# Copyright 2012 OpenStack Foundation # 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. import collections import os import eventlet from oslo_config import cfg from oslo_log import log as logging import oslo_messaging from oslo_service import loopingcall from oslo_utils import importutils from neutron.agent.linux import dhcp from neutron.agent.linux import external_process from neutron.agent.metadata import driver as metadata_driver from neutron.agent import rpc as agent_rpc from neutron.common import constants from neutron.common import exceptions from neutron.common import rpc as n_rpc from neutron.common import topics from neutron.common import utils from neutron import context from neutron.i18n import _LE, _LI, _LW from neutron import manager LOG = logging.getLogger(__name__) class DhcpAgent(manager.Manager): """DHCP agent service manager. Note that the public methods of this class are exposed as the server side of an rpc interface. The neutron server uses neutron.api.rpc.agentnotifiers.dhcp_rpc_agent_api.DhcpAgentNotifyApi as the client side to execute the methods here. For more information about changing rpc interfaces, see doc/source/devref/rpc_api.rst. """ target = oslo_messaging.Target(version='1.0') def __init__(self, host=None, conf=None): super(DhcpAgent, self).__init__(host=host) self.needs_resync_reasons = collections.defaultdict(list) self.conf = conf or cfg.CONF self.cache = NetworkCache() self.dhcp_driver_cls = importutils.import_class(self.conf.dhcp_driver) ctx = context.get_admin_context_without_session() self.plugin_rpc = DhcpPluginApi(topics.PLUGIN, ctx, self.conf.use_namespaces, self.conf.host) # create dhcp dir to store dhcp info dhcp_dir = os.path.dirname("/%s/dhcp/" % self.conf.state_path) utils.ensure_dir(dhcp_dir) self.dhcp_version = self.dhcp_driver_cls.check_version() self._populate_networks_cache() self._process_monitor = external_process.ProcessMonitor( config=self.conf, resource_type='dhcp') def init_host(self): self.sync_state() def _populate_networks_cache(self): """Populate the networks cache when the DHCP-agent starts.""" try: existing_networks = self.dhcp_driver_cls.existing_dhcp_networks( self.conf ) for net_id in existing_networks: net = dhcp.NetModel(self.conf.use_namespaces, {"id": net_id, "subnets": [], "ports": []}) self.cache.put(net) except NotImplementedError: # just go ahead with an empty networks cache LOG.debug("The '%s' DHCP-driver does not support retrieving of a " "list of existing networks", self.conf.dhcp_driver) def after_start(self): self.run() LOG.info(_LI("DHCP agent started")) def run(self): """Activate the DHCP agent.""" self.sync_state() self.periodic_resync() def call_driver(self, action, network, **action_kwargs): """Invoke an action on a DHCP driver instance.""" LOG.debug('Calling driver for network: %(net)s action: %(action)s', {'net': network.id, 'action': action}) try: # the Driver expects something that is duck typed similar to # the base models. driver = self.dhcp_driver_cls(self.conf, network, self._process_monitor, self.dhcp_version, self.plugin_rpc) getattr(driver, action)(**action_kwargs) return True except exceptions.Conflict: # No need to resync here, the agent will receive the event related # to a status update for the network LOG.warning(_LW('Unable to %(action)s dhcp for %(net_id)s: there ' 'is a conflict with its current state; please ' 'check that the network and/or its subnet(s) ' 'still exist.'), {'net_id': network.id, 'action': action}) except Exception as e: if getattr(e, 'exc_type', '') != 'IpAddressGenerationFailure': # Don't resync if port could not be created because of an IP # allocation failure. When the subnet is updated with a new # allocation pool or a port is deleted to free up an IP, this # will automatically be retried on the notification self.schedule_resync(e, network.id) if (isinstance(e, oslo_messaging.RemoteError) and e.exc_type == 'NetworkNotFound' or isinstance(e, exceptions.NetworkNotFound)): LOG.warning(_LW("Network %s has been deleted."), network.id) else: LOG.exception(_LE('Unable to %(action)s dhcp for %(net_id)s.'), {'net_id': network.id, 'action': action}) def schedule_resync(self, reason, network_id=None): """Schedule a resync for a given network and reason. If no network is specified, resync all networks. """ self.needs_resync_reasons[network_id].append(reason) @utils.synchronized('dhcp-agent') def sync_state(self, networks=None): """Sync the local DHCP state with Neutron. If no networks are passed, or 'None' is one of the networks, sync all of the networks. """ only_nets = set([] if (not networks or None in networks) else networks) LOG.info(_LI('Synchronizing state')) pool = eventlet.GreenPool(self.conf.num_sync_threads) known_network_ids = set(self.cache.get_network_ids()) try: active_networks = self.plugin_rpc.get_active_networks_info() active_network_ids = set(network.id for network in active_networks) for deleted_id in known_network_ids - active_network_ids: try: self.disable_dhcp_helper(deleted_id) except Exception as e: self.schedule_resync(e, deleted_id) LOG.exception(_LE('Unable to sync