}
	var queryFn func(fqdn string, qtype dnsmessage.Type)
	var responseFn func(fqdn string, qtype dnsmessage.Type) result
	if conf.singleRequest {
		queryFn = func(fqdn string, qtype dnsmessage.Type) {}
		responseFn = func(fqdn string, qtype dnsmessage.Type) result {
			dnsWaitGroup.Add(1)
			defer dnsWaitGroup.Done()
			p, server, err := r.tryOneName(ctx, conf, fqdn, qtype)
			return result{p, server, err}
		}

}

func (s *serverImpl) Providers() []Provider {
	return append([]Provider{}, s.providers...)
}

func (s *serverImpl) templateArgs() map[string]any {
	fqdn := fmt.Sprintf("ext-authz.%s.svc.cluster.local", s.ns.Name())
	return map[string]any{
		"fqdn":     fqdn,
		"httpName": httpName,
		"grpcName": grpcName,
		"httpPort": httpPort,
		"grpcPort": grpcPort,
	}
}

func TestValidateFQDN(t *testing.T) {
	tests := []struct {
		fqdn  string
		valid bool
		name  string
	}{
		{
			fqdn:  strings.Repeat("x", 256),
			valid: false,
			name:  "long FQDN",
		},
		{
			fqdn:  "",
			valid: false,
			name:  "empty FQDN",
		},
		{
			fqdn:  "istio.io",
			valid: true,
			name:  "standard FQDN",
		},
		{
			fqdn:  "istio.io.",
			valid: true,
			name:  "unambiguous FQDN",

	}

	clusterConfigCmd.PersistentFlags().StringVarP(&outputFormat, "output", "o", summaryOutput, "Output format: one of json|yaml|short")
	clusterConfigCmd.PersistentFlags().StringVar(&fqdn, "fqdn", "", "Filter clusters by substring of Service FQDN field")
	clusterConfigCmd.PersistentFlags().StringVar(&direction, "direction", "", "Filter clusters by Direction field")

		host, port, err := net.SplitHostPort(name)
		hasPort := err == nil

		// attempt to expand shortname to FQDN
		requestedName := name
		if hasPort {
			requestedName = host
		}
		allNames := []string{requestedName}
		if fqdn := tryFindFQDN(requestedName, node); fqdn != "" {
			allNames = append(allNames, fqdn)
		}

		for _, name := range allNames {
			ln, ok := filter[name]
			if !ok {

	AddressTypeIPv4 = AddressType(v1.IPv4Protocol)

	// AddressTypeIPv6 represents an IPv6 Address.
	AddressTypeIPv6 = AddressType(v1.IPv6Protocol)

	// AddressTypeFQDN represents a FQDN.
	AddressTypeFQDN = AddressType("FQDN")
)

// Endpoint represents a single logical "backend" implementing a service.
type Endpoint struct {
	// addresses of this endpoint. The contents of this field are interpreted

			name:    "pure ip6 address",
		},
		{
			service: "istio-pilot.istio-system.svc.cluster.local",
			valid:   true,
			name:    "standard kubernetes FQDN",
		},
		{
			service: "istio-pilot.istio-system.svc.cluster.local:3000",
			valid:   false,
			name:    "standard kubernetes FQDN with port",
		},
		{
			service: "bar/istio.io",
			valid:   true,
			name:    "extension provider service with namespace",
		},
		{

		}
	}
	return nil
}

// ValidateFQDN checks a fully-qualified domain name
func ValidateFQDN(fqdn string) error {
	if err := CheckDNS1123Preconditions(fqdn); err != nil {
		return err
	}
	return ValidateDNS1123Labels(fqdn)
}

// ValidateProxyAddress checks that a network address is well-formed
func ValidateProxyAddress(hostAddr string) error {

  // Name represents the name for the service.
  // For Kubernetes, this is the Service name.
  string name = 1;
  // Namespace represents the namespace for the service.
  string namespace = 2;
  // Hostname represents the FQDN of the service.
  // For Kubernetes, this would be <name>.<namespace>.svc.<cluster domain>.
  // TODO: support this field
  string hostname = 3;
  // Address represents the addresses the service can be reached at.

		d := d
		if len(d) == 0 {
			continue
		}

		fqdn := d[0].Config().ClusterLocalFQDN()
		cases = append(cases, TrafficTestCase{
			name: d[0].Config().Service,
			// This creates a Gateway with a TCP listener that will accept TCP traffic from host
			// `fqdn` and forward that traffic back to `fqdn`, from srcPort to targetPort