x/vmware-nsx
Code Issues Proposed changes

Refactor configuring of floating ips on a router

Browse Source 
This approach to configuring floating ips is stateless and idempotent.
This allows it to handle corner cases, such as reusing a floating ip
address with a different floating ip id in a way that is easier to
understand.

The concept is to wipe the floating ips clean and rebuild them each
time with the following optimizations.  To avoid bad performance in
manipulating iptables, it is called in the context of a call to
defer_apply_on.  To avoid a disruption in network flow a set
difference is use to determine the set of addresses that no longer
belong on the inteface rather than removing them all blindly.

Change-Id: I98aacbbb52b35688036990961d02e0b273504a77
Fixes: Bug #1209011
This commit is contained in:
Carl Baldwin 2013-09-27 04:04:31 +00:00
parent cdad785bc7
commit a65188fab0
3 changed files with 132 additions and 101 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

103
neutron/agent/l3_agent.py
View File

@ -50,6 +50,7 @@ NS_PREFIX = 'qrouter-'
INTERNAL_DEV_PREFIX = 'qr-'
EXTERNAL_DEV_PREFIX = 'qg-'
RPC_LOOP_INTERVAL = 1
FLOATING_IP_CIDR_SUFFIX = '/32'
class L3PluginApi(proxy.RpcProxy):
@ -95,7 +96,6 @@ class RouterInfo(object):
self._snat_enabled = None
self._snat_action = None
self.internal_ports = []
self.floating_ips = []
self.root_helper = root_helper
self.use_namespaces = use_namespaces
# Invoke the setter for establishing initial SNAT action
@ -409,7 +409,7 @@ class L3NATAgent(firewall_l3_agent.FWaaSL3AgentRpcCallback, manager.Manager):
internal_cidrs, interface_name)
# Process DNAT rules for floating IPs
if ex_gw_port or ri.ex_gw_port:
if ex_gw_port:
self.process_router_floating_ips(ri, ex_gw_port)
ri.ex_gw_port = ex_gw_port
@ -440,45 +440,46 @@ class L3NATAgent(firewall_l3_agent.FWaaSL3AgentRpcCallback, manager.Manager):
ri.iptables_manager.apply()
def process_router_floating_ips(self, ri, ex_gw_port):
floating_ips = ri.router.get(l3_constants.FLOATINGIP_KEY, [])
existing_floating_ip_ids = set([fip['id'] for fip in ri.floating_ips])
cur_floating_ip_ids = set([fip['id'] for fip in floating_ips])
"""Configure the router's floating IPs
Configures floating ips in iptables and on the router's gateway device.
id_to_fip_map = {}
Cleans up floating ips that should not longer be configured.
"""
interface_name = self.get_external_device_name(ex_gw_port['id'])
device = ip_lib.IPDevice(interface_name, self.root_helper,
namespace=ri.ns_name())
for fip in floating_ips:
if fip['port_id']:
if fip['id'] not in existing_floating_ip_ids:
ri.floating_ips.append(fip)
self.floating_ip_added(ri, ex_gw_port,
fip['floating_ip_address'],
fip['fixed_ip_address'])
# Clear out all iptables rules for floating ips
ri.iptables_manager.ipv4['nat'].clear_rules_by_tag('floating_ip')
# store to see if floatingip was remapped
id_to_fip_map[fip['id']] = fip
existing_cidrs = set([addr['cidr'] for addr in device.addr.list()])
new_cidrs = set()
floating_ip_ids_to_remove = (existing_floating_ip_ids -