network state on ' 'deleted network %s'), deleted_id) for network in active_networks: if (not only_nets or # specifically resync all network.id not in known_network_ids or # missing net network.id in only_nets): # specific network to sync pool.spawn(self.safe_configure_dhcp_for_network, network) pool.waitall() LOG.info(_LI('Synchronizing state complete')) except Exception as e: if only_nets: for network_id in only_nets: self.schedule_resync(e, network_id) else: self.schedule_resync(e) LOG.exception(_LE('Unable to sync network state.')) @utils.exception_logger() def _periodic_resync_helper(self): """Resync the dhcp state at the configured interval.""" while True: eventlet.sleep(self.conf.resync_interval) if self.needs_resync_reasons: # be careful to avoid a race with additions to list # from other threads reasons = self.needs_resync_reasons self.needs_resync_reasons = collections.defaultdict(list) for net, r in reasons.items(): if not net: net = "*" LOG.debug("resync (%(network)s): %(reason)s", {"reason": r, "network": net}) self.sync_state(reasons.keys()) def periodic_resync(self): """Spawn a thread to periodically resync the dhcp state.""" eventlet.spawn(self._periodic_resync_helper) def safe_get_network_info(self, network_id): try: network = self.plugin_rpc.get_network_info(network_id) if not network: LOG.warn(_LW('Network %s has been deleted.'), network_id) return network except Exception as e: self.schedule_resync(e, network_id) LOG.exception(_LE('Network %s info call failed.'), network_id) def enable_dhcp_helper(self, network_id): """Enable DHCP for a network that meets enabling criteria.""" network = self.safe_get_network_info(network_id) if network: self.configure_dhcp_for_network(network) @utils.exception_logger() def safe_configure_dhcp_for_network(self, network): try: self.configure_dhcp_for_network(network) except (exceptions.NetworkNotFound, RuntimeError): LOG.warn(_LW('Network %s may have been deleted and its resources ' 'may have already been disposed.'), network.id) def configure_dhcp_for_network(self, network): if not network.admin_state_up: return enable_metadata = self.dhcp_driver_cls.should_enable_metadata( self.conf, network) dhcp_network_enabled = False for subnet in network.subnets: if subnet.enable_dhcp: if self.call_driver('enable', network): dhcp_network_enabled = True self.cache.put(network) break if enable_metadata and dhcp_network_enabled: for subnet in network.subnets: if subnet.ip_version == 4 and subnet.enable_dhcp: self.enable_isolated_metadata_proxy(network) break def disable_dhcp_helper(self, network_id): """Disable DHCP for a network known to the agent.""" network = self.cache.get_network_by_id(network_id) if network: if (self.conf.use_namespaces and self.conf.enable_isolated_metadata): # NOTE(jschwarz): In the case where a network is deleted, all # the subnets and ports are deleted before this function is # called, so checking if 'should_enable_metadata' is True # for any subnet is false logic here. self.disable_isolated_metadata_proxy(network) if self.call_driver('disable', network): self.cache.remove(network) def refresh_dhcp_helper(self, network_id): """Refresh or disable DHCP for a network depending on the current state of the network. """ old_network = self.cache.get_network_by_id(network_id) if not old_network: # DHCP current not running for network. return self.enable_dhcp_helper(network_id) network = self.safe_get_network_info(network_id) if not network: return old_cidrs = set(s.cidr for s in old_network.subnets if s.enable_dhcp) new_cidrs = set(s.cidr for s in network.subnets if s.enable_dhcp) if new_cidrs and old_cidrs == new_cidrs: self.call_driver('reload_allocations', network) self.cache.put(network) elif new_cidrs: if self.call_driver('restart', network): self.cache.put(network) else: self.disable_dhcp_helper(network.id) @utils.synchronized('dhcp-agent') def network_create_end(self, context, payload): """Handle the network.create.end notification event.""" network_id = payload['network']['id'] self.enable_dhcp_helper(network_id) @utils.synchronized('dhcp-agent') def network_update_end(self, context, payload): """Handle the network.update.end notification event.""" network_id = payload['network']['id'] if payload['network']['admin_state_up']: self.enable_dhcp_helper(network_id) else: self.disable_dhcp_helper(network_id) @utils.synchronized('dhcp-agent') def network_delete_end(self, context, payload): """Handle the network.delete.end notification event.""" self.disable_dhcp_helper(payload['network_id']) @utils.synchronized('dhcp-agent') def subnet_update_end(self, context, payload): """Handle the subnet.update.end notification event.""" network_id = payload['subnet']['network_id'] self.refresh_dhcp_helper(network_id) # Use the update handler for the subnet create event. subnet_create_end = subnet_update_end @utils.synchronized('dhcp-agent') def subnet_delete_end(self, context, payload): """Handle the subnet.delete.end notification event.""" subnet_id = payload['subnet_id'] network = self.cache.get_network_by_subnet_id(subnet_id) if network: