Revert "DNS Locations: do not generate location records for unused locations"

This reverts commit bbf8227e3f.

After deeper investigation, we found out that empty locations are needed
for clients, because clients may have cached records for longer time for
that particular location. Only way how to remove location is to remove
it using location-del

https://fedorahosted.org/freeipa/ticket/2008

Reviewed-By: Petr Spacek <pspacek@redhat.com>

ipaserver/dns_data_management.py

@@ -68,7 +68,6 @@ class IPASystemRecords(object):
         self.api_instance = api_instance
         self.domain_abs = DNSName(self.api_instance.env.domain).make_absolute()
         self.servers_data = {}
-        self.used_locations = set()
         self.__init_data()
 
     def reload_data(self):
@@ -92,7 +91,6 @@ class IPASystemRecords(object):
 
     def __init_data(self):
         self.servers_data = {}
-        self.used_locations = set()
 
         servers_result = self.api_instance.Command.server_find(
             pkey_only=True)['result']
@@ -104,8 +102,6 @@ class IPASystemRecords(object):
                 'location': location,
                 'roles': roles,
             }
-            if location:
-                self.used_locations.add(location)
 
     def __add_srv_records(
         self, zone_obj, hostname, rname_port_map,
@@ -353,12 +349,13 @@ class IPASystemRecords(object):
                 pkey_only=True)['result']
             servers = [s['cn'][0] for s in servers_result]
 
-        # generate only records for used location, records for unassigned
-        # locations are useless
+        locations_result = self.api_instance.Command.location_find()['result']
+        locations = [l['idnsname'][0] for l in locations_result]
+
         for server in servers:
             self._get_location_dns_records_for_server(
                 zone_obj, server,
-                self.used_locations, roles=roles,
+                locations, roles=roles,
                 include_master_role=include_master_role)
         return zone_obj