everything(), field.AsSelector())
			_, matchesSingle := m.MatchesSingle()
			if e, a := expectedResult, matchesSingle; e != a {
				t.Errorf("%+v: expected %v, got %v", fieldSet, e, a)
			}
		}
	}
}

	// Using an index for selectoes is problematic because selector != label
	// We can match a label to a selector, but we can't generate a selector from a label.
	c.ForEach(gvk.Telemetry, func(rs *resource.Instance) bool {
		s := rs.Message.(*v1alpha1.Telemetry)

		// For this analysis, ignore Telemetries with no selectors specified at all.
		if s.Selector == nil || len(s.GetSelector().MatchLabels) == 0 {
			return true
		}

	"istio.io/istio/pkg/config/analysis/msg"
	"istio.io/istio/pkg/config/resource"
	"istio.io/istio/pkg/config/schema/gvk"
)

// SelectorAnalyzer validates, per namespace, that:
// * sidecar resources that define a workload selector match at least one pod
// * there aren't multiple sidecar resources that select overlapping pods
type SelectorAnalyzer struct{}

var _ analysis.Analyzer = &SelectorAnalyzer{}

// Metadata implements Analyzer

)

// ByServiceSelector returns a predicate that matches workload instances
// of a given service.
func ByServiceSelector(namespace string, selector labels.Instance) func(*model.WorkloadInstance) bool {
	return func(wi *model.WorkloadInstance) bool {
		return wi.Namespace == namespace && selector.Match(wi.Endpoint.Labels)
	}
}

// FindAllInIndex returns a list of workload instances in the index
// that match given predicate.
//

kind: Telemetry
metadata:
  name: dupe-1
  namespace: default
spec:
  selector:
    matchLabels:
      app: reviews # Multiple telemetries have the same selector, should generate errors for both
  metrics:
    - providers:
        - name: prometheus
      overrides:
        - match:
            metric: ALL_METRICS
          disabled: false
---
apiVersion: telemetry.istio.io/v1alpha1
kind: Telemetry
metadata:

spec:
  containers:
  - image: proxyv2:1.3.1
    name: istio-proxy
---
# only selector is set, should be ineffective
apiVersion: security.istio.io/v1
kind: RequestAuthentication
metadata:
  namespace: default
  name: ra-ineffective
spec:
  selector:
    matchLabels:
      gateway.networking.k8s.io/gateway-name: bookinfo-gateway
---
# only selector is set, should be ineffective
apiVersion: security.istio.io/v1

kind: Telemetry
metadata:
  name: no-selector # Since this is the only Telemetry in the namespace without a selector, no conflict
  namespace: ns1
spec:
  metrics:
  - providers:
    - name: prometheus
    overrides:
    - match:
        metric: ALL_METRICS
      disabled: false
---
apiVersion: telemetry.istio.io/v1alpha1
kind: Telemetry
metadata:
  name: has-selector
  namespace: ns1
spec:

kind: Sidecar
metadata:
  name: no-selector # Since this is the only Sidecar in the namespace without a workload selector, no conflict
  namespace: ns1
spec:
  egress:
  - hosts:
    - "./*"
---
apiVersion: networking.istio.io/v1alpha3
kind: Sidecar
metadata:
  name: has-selector
  namespace: ns1
spec:
  workloadSelector: # Since this has a workload selector, it shouldn't conflict with the other Sidecar in the namespace