Adding Optional default dns values for native dhcp

When building the native dhcp server config we use the dns domain/nameservers
from the network/subnet objects.
If not defined, we use the global values in the nsxlib config.
Now adding optional default parameters to be used instead of global ones.
This will enable using different configuration per network availability zone.

Change-Id: I38b458e2c530f29a0e5518257ed3041d0610df25

vmware_nsxlib/tests/unit/v3/nsxlib_testcase.py

@@ -43,6 +43,9 @@ PLUGIN_SCOPE = "plugin scope"
 PLUGIN_TAG = "plugin tag"
 PLUGIN_VER = "plugin ver"
 
+DNS_NAMESERVERS = ['1.1.1.1']
+DNS_DOMAIN = 'openstacklocal'
+
 
 def _mock_nsxlib():
     def _return_id_key(*args, **kwargs):
@@ -107,7 +110,10 @@ def get_default_nsxlib_config():
         nsx_api_managers=[],
         plugin_scope=PLUGIN_SCOPE,
         plugin_tag=PLUGIN_TAG,
-        plugin_ver=PLUGIN_VER)
+        plugin_ver=PLUGIN_VER,
+        dns_nameservers=DNS_NAMESERVERS,
+        dns_domain=DNS_DOMAIN
+    )
 
 
 def get_nsxlib_config_with_client_cert():

vmware_nsxlib/tests/unit/v3/test_native_dhcp.py

@@ -0,0 +1,88 @@
+# Copyright (c) 2017 VMware, Inc.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from vmware_nsxlib.tests.unit.v3 import nsxlib_testcase
+from vmware_nsxlib.v3 import native_dhcp
+
+
+# TODO(asarfaty): Add more test cases here
+class TestNativeDhcp(nsxlib_testcase.NsxLibTestCase):
+    """Tests for vmware_nsxlib.v3.native_dhcp.NsxLibNativeDhcp."""
+
+    def setUp(self, *args, **kwargs):
+        super(TestNativeDhcp, self).setUp()
+        self.handler = native_dhcp.NsxLibNativeDhcp(
+            self.nsxlib.client,
+            nsxlib_testcase.get_default_nsxlib_config())
+        self.net_dns_domain = 'a.com'
+        self.subnet_dns_nameserver = '1.1.1.1'
+        self.default_dns_domain = 'b.com'
+        self.default_dns_nameserver = '2.2.2.2'
+
+    def _get_server_config(self, with_net_dns=True, with_default_dns=True):
+        net = {'name': 'dummy',
+               'id': 'dummy'}
+        subnet = {'dns_nameservers': None,
+                  'gateway_ip': '2.2.2.2',
+                  'cidr': '5.5.0.0/24',
+                  'host_routes': []}
+        port = {'fixed_ips': [{'ip_address': '5.5.0.1'}]}
+        tags = []
+        if with_net_dns:
+            net['dns_domain'] = {'dns_domain': self.net_dns_domain}
+            subnet['dns_nameservers'] = [self.subnet_dns_nameserver]
+        if with_default_dns:
+            result = self.handler.build_server_config(
+                net, subnet, port, tags,
+                default_dns_nameservers=[self.default_dns_nameserver],
+                default_dns_domain=self.default_dns_domain)
+        else:
+            result = self.handler.build_server_config(net, subnet, port, tags)
+        return result
+
+    def test_build_server_config_dns_from_net_no_defaults(self):
+        # Verify that net/subnet dns params are used if exist
+        result = self._get_server_config(with_net_dns=True,
+                                         with_default_dns=False)
+        self.assertEqual(self.net_dns_domain, result['domain_name'])
+        self.assertEqual([self.subnet_dns_nameserver],
+                         result['dns_nameservers'])
+
+    def test_build_server_config_dns_from_net_with_defaults(self):
+        # Verify that net/subnet dns params are used if exist, even if there
+        # are defaults
+        result = self._get_server_config(with_net_dns=True,
+                                         with_default_dns=True)
+        self.assertEqual(self.net_dns_domain, result['domain_name'])
+        self.assertEqual([self.subnet_dns_nameserver],
+                         result['dns_nameservers'])
+
+    def test_build_server_config_dns_from_defaults(self):
+        # Verify that default dns params are used if net/subnet dns params
+        # are missing
+        result = self._get_server_config(with_net_dns=False,
+                                         with_default_dns=True)
+        self.assertEqual(self.default_dns_domain, result['domain_name'])
+        self.assertEqual([self.default_dns_nameserver],
+                         result['dns_nameservers'])
+
+    def test_build_server_config_dns_from_config(self):
+        # Verify that config dns params are used if net/subnet and default
+        # dns params are missing
+        result = self._get_server_config(with_net_dns=False,
+                                         with_default_dns=False)
+        self.assertEqual(nsxlib_testcase.DNS_DOMAIN, result['domain_name'])
+        self.assertEqual(nsxlib_testcase.DNS_NAMESERVERS,
+                         result['dns_nameservers'])

vmware_nsxlib/v3/native_dhcp.py

@@ -22,13 +22,19 @@ from vmware_nsxlib.v3 import utils
 
 class NsxLibNativeDhcp(utils.NsxLibApiBase):
 
-    def build_server_config(self, network, subnet, port, tags):
+    def build_server_config(self, network, subnet, port, tags,
+                            default_dns_nameservers=None,
+                            default_dns_domain=None):
         # Prepare the configuration for a new logical DHCP server.
         server_ip = "%s/%u" % (port['fixed_ips'][0]['ip_address'],
                                netaddr.IPNetwork(subnet['cidr']).prefixlen)
         dns_nameservers = subnet['dns_nameservers']
         if not dns_nameservers or not validators.is_attr_set(dns_nameservers):
-            dns_nameservers = self.nsxlib_config.dns_nameservers
+            # use the default one , or the globally configured one
+            if default_dns_nameservers is not None:
+                dns_nameservers = default_dns_nameservers
+            else:
+                dns_nameservers = self.nsxlib_config.dns_nameservers
         gateway_ip = subnet['gateway_ip']
         if not validators.is_attr_set(gateway_ip):
             gateway_ip = None
@@ -55,8 +61,14 @@ class NsxLibNativeDhcp(utils.NsxLibApiBase):
         name = utils.get_name_and_uuid(network['name'] or 'dhcpserver',
                                        network['id'])
         dns_domain = network.get('dns_domain')
-        domain_name = dns_domain['dns_domain'] if dns_domain else (
-            self.nsxlib_config.dns_domain)
+        if dns_domain:
+            domain_name = dns_domain['dns_domain']
+        else:
+            # use the default one , or the globally configured one
+            if default_dns_domain is not None:
+                domain_name = default_dns_domain
+            else:
+                domain_name = self.nsxlib_config.dns_domain
 
         return {'name': name,
                 'server_ip': server_ip,