def get_zone_name(domain, account_number):
    """Get the matching zone for the given domain"""
    zones = get_zones(account_number)
    zone_name = ""
    for z in zones:
        if domain.endswith(z):
            # Find the most specific zone possible for the domain
            # Ex: If fqdn is a.b.c.com, there is a zone for c.com,
            # and a zone for b.c.com, we want to use b.c.com.
            if z.count(".") > zone_name.count("."):
                zone_name = z
    if not zone_name:
        function = sys._getframe().f_code.co_name
        metrics.send(f"{function}.fail", "counter", 1)
        raise Exception(f"No UltraDNS zone found for domain: {domain}")
    return zone_name
Get the matching zone for the given domain
lemur/plugins/lemur_acme/ultradns.py