--- /dev/null
+Keep DNS Nameserver Order Consistency In Neutron
+================================================
+
+In Neutron subnets, DNS nameservers are given priority when created or updated.
+This means if you create a subnet with multiple DNS servers, the order will
+be retained and guests will receive the DNS servers in the order you
+created them in when the subnet was created. The same thing applies for update
+operations on subnets to add, remove, or update DNS servers.
+
+Get Subnet Details Info
+-----------------------
+::
+
+ changzhi@stack:~/devstack$ neutron subnet-list
+ +--------------------------------------+------+-------------+--------------------------------------------+
+ | id | name | cidr | allocation_pools |
+ +--------------------------------------+------+-------------+--------------------------------------------+
+ | 1a2d261b-b233-3ab9-902e-88576a82afa6 | | 10.0.0.0/24 | {"start": "10.0.0.2", "end": "10.0.0.254"} |
+ +--------------------------------------+------+-------------+--------------------------------------------+
+
+ changzhi@stack:~/devstack$ neutron subnet-show 1a2d261b-b233-3ab9-902e-88576a82afa6
+ +------------------+--------------------------------------------+
+ | Field | Value |
+ +------------------+--------------------------------------------+
+ | allocation_pools | {"start": "10.0.0.2", "end": "10.0.0.254"} |
+ | cidr | 10.0.0.0/24 |
+ | dns_nameservers | 1.1.1.1 |
+ | | 2.2.2.2 |
+ | | 3.3.3.3 |
+ | enable_dhcp | True |
+ | gateway_ip | 10.0.0.1 |
+ | host_routes | |
+ | id | 1a2d26fb-b733-4ab3-992e-88554a87afa6 |
+ | ip_version | 4 |
+ | name | |
+ | network_id | a404518c-800d-2353-9193-57dbb42ac5ee |
+ | tenant_id | 3868290ab10f417390acbb754160dbb2 |
+ +------------------+--------------------------------------------+
+
+Update Subnet DNS Nameservers
+-----------------------------
+::
+
+ neutron subnet-update 1a2d261b-b233-3ab9-902e-88576a82afa6 \
+ --dns_nameservers list=true 3.3.3.3 2.2.2.2 1.1.1.1
+
+ changzhi@stack:~/devstack$ neutron subnet-show 1a2d261b-b233-3ab9-902e-88576a82afa6
+ +------------------+--------------------------------------------+
+ | Field | Value |
+ +------------------+--------------------------------------------+
+ | allocation_pools | {"start": "10.0.0.2", "end": "10.0.0.254"} |
+ | cidr | 10.0.0.0/24 |
+ | dns_nameservers | 3.3.3.3 |
+ | | 2.2.2.2 |
+ | | 1.1.1.1 |
+ | enable_dhcp | True |
+ | gateway_ip | 10.0.0.1 |
+ | host_routes | |
+ | id | 1a2d26fb-b733-4ab3-992e-88554a87afa6 |
+ | ip_version | 4 |
+ | name | |
+ | network_id | a404518c-800d-2353-9193-57dbb42ac5ee |
+ | tenant_id | 3868290ab10f417390acbb754160dbb2 |
+ +------------------+--------------------------------------------+
+
+As shown in above output, the order of the DNS nameservers has been updated.
+New virtual machines deployed to this subnet will receive the DNS nameservers
+in this new priority order. Existing virtual machines that have already been
+deployed will not be immediately affected by changing the DNS nameserver order
+on the neutron subnet. Virtual machines that are configured to get their IP
+address via DHCP will detect the DNS nameserver order change
+when their DHCP lease expires or when the virtual machine is restarted.