cur_floating_ip_ids)
for fip in ri.floating_ips:
if fip['id'] in floating_ip_ids_to_remove:
ri.floating_ips.remove(fip)
self.floating_ip_removed(ri, ri.ex_gw_port,
fip['floating_ip_address'],
fip['fixed_ip_address'])
else:
# handle remapping of a floating IP
new_fip = id_to_fip_map[fip['id']]
new_fixed_ip = new_fip['fixed_ip_address']
existing_fixed_ip = fip['fixed_ip_address']
if (new_fixed_ip and existing_fixed_ip and
new_fixed_ip != existing_fixed_ip):
floating_ip = fip['floating_ip_address']
self.floating_ip_removed(ri, ri.ex_gw_port,
floating_ip, existing_fixed_ip)
self.floating_ip_added(ri, ri.ex_gw_port,
floating_ip, new_fixed_ip)
ri.floating_ips.remove(fip)
ri.floating_ips.append(new_fip)
# Loop once to ensure that floating ips are configured.
for fip in ri.router.get(l3_constants.FLOATINGIP_KEY, []):
fip_ip = fip['floating_ip_address']
ip_cidr = str(fip_ip) + FLOATING_IP_CIDR_SUFFIX
new_cidrs.add(ip_cidr)
if ip_cidr not in existing_cidrs:
net = netaddr.IPNetwork(ip_cidr)
device.addr.add(net.version, ip_cidr, str(net.broadcast))
self._send_gratuitous_arp_packet(ri, interface_name, fip_ip)
# Rebuild iptables rules for the floating ip.
fixed = fip['fixed_ip_address']
for chain, rule in self.floating_forward_rules(fip_ip, fixed):
ri.iptables_manager.ipv4['nat'].add_rule(chain, rule,
tag='floating_ip')
ri.iptables_manager.apply()
# Clean up addresses that no longer belong on the gateway interface.
for ip_cidr in existing_cidrs - new_cidrs:
if ip_cidr.endswith(FLOATING_IP_CIDR_SUFFIX):
net = netaddr.IPNetwork(ip_cidr)
device.addr.delete(net.version, ip_cidr)
def _get_ex_gw_port(self, ri):
return ri.router.get('gw_port')
@ -602,34 +603,6 @@ class L3NATAgent(firewall_l3_agent.FWaaSL3AgentRpcCallback, manager.Manager):
(internal_cidr, ex_gw_ip))]
return rules
def floating_ip_added(self, ri, ex_gw_port, floating_ip, fixed_ip):
ip_cidr = str(floating_ip) + '/32'
interface_name = self.get_external_device_name(ex_gw_port['id'])
device = ip_lib.IPDevice(interface_name, self.root_helper,
namespace=ri.ns_name())
if ip_cidr not in [addr['cidr'] for addr in device.addr.list()]:
net = netaddr.IPNetwork(ip_cidr)
device.addr.add(net.version, ip_cidr, str(net.broadcast))
self._send_gratuitous_arp_packet(ri, interface_name, floating_ip)
for chain, rule in self.floating_forward_rules(floating_ip, fixed_ip):
ri.iptables_manager.ipv4['nat'].add_rule(chain, rule)
ri.iptables_manager.apply()
def floating_ip_removed(self, ri, ex_gw_port, floating_ip, fixed_ip):
ip_cidr = str(floating_ip) + '/32'
net = netaddr.IPNetwork(ip_cidr)
interface_name = self.get_external_device_name(ex_gw_port['id'])
device = ip_lib.IPDevice(interface_name, self.root_helper,
namespace=ri.ns_name())
device.addr.delete(net.version, ip_cidr)
for chain, rule in self.floating_forward_rules(floating_ip, fixed_ip):
ri.iptables_manager.ipv4['nat'].remove_rule(chain, rule)
ri.iptables_manager.apply()
def floating_forward_rules(self, floating_ip, fixed_ip):
return [('PREROUTING', '-d %s -j DNAT --to %s' %
(floating_ip, fixed_ip)),

