[OVN] Allow IP allocation with different segments for OVN service ports

OVN creates localport [1] for each network that has metadata
and allocate IP address from subnet within this network that has
DHCP enabled. The traffic from this port will never go outside
the chassis.

While using multiple segments with subnet linked to each segment
OVN needs to create an allocation of IP address for each of those
subnets [2] in order to generate data for OVN NBDB IPv4 DHCP Options.

The change [3] started to validate that condition, while multiple
IP addresses from different segments are tried to be allocated on
one port. We can skip this for OVN Metadata port, because there
is no reason to prevent those kind of allocation for OVN.

For stable branches we decide if a port is distributed or not
by looking for DEVICE_OWNER_DHCP device owner  and `ovn` device_id,
instead DEVICE_OWNER_DISTRIBUTED device owner.

Conflicts:
   neutron/db/ipam_backend_mixin.py
   neutron/tests/unit/db/test_ipam_pluggable_backend.py
   neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py

[1] http://www.openvswitch.org/support/dist-docs/ovn-architecture.7.html
[2] 5f42488a9a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_client.py (L2279)
[3] https://review.opendev.org/#/c/709444/

Change-Id: Ib51cde89ed873f48db4daebc27a0980da9cc0f19
Closes-Bug: 1871608
(cherry picked from commit 8d1512afb0)
This commit is contained in:
Maciej Józefczyk 2020-04-16 12:58:15 +00:00
parent f365093bad
commit 8f1912a1d1
7 changed files with 86 additions and 16 deletions

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@ -27,7 +27,10 @@ A routed provider network enables a single provider network to represent
multiple layer-2 networks (broadcast domains) or segments and enables the
operator to present one network to users. However, the particular IP
addresses available to an instance depend on the segment of the network
available on the particular compute node.
available on the particular compute node. Neutron port could be associated
with only one network segment, but there is an exception for OVN distributed
services like OVN Metadata.
Similar to conventional networking, layer-2 (switching) handles transit of
traffic between ports on the same segment and layer-3 (routing) handles

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@ -118,6 +118,9 @@ Routed provider networks offer performance at scale that is difficult to
achieve with a plain provider network at the expense of guaranteed layer-2
connectivity.
Neutron port could be associated with only one network segment,
but there is an exception for OVN distributed services like OVN Metadata.
See :ref:`config-routed-provider-networks` for more information.
.. _intro-os-networking-selfservice:

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@ -77,6 +77,11 @@ class IpamBackendMixin(db_base_plugin_common.DbBasePluginCommon):
raise exc.InvalidAllocationPool(pool=ip_pool)
return ip_range_pools
@staticmethod
def _is_distributed_service(port):
return (port.get('device_owner') == const.DEVICE_OWNER_DHCP and
port.get('device_id').startswith('ovn'))
def delete_subnet(self, context, subnet_id):
pass
@ -642,7 +647,8 @@ class IpamBackendMixin(db_base_plugin_common.DbBasePluginCommon):
return fixed_ip_list
def _ipam_get_subnets(self, context, network_id, host, service_type=None,
fixed_configured=False, fixed_ips=None):
fixed_configured=False, fixed_ips=None,
distributed_service=False):
"""Return eligible subnets
If no eligible subnets are found, determine why and potentially raise
@ -650,7 +656,7 @@ class IpamBackendMixin(db_base_plugin_common.DbBasePluginCommon):
"""
subnets = subnet_obj.Subnet.find_candidate_subnets(
context, network_id, host, service_type, fixed_configured,
fixed_ips)
fixed_ips, distributed_service=distributed_service)
if subnets:
subnet_dicts = [self._make_subnet_dict(subnet, context=context)
for subnet in subnets]
@ -712,7 +718,8 @@ class IpamBackendMixin(db_base_plugin_common.DbBasePluginCommon):
if old_ips and new_host_requested and not fixed_ips_requested:
valid_subnets = self._ipam_get_subnets(
context, old_port['network_id'], host,
service_type=old_port.get('device_owner'))
service_type=old_port.get('device_owner'),
distributed_service=self._is_distributed_service(old_port))
valid_subnet_ids = {s['id'] for s in valid_subnets}
for fixed_ip in old_ips:
if fixed_ip['subnet_id'] not in valid_subnet_ids:

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@ -231,12 +231,14 @@ class IpamPluggableBackend(ipam_backend_mixin.IpamBackendMixin):
p = port['port']
fixed_configured = p['fixed_ips'] is not constants.ATTR_NOT_SPECIFIED
fixed_ips = p['fixed_ips'] if fixed_configured else []
subnets = self._ipam_get_subnets(context,
network_id=p['network_id'],
host=p.get(portbindings.HOST_ID),
service_type=p.get('device_owner'),
fixed_configured=fixed_configured,
fixed_ips=fixed_ips)
subnets = self._ipam_get_subnets(
context,
network_id=p['network_id'],
host=p.get(portbindings.HOST_ID),
service_type=p.get('device_owner'),
fixed_configured=fixed_configured,
fixed_ips=fixed_ips,
distributed_service=self._is_distributed_service(p))
v4, v6_stateful, v6_stateless = self._classify_subnets(
context, subnets)
@ -348,7 +350,8 @@ class IpamPluggableBackend(ipam_backend_mixin.IpamBackendMixin):
subnets = self._ipam_get_subnets(
context, network_id=port['network_id'], host=host,
service_type=port.get('device_owner'), fixed_configured=True,
fixed_ips=changes.add + changes.original)
fixed_ips=changes.add + changes.original,
distributed_service=self._is_distributed_service(port))
except ipam_exc.DeferIpam:
subnets = []