+Existing virtual machines configured with a static IP address will never
+detect the updated DNS nameserver order.
advanced_services
oslo-incubator
callbacks
+ dns_order
Testing
-------
def _get_dns_by_subnet(self, context, subnet_id):
dns_qry = context.session.query(models_v2.DNSNameServer)
- return dns_qry.filter_by(subnet_id=subnet_id).all()
+ return dns_qry.filter_by(subnet_id=subnet_id).order_by(
+ models_v2.DNSNameServer.order).all()
def _get_route_by_subnet(self, context, subnet_id):
route_qry = context.session.query(models_v2.SubnetRoute)
def _update_subnet_dns_nameservers(self, context, id, s):
old_dns_list = self._get_dns_by_subnet(context, id)
- new_dns_addr_set = set(s["dns_nameservers"])
- old_dns_addr_set = set([dns['address']
- for dns in old_dns_list])
-
- new_dns = list(new_dns_addr_set)
- for dns_addr in old_dns_addr_set - new_dns_addr_set:
- for dns in old_dns_list:
- if dns['address'] == dns_addr:
- context.session.delete(dns)
- for dns_addr in new_dns_addr_set - old_dns_addr_set:
+ new_dns_addr_list = s["dns_nameservers"]
+
+ # NOTE(changzhi) delete all dns nameservers from db
+ # when update subnet's DNS nameservers. And store new
+ # nameservers with order one by one.
+ for dns in old_dns_list:
+ context.session.delete(dns)
+
+ for order, server in enumerate(new_dns_addr_list):
dns = models_v2.DNSNameServer(
- address=dns_addr,
+ address=server,
+ order=order,
subnet_id=id)
context.session.add(dns)
del s["dns_nameservers"]
- return new_dns
+ return new_dns_addr_list
def _update_subnet_allocation_pools(self, context, subnet_id, s):
context.session.query(models_v2.IPAllocationPool).filter_by(
subnet = models_v2.Subnet(**subnet_args)
context.session.add(subnet)
+ # NOTE(changzhi) Store DNS nameservers with order into DB one
+ # by one when create subnet with DNS nameservers
if attributes.is_attr_set(dns_nameservers):
- for addr in dns_nameservers:
- ns = models_v2.DNSNameServer(address=addr,
- subnet_id=subnet.id)
- context.session.add(ns)
+ for order, server in enumerate(dns_nameservers):
+ dns = models_v2.DNSNameServer(
+ address=server,
+ order=order,
+ subnet_id=subnet.id)
+ context.session.add(dns)
if attributes.is_attr_set(host_routes):
for rt in host_routes:
-2a16083502f3
+1c844d1677f7
45f955889773
kilo
--- /dev/null
+# Copyright 2015 OpenStack Foundation
+#
+# 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.
+#
+
+"""add order to dnsnameservers
+
+Revision ID: 1c844d1677f7
+Revises: 2a16083502f3
+Create Date: 2015-07-21 22:59:03.383850
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '1c844d1677f7'
+down_revision = '2a16083502f3'
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+ op.add_column('dnsnameservers',
+ sa.Column('order', sa.Integer(),
+ server_default='0', nullable=False))
sa.ForeignKey('subnets.id',
ondelete="CASCADE"),
primary_key=True)
+ order = sa.Column(sa.Integer, nullable=False, server_default='0')
class Subnet(model_base.BASEV2, HasId, HasTenant):
dns_nameservers = orm.relationship(DNSNameServer,
backref='subnet',
cascade='all, delete, delete-orphan',
+ order_by=DNSNameServer.order,
lazy='joined')
routes = orm.relationship(SubnetRoute,
