Fix user-list failed if host uses host_ip/netmask

According bug exception trace this problem cause by host name validate .
The origin code use netaddr.IPAddress to validate host name, it just fit ip address,
so the ip/netmask style do not match this rule.To solve this problem,
I changed this method to netaddr.IPNetwork, which support ip and
ip/netmask. Also provide a test case to validate the method.

Change-Id: I8dad9d1496d09372698821b832d1baa4f0c35a0d
Closes-Bug: #1673874

trove/common/db/mysql/models.py

@@ -145,8 +145,8 @@ class MySQLUser(models.DatastoreUser):
         if CONF.hostname_require_valid_ip:
             try:
                 # '%' works as a MySQL wildcard, but it is not a valid
-                # part of an IPAddress
-                netaddr.IPAddress(value.replace('%', '1'))
+                # part of an IPNetwork
+                netaddr.IPNetwork(value.replace('%', '1'))
             except (ValueError, netaddr.AddrFormatError):
                 return False
             else:

trove/tests/unittests/guestagent/test_mysql_manager.py

@@ -20,6 +20,7 @@ from mock import patch
 from proboscis.asserts import assert_equal
 from testtools.matchers import Is, Equals, Not
 
+from trove.common.db.mysql import models
 from trove.common.exception import InsufficientSpaceForReplica
 from trove.common.exception import ProcessExecutionError
 from trove.common import instance as rd_instance
@@ -103,6 +104,15 @@ class GuestAgentManagerTest(DatastoreManagerTest):
         dbaas.MySqlAppStatus.get.assert_any_call()
         mock_status.update.assert_any_call()
 
+    def _empty_user(self):
+        return models.MySQLUser(deserializing=True)
+
+    def test_valid_host_name(self):
+        test_host = "192.58.197.0/255.255.255.0"
+        user = self._empty_user()
+        user.host = test_host
+        self.assertEqual(test_host, user.host)
+
     @patch.object(dbaas.MySqlAdmin, 'create_database')
     def test_create_database(self, create_db_mock):
         self.manager.create_database(self.context, ['db1'])