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@ -298,7 +298,8 @@ class Subnet(base.NeutronDbObject):
@classmethod
def find_candidate_subnets(cls, context, network_id, host, service_type,
fixed_configured, fixed_ips):
fixed_configured, fixed_ips,
distributed_service=False):
"""Find canditate subnets for the network, host, and service_type"""
query = cls.query_subnets_on_network(context, network_id)
query = SubnetServiceType.query_filter_service_subnets(
@ -312,7 +313,8 @@ class Subnet(base.NeutronDbObject):
# on port update with binding:host_id set. Allocation _cannot_
# be deferred as requested fixed_ips would then be lost.
return cls._query_filter_by_fixed_ips_segment(
query, fixed_ips).all()
query, fixed_ips,
allow_multiple_segments=distributed_service).all()
# If the host isn't known, we can't allocate on a routed network.
# So, exclude any subnets attached to segments.
return cls._query_exclude_subnets_on_segments(query).all()
@ -334,7 +336,8 @@ class Subnet(base.NeutronDbObject):
return [subnet for subnet, _mapping in results]
@classmethod
def _query_filter_by_fixed_ips_segment(cls, query, fixed_ips):
def _query_filter_by_fixed_ips_segment(cls, query, fixed_ips,
allow_multiple_segments=False):
"""Excludes subnets not on the same segment as fixed_ips
:raises: FixedIpsSubnetsNotOnSameSegment
@ -367,9 +370,12 @@ class Subnet(base.NeutronDbObject):
if subnet and subnet.segment_id not in segment_ids:
segment_ids.append(subnet.segment_id)
if 1 < len(segment_ids):
if 1 < len(segment_ids) and not allow_multiple_segments:
raise segment_exc.FixedIpsSubnetsNotOnSameSegment()
if allow_multiple_segments:
return query
segment_id = None if not segment_ids else segment_ids[0]
return query.filter(cls.db_model.segment_id == segment_id)

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@ -86,6 +86,18 @@ class TestIpamBackendMixin(base.BaseTestCase):
self.mixin._get_subnet_object = mock.Mock(
side_effect=_get_subnet_object)
def test__is_distributed_service(self):
port = {'device_owner':
'%snova' % constants.DEVICE_OWNER_COMPUTE_PREFIX,
'device_id': uuidutils.generate_uuid()}
self.assertFalse(self.mixin._is_distributed_service(port))
port = {'device_owner': constants.DEVICE_OWNER_DHCP,
'device_id': uuidutils.generate_uuid()}
self.assertFalse(self.mixin._is_distributed_service(port))
port = {'device_owner': constants.DEVICE_OWNER_DHCP,
'device_id': 'ovnmeta-%s' % uuidutils.generate_uuid()}
self.assertTrue(self.mixin._is_distributed_service(port))
def _test_get_changed_ips_for_port(self, expected, original_ips,
new_ips, owner):
change = self.mixin._get_changed_ips_for_port(self.ctx,

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@ -690,12 +690,48 @@ class TestDbBasePluginIpam(test_db_base.NeutronDbPluginV2TestCase):
mocks['ipam']._ipam_get_subnets.assert_called_once_with(
context, network_id=port_dict['network_id'], fixed_configured=True,
fixed_ips=[ip_dict], host=None,
service_type=port_dict['device_owner'])
service_type=port_dict['device_owner'],
distributed_service=False)
# Validate port_dict is passed into address_factory
address_factory.get_request.assert_called_once_with(context,
port_dict,
ip_dict)
@mock.patch('neutron.ipam.driver.Pool')
def test_update_ips_for_port_ovn_distributed_svc(self, pool_mock):
address_factory = mock.Mock()
mocks = self._prepare_mocks_with_pool_mock(
pool_mock, address_factory=address_factory)
context = mock.Mock()
new_ips = mock.Mock()
original_ips = mock.Mock()
mac = mock.Mock()
ip_dict = {'ip_address': '192.1.1.10',
'subnet_id': uuidutils.generate_uuid()}
changes = ipam_pluggable_backend.IpamPluggableBackend.Changes(
add=[ip_dict], original=[], remove=[])
changes_mock = mock.Mock(return_value=changes)
fixed_ips_mock = mock.Mock(return_value=changes.add)
mocks['ipam'] = ipam_pluggable_backend.IpamPluggableBackend()
mocks['ipam']._get_changed_ips_for_port = changes_mock
mocks['ipam']._ipam_get_subnets = mock.Mock(return_value=[])
mocks['ipam']._test_fixed_ips_for_port = fixed_ips_mock
mocks['ipam']._update_ips_for_pd_subnet = mock.Mock(return_value=[])
port_dict = {
'device_owner': constants.DEVICE_OWNER_DHCP,
'device_id': 'ovnmeta-%s' % uuidutils.generate_uuid(),
'network_id': uuidutils.generate_uuid()}
mocks['ipam']._update_ips_for_port(context, port_dict, None,
original_ips, new_ips, mac)
mocks['ipam']._ipam_get_subnets.assert_called_once_with(
context, network_id=port_dict['network_id'], fixed_configured=True,
fixed_ips=[ip_dict], host=None,
service_type=port_dict['device_owner'],
distributed_service=True)
@mock.patch('neutron.ipam.driver.Pool')
def test_update_ips_for_port_passes_port_id_to_factory(self, pool_mock):
port_id = uuidutils.generate_uuid()