openstack/neutron-fwaas
Code Issues Proposed changes

Round-robin SVI switch selection fails on Cisco Nexus plugin

Browse Source 
Fixes bug 1250969

This fix addresses improper behavior with the Cisco Nexus plugin's
selection of Nexus switch on which to place a Switch Virtual Interface
(SVI) when round-robin switch placement is enabled.

The expected behavior when round-robin SVI switch selection is configured
via the cisco_plugins.ini file, i.e.:
    [cisco]
    nexus_l3_enable = True
    svi_round_robin = True
is that when a virtual router interface is created, the Nexus plugin should
select the Nexus switch with the least number of SVI interfaces configured
for creating the new SVI. The current selection is based on the first
entry in a dictionary, and is therefore indeterminate.

Similarly, this fix also addresses incorrect behavior when round-robin
selection is disabled. In this case, the desired behavior is that
the plugin should select the first switch which appears in the Nexus
switch configuration. Instead, the current selection is also based on the
first entry in a dictionary, and is likewise indeterminate.

Change-Id: I548c1efaa8b54695246251b6823ab59e077836fe
This commit is contained in:
Dane LeBlanc 2013-11-13 23:10:21 -05:00
parent 0e2198ef75
commit 6b21cd29be
5 changed files with 77 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
neutron/plugins/cisco/common/config.py
View File

@ -106,6 +106,13 @@ CISCO_PLUGINS = cfg.CONF.CISCO_PLUGINS
#
device_dictionary = {}
#
# first_device_ip - IP address of first switch discovered in config
#
# Used for SVI placement when round-robin placement is disabled
#
first_device_ip = None
class CiscoConfigOptions():
"""Cisco Configuration Options Class."""
@ -119,17 +126,22 @@ class CiscoConfigOptions():
device supported sections. Ex. NEXUS_SWITCH, N1KV.
"""
global first_device_ip
multi_parser = cfg.MultiConfigParser()
read_ok = multi_parser.read(CONF.config_file)
if len(read_ok) != len(CONF.config_file):
raise cfg.Error(_("Some config files were not parsed properly"))
first_device_ip = None
for parsed_file in multi_parser.parsed:
for parsed_item in parsed_file.keys():
dev_id, sep, dev_ip = parsed_item.partition(':')
if dev_id.lower() in ['nexus_switch', 'n1kv']:
for dev_key, value in parsed_file[parsed_item].items():
if dev_ip and not first_device_ip:
first_device_ip = dev_ip
device_dictionary[dev_id, dev_ip, dev_key] = value[0]

7
neutron/plugins/cisco/nexus/cisco_nexus_plugin_v2.py
View File

@ -228,15 +228,14 @@ class NexusPlugin(L2DevicePluginBase):
switch_dict[switch_ip] += 1
# Search for the lowest value in the dict
if switch_dict:
switch_ip = min(switch_dict.items(), key=switch_dict.get)
return switch_ip[0]
switch_ip = min(switch_dict, key=switch_dict.get)
return switch_ip
except cisco_exc.NexusPortBindingNotFound:
pass
LOG.debug(_("No round robin or zero weights, using first switch"))
# Return the first switch in the config
for switch_ip, attr in nexus_switches:
return switch_ip
return conf.first_device_ip
def delete_network(self, tenant_id, net_id, **kwargs):
"""Delete network.

6
neutron/tests/unit/cisco/test_network_plugin.py
View File

@ -127,6 +127,12 @@ class CiscoNetworkPluginV2TestCase(test_db_plugin.NeutronDbPluginV2TestCase):
super(CiscoNetworkPluginV2TestCase, self).setUp(CORE_PLUGIN)
self.port_create_status = 'DOWN'
# Set Cisco config module's first configured Nexus IP address.
# Used for SVI placement when round-robin placement is disabled.
mock.patch.object(cisco_config, 'first_device_ip',
new=NEXUS_IP_ADDR).start()
self.addCleanup(mock.patch.stopall)
def _get_plugin_ref(self):
plugin_obj = NeutronManager.get_plugin()
if getattr(plugin_obj, "_master"):