backref='subnet',
host_routes = []
+class FakeV4SubnetAgentWithManyDnsProvided(object):
+ id = 'dddddddd-dddd-dddd-dddd-dddddddddddd'
+ ip_version = 4
+ cidr = '192.168.0.0/24'
+ gateway_ip = '192.168.0.1'
+ enable_dhcp = True
+ dns_nameservers = ['2.2.2.2', '9.9.9.9', '1.1.1.1',
+ '3.3.3.3']
+ host_routes = []
+
+
class FakeV4MultipleAgentsWithoutDnsProvided(object):
id = 'ffffffff-ffff-ffff-ffff-ffffffffffff'
subnets = [FakeV4SubnetMultipleAgentsWithoutDnsProvided()]
namespace = 'qdhcp-ns'
+class FakeV4AgentWithManyDnsProvided(object):
+ id = 'ffffffff-ffff-ffff-ffff-ffffffffffff'
+ subnets = [FakeV4SubnetAgentWithManyDnsProvided()]
+ ports = [FakePort1(), FakePort2(), FakePort3(), FakeRouterPort(),
+ FakePortMultipleAgents1()]
+ namespace = 'qdhcp-ns'
+
+
class FakeV4SubnetMultipleAgentsWithDnsProvided(object):
id = 'dddddddd-dddd-dddd-dddd-dddddddddddd'
ip_version = 4
self._test_output_opts_file(expected,
FakeV4MultipleAgentsWithoutDnsProvided())
+ def test_output_opts_file_agent_with_many_dns_provided(self):
+ expected = ('tag:tag0,'
+ 'option:dns-server,2.2.2.2,9.9.9.9,1.1.1.1,3.3.3.3\n'
+ 'tag:tag0,option:classless-static-route,'
+ '169.254.169.254/32,192.168.0.1,0.0.0.0/0,192.168.0.1\n'
+ 'tag:tag0,249,169.254.169.254/32,192.168.0.1,0.0.0.0/0,'
+ '192.168.0.1\n'
+ 'tag:tag0,option:router,192.168.0.1').lstrip()
+
+ self._test_output_opts_file(expected,
+ FakeV4AgentWithManyDnsProvided())
+
def test_output_opts_file_multiple_agents_with_dns_provided(self):
expected = ('tag:tag0,option:dns-server,8.8.8.8\n'
'tag:tag0,option:classless-static-route,'
res = self.deserialize(self.fmt, req.get_response(self.api))
self.assertEqual(sorted(res['subnet']['host_routes']),
sorted(host_routes))
- self.assertEqual(sorted(res['subnet']['dns_nameservers']),
- sorted(dns_nameservers))
+ self.assertEqual(res['subnet']['dns_nameservers'],
+ dns_nameservers)
def test_update_subnet_shared_returns_400(self):
with self.network(shared=True) as network:
self.assertEqual(res['subnet']['dns_nameservers'],
data['subnet']['dns_nameservers'])
+ def test_subnet_lifecycle_dns_retains_order(self):
+ cfg.CONF.set_override('max_dns_nameservers', 3)
+ with self.subnet(dns_nameservers=['1.1.1.1', '2.2.2.2',
+ '3.3.3.3']) as subnet:
+ subnets = self._show('subnets', subnet['subnet']['id'],
+ expected_code=webob.exc.HTTPOk.code)
+ self.assertEqual(['1.1.1.1', '2.2.2.2', '3.3.3.3'],
+ subnets['subnet']['dns_nameservers'])
+ data = {'subnet': {'dns_nameservers': ['2.2.2.2', '3.3.3.3',
+ '1.1.1.1']}}
+ req = self.new_update_request('subnets',
+ data,
+ subnet['subnet']['id'])
+ res = self.deserialize(self.fmt, req.get_response(self.api))
+ self.assertEqual(data['subnet']['dns_nameservers'],
+ res['subnet']['dns_nameservers'])
+ subnets = self._show('subnets', subnet['subnet']['id'],
+ expected_code=webob.exc.HTTPOk.code)
+ self.assertEqual(data['subnet']['dns_nameservers'],
+ subnets['subnet']['dns_nameservers'])
+
def test_update_subnet_dns_to_None(self):
with self.subnet(dns_nameservers=['11.0.0.1']) as subnet:
data = {'subnet': {'dns_nameservers': None}}
Code Review / openstack-build / neutron-build.git / commitdiff