15
neutron/agent/linux/iptables_manager.py
View File

@ -63,12 +63,13 @@ class IptablesRule(object):
"""
def __init__(self, chain, rule, wrap=True, top=False,
binary_name=binary_name):
binary_name=binary_name, tag=None):
self.chain = get_chain_name(chain, wrap)
self.rule = rule
self.wrap = wrap
self.top = top
self.wrap_name = binary_name[:16]
self.tag = tag
def __eq__(self, other):
return ((self.chain == other.chain) and
@ -177,7 +178,7 @@ class IptablesTable(object):
self.rules = [r for r in self.rules
if jump_snippet not in r.rule]
def add_rule(self, chain, rule, wrap=True, top=False):
def add_rule(self, chain, rule, wrap=True, top=False, tag=None):
"""Add a rule to the table.
This is just like what you'd feed to iptables, just without
@ -195,7 +196,8 @@ class IptablesTable(object):
if '$' in rule:
rule = ' '.join(map(self._wrap_target_chain, rule.split(' ')))
self.rules.append(IptablesRule(chain, rule, wrap, top, self.wrap_name))
self.rules.append(IptablesRule(chain, rule, wrap, top, self.wrap_name,
tag))
def _wrap_target_chain(self, s):
if s.startswith('$'):
@ -231,6 +233,13 @@ class IptablesTable(object):
for rule in chained_rules:
self.rules.remove(rule)
def clear_rules_by_tag(self, tag):
if not tag:
return
rules = [rule for rule in self.rules if rule.tag == tag]
for rule in rules:
self.rules.remove(rule)
class IptablesManager(object):
"""Wrapper for iptables.