49
neutron/tests/unit/cisco/test_nexus_db.py
View File

@ -14,11 +14,14 @@
# under the License.
import collections
import mock
import testtools
from neutron.db import api as db
from neutron.plugins.cisco.common import cisco_exceptions as c_exc
from neutron.plugins.cisco.common import config
from neutron.plugins.cisco.db import nexus_db_v2 as nxdb
from neutron.plugins.cisco.nexus import cisco_nexus_plugin_v2
from neutron.tests import base
@ -166,6 +169,52 @@ class CiscoNexusDbTest(base.BaseTestCase):
npb_svi = nxdb.get_nexussvi_bindings()
self.assertEqual(len(npb_svi), 2)
def test_nexussviswitch_find(self):
"""Test Nexus switch selection for SVI placement."""
# Configure 2 Nexus switches
nexus_switches = {
('1.1.1.1', 'username'): 'admin',
('1.1.1.1', 'password'): 'password1',
('1.1.1.1', 'host1'): '1/1',
('2.2.2.2', 'username'): 'admin',
('2.2.2.2', 'password'): 'password2',
('2.2.2.2', 'host2'): '1/1',
}
nexus_plugin = cisco_nexus_plugin_v2.NexusPlugin()
nexus_plugin._client = mock.Mock()
nexus_plugin._client.nexus_switches = nexus_switches
# Set the Cisco config module's first configured device IP address
# according to the preceding switch config
with mock.patch.object(config, 'first_device_ip', new='1.1.1.1'):
# Enable round-robin mode with no SVIs configured on any of the
# Nexus switches (i.e. no entries in the SVI database). The
# plugin should select the first switch in the configuration.
config.CONF.set_override('svi_round_robin', True, 'CISCO')
switch_ip = nexus_plugin._find_switch_for_svi()
self.assertEqual(switch_ip, '1.1.1.1')
# Keep round-robin mode enabled, and add entries to the SVI
# database. The plugin should select the switch with the least
# number of entries in the SVI database.
vlan = 100
npbr11 = self._npb_test_obj('router', vlan, switch='1.1.1.1',
instance='instance11')
npbr12 = self._npb_test_obj('router', vlan, switch='1.1.1.1',
instance='instance12')
npbr21 = self._npb_test_obj('router', vlan, switch='2.2.2.2',
instance='instance21')
self._add_to_db([npbr11, npbr12, npbr21])
switch_ip = nexus_plugin._find_switch_for_svi()
self.assertEqual(switch_ip, '2.2.2.2')
# Disable round-robin mode. The plugin should select the
# first switch in the configuration.
config.CONF.clear_override('svi_round_robin', 'CISCO')
switch_ip = nexus_plugin._find_switch_for_svi()
self.assertEqual(switch_ip, '1.1.1.1')
def test_nexusbinding_update(self):
npb11 = self._npb_test_obj(10, 100, switch='1.1.1.1', instance='test')
npb21 = self._npb_test_obj(20, 100, switch='1.1.1.1', instance='test')

8
neutron/tests/unit/cisco/test_nexus_plugin.py
View File

@ -22,6 +22,7 @@ from neutron.extensions import providernet as provider
from neutron.openstack.common import importutils
from neutron.plugins.cisco.common import cisco_constants as const
from neutron.plugins.cisco.common import cisco_exceptions as cisco_exc
from neutron.plugins.cisco.common import config as cisco_config
from neutron.plugins.cisco.db import network_db_v2 as cdb
from neutron.plugins.cisco.nexus import cisco_nexus_plugin_v2
from neutron.tests import base
@ -146,12 +147,17 @@ class TestCiscoNexusPlugin(base.BaseTestCase):
self.patch_obj = mock.patch.dict('sys.modules',
{'ncclient': self.mock_ncclient})
self.patch_obj.start()
self.addCleanup(self.patch_obj.stop)
with mock.patch.object(cisco_nexus_plugin_v2.NexusPlugin,
'__init__', new=new_nexus_init):
self._cisco_nexus_plugin = cisco_nexus_plugin_v2.NexusPlugin()
self.addCleanup(self.patch_obj.stop)
# Set the Cisco config module's first configured device IP address
# according to the preceding switch config.
mock.patch.object(cisco_config, 'first_device_ip',
new=NEXUS_IP_ADDRESS).start()
self.addCleanup(mock.patch.stopall)
def test_create_delete_networks(self):
"""Tests creation of two new Virtual Networks."""