provider/aws.go
func isAWSAlias(ep *endpoint.Endpoint, addrs []*endpoint.Endpoint) string {
	if prop, exists := ep.GetProviderSpecificProperty("alias"); ep.RecordType == endpoint.RecordTypeCNAME && exists && prop.Value == "true" {
		for _, addr := range addrs {
			if addr.DNSName == ep.Targets[0] {
				if hostedZone := canonicalHostedZone(addr.Targets[0]); hostedZone != "" {
					return hostedZone
				}

			}
		}
	}
	return ""
}
func isAWSAlias(ep *endpoint.Endpoint, addrs []*endpoint.Endpoint) string {
	if prop, exists := ep.GetProviderSpecificProperty("alias"); ep.RecordType == endpoint.RecordTypeCNAME && exists && prop.Value == "true" {
		for _, addr := range addrs {
			if addr.DNSName == ep.Targets[0] {
				if hostedZone := canonicalHostedZone(addr.Targets[0]); hostedZone != "" {
					return hostedZone
				}

			}
		}
	}
	return ""
}
// isAWSAlias determines if a given hostname belongs to an AWS Alias record by doing an reverse lookup.