115
neutron/tests/unit/test_l3_agent.py
View File

@ -217,39 +217,6 @@ class TestBasicRouterOperations(base.BaseTestCase):
def test_agent_remove_external_gateway(self):
self._test_external_gateway_action('remove')
def _test_floating_ip_action(self, action):
router_id = _uuid()
ri = l3_agent.RouterInfo(router_id, self.conf.root_helper,
self.conf.use_namespaces, None)
agent = l3_agent.L3NATAgent(HOSTNAME, self.conf)
floating_ip = '20.0.0.100'
fixed_ip = '10.0.0.23'
ex_gw_port = {'fixed_ips': [{'ip_address': '20.0.0.30',
'subnet_id': _uuid()}],
'subnet': {'gateway_ip': '20.0.0.1'},
'id': _uuid(),
'mac_address': 'ca:fe:de:ad:be:ef',
'ip_cidr': '20.0.0.30/24'}
interface_name = agent.get_external_device_name(ex_gw_port['id'])
if action == 'add':
self.device_exists.return_value = False
agent.floating_ip_added(ri, ex_gw_port, floating_ip, fixed_ip)
self.send_arp.assert_called_once_with(ri, interface_name,
floating_ip)
elif action == 'remove':
self.device_exists.return_value = True
agent.floating_ip_removed(ri, ex_gw_port, floating_ip, fixed_ip)
else:
raise Exception("Invalid action %s" % action)
def test_agent_add_floating_ip(self):
self._test_floating_ip_action('add')
def test_agent_remove_floating_ip(self):
self._test_floating_ip_action('remove')
def _check_agent_method_called(self, agent, calls, namespace):
if namespace:
self.mock_ip.netns.execute.assert_has_calls(
@ -405,6 +372,7 @@ class TestBasicRouterOperations(base.BaseTestCase):
def test_process_router(self):
agent = l3_agent.L3NATAgent(HOSTNAME, self.conf)
agent.process_router_floating_ips = mock.Mock()
router = self._prepare_router_data()
fake_floatingips1 = {'floatingips': [
{'id': _uuid(),
@ -414,6 +382,9 @@ class TestBasicRouterOperations(base.BaseTestCase):
ri = l3_agent.RouterInfo(router['id'], self.conf.root_helper,
self.conf.use_namespaces, router=router)
agent.process_router(ri)
ex_gw_port = agent._get_ex_gw_port(ri)
agent.process_router_floating_ips.assert_called_with(ri, ex_gw_port)
agent.process_router_floating_ips.reset_mock()
# remap floating IP to a new fixed ip
fake_floatingips2 = copy.deepcopy(fake_floatingips1)
@ -421,16 +392,94 @@ class TestBasicRouterOperations(base.BaseTestCase):
router[l3_constants.FLOATINGIP_KEY] = fake_floatingips2['floatingips']
agent.process_router(ri)
ex_gw_port = agent._get_ex_gw_port(ri)
agent.process_router_floating_ips.assert_called_with(ri, ex_gw_port)
agent.process_router_floating_ips.reset_mock()
# remove just the floating ips
del router[l3_constants.FLOATINGIP_KEY]
agent.process_router(ri)
ex_gw_port = agent._get_ex_gw_port(ri)
agent.process_router_floating_ips.assert_called_with(ri, ex_gw_port)
agent.process_router_floating_ips.reset_mock()
# now no ports so state is torn down
del router[l3_constants.INTERFACE_KEY]
del router['gw_port']
agent.process_router(ri)
self.send_arp.assert_called_once()
self.assertFalse(agent.process_router_floating_ips.called)
@mock.patch('neutron.agent.linux.ip_lib.IPDevice')
def test_process_router_floating_ip_add(self, IPDevice):
fip = {
'id': _uuid(), 'port_id': _uuid(),
'floating_ip_address': '15.1.2.3',
'fixed_ip_address': '192.168.0.1'
}
IPDevice.return_value = device = mock.Mock()
device.addr.list.return_value = []
ri = mock.MagicMock()
ri.router.get.return_value = [fip]
agent = l3_agent.L3NATAgent(HOSTNAME, self.conf)
agent.process_router_floating_ips(ri, {'id': _uuid()})
device.addr.add.assert_called_once_with(4, '15.1.2.3/32', '15.1.2.3')
nat = ri.iptables_manager.ipv4['nat']
nat.clear_rules_by_tag.assert_called_once_with('floating_ip')
rules = agent.floating_forward_rules('15.1.2.3', '192.168.0.1')
for chain, rule in rules:
nat.add_rule.assert_any_call(chain, rule, tag='floating_ip')
@mock.patch('neutron.agent.linux.ip_lib.IPDevice')
def test_process_router_floating_ip_remove(self, IPDevice):
IPDevice.return_value = device = mock.Mock()
device.addr.list.return_value = [{'cidr': '15.1.2.3/32'}]
ri = mock.MagicMock()
ri.router.get.return_value = []
agent = l3_agent.L3NATAgent(HOSTNAME, self.conf)
agent.process_router_floating_ips(ri, {'id': _uuid()})
device.addr.delete.assert_called_once_with(4, '15.1.2.3/32')
nat = ri.iptables_manager.ipv4['nat']
nat = ri.iptables_manager.ipv4['nat']
nat.clear_rules_by_tag.assert_called_once_with('floating_ip')
@mock.patch('neutron.agent.linux.ip_lib.IPDevice')
def test_process_router_floating_ip_remap(self, IPDevice):
fip = {
'id': _uuid(), 'port_id': _uuid(),
'floating_ip_address': '15.1.2.3',
'fixed_ip_address': '192.168.0.2'
}
IPDevice.return_value = device = mock.Mock()
device.addr.list.return_value = [{'cidr': '15.1.2.3/32'}]
ri = mock.MagicMock()
ri.router.get.return_value = [fip]
agent = l3_agent.L3NATAgent(HOSTNAME, self.conf)
agent.process_router_floating_ips(ri, {'id': _uuid()})
self.assertFalse(device.addr.add.called)
self.assertFalse(device.addr.delete.called)
nat = ri.iptables_manager.ipv4['nat']
nat.clear_rules_by_tag.assert_called_once_with('floating_ip')
rules = agent.floating_forward_rules('15.1.2.3', '192.168.0.2')
for chain, rule in rules:
nat.add_rule.assert_any_call(chain, rule, tag='floating_ip')
def test_process_router_snat_disabled(self):
agent = l3_agent.L3NATAgent(HOSTNAME, self.conf)