self.refresh_dhcp_helper(network.id) @utils.synchronized('dhcp-agent') def port_update_end(self, context, payload): """Handle the port.update.end notification event.""" updated_port = dhcp.DictModel(payload['port']) network = self.cache.get_network_by_id(updated_port.network_id) if network: driver_action = 'reload_allocations' if self._is_port_on_this_agent(updated_port): orig = self.cache.get_port_by_id(updated_port['id']) # assume IP change if not in cache old_ips = {i['ip_address'] for i in orig['fixed_ips'] or []} new_ips = {i['ip_address'] for i in updated_port['fixed_ips']} if old_ips != new_ips: driver_action = 'restart' self.cache.put_port(updated_port) self.call_driver(driver_action, network) def _is_port_on_this_agent(self, port): thishost = utils.get_dhcp_agent_device_id( port['network_id'], self.conf.host) return port['device_id'] == thishost # Use the update handler for the port create event. port_create_end = port_update_end @utils.synchronized('dhcp-agent') def port_delete_end(self, context, payload): """Handle the port.delete.end notification event.""" port = self.cache.get_port_by_id(payload['port_id']) if port: network = self.cache.get_network_by_id(port.network_id) self.cache.remove_port(port) self.call_driver('reload_allocations', network) def enable_isolated_metadata_proxy(self, network): # The proxy might work for either a single network # or all the networks connected via a router # to the one passed as a parameter kwargs = {'network_id': network.id} # When the metadata network is enabled, the proxy might # be started for the router attached to the network if self.conf.enable_metadata_network: router_ports = [port for port in network.ports if (port.device_owner in constants.ROUTER_INTERFACE_OWNERS)] if router_ports: # Multiple router ports should not be allowed if len(router_ports) > 1: LOG.warning(_LW("%(port_num)d router ports found on the " "metadata access network. Only the port " "%(port_id)s, for router %(router_id)s " "will be considered"), {'port_num': len(router_ports), 'port_id': router_ports[0].id, 'router_id': router_ports[0].device_id}) kwargs = {'router_id': router_ports[0].device_id} metadata_driver.MetadataDriver.spawn_monitored_metadata_proxy( self._process_monitor, network.namespace, dhcp.METADATA_PORT, self.conf, **kwargs) def disable_isolated_metadata_proxy(self, network): metadata_driver.MetadataDriver.destroy_monitored_metadata_proxy( self._process_monitor, network.id, self.conf) class DhcpPluginApi(object): """Agent side of the dhcp rpc API. This class implements the client side of an rpc interface. The server side of this interface can be found in neutron.api.rpc.handlers.dhcp_rpc.DhcpRpcCallback. For more information about changing rpc interfaces, see doc/source/devref/rpc_api.rst. API version history: 1.0 - Initial version. 1.1 - Added get_active_networks_info, create_dhcp_port, and update_dhcp_port methods. """ def __init__(self, topic, context, use_namespaces, host): self.context = context self.host = host self.use_namespaces = use_namespaces target = oslo_messaging.Target( topic=topic, namespace=constants.RPC_NAMESPACE_DHCP_PLUGIN, version='1.0') self.client = n_rpc.get_client(target) def get_active_networks_info(self): """Make a remote process call to retrieve all network info.""" cctxt = self.client.prepare(version='1.1') networks = cctxt.call(self.context, 'get_active_networks_info', host=self.host) return [dhcp.NetModel(self.use_namespaces, n) for n in networks] def get_network_info(self, network_id): """Make a remote process call to retrieve network info.""" cctxt = self.client.prepare() network = cctxt.call(self.context, 'get_network_info', network_id=network_id, host=self.host) if network: return dhcp.NetModel(self.use_namespaces, network) def create_dhcp_port(self, port): """Make a remote process call to create the dhcp port.""" cctxt = self.client.prepare(version='1.1') port = cctxt.call(self.context, 'create_dhcp_port', port=port, host=self.host) if port: return dhcp.DictModel(port) def update_dhcp_port(self, port_id, port): """Make a remote process call to update the dhcp port.""" cctxt = self.client.prepare(version='1.1') port = cctxt.call(self.context, 'update_dhcp_port', port_id=port_id, port=port, host=self.host) if port: return dhcp.DictModel(port) def release_dhcp_port(self, network_id, device_id): """Make a remote process call to release the dhcp port.""" cctxt = self.client.prepare() return cctxt.call(self.context, 'release_dhcp_port', network_id=network_id, device_id=device_id, host=self.host) class NetworkCache(object): """Agent cache of the current network state.""" def __init__(self): self.cache = {} self.subnet_lookup = {} self.port_lookup = {} def get_network_ids(self): return self.cache.keys() def get_network_by_id(self, network_id): return self.cache.get(network_id) def get_network_by_subnet_id(self, subnet_id): return self.cache.get(self.subnet_lookup.get(subnet_id)) def get_network_by_port_id(self, port_id): return self.cache.get(self.port_lookup.get(port_id)) def put(self, network): if network.id in self.cache: self.remove(self.cache[network.id]) self.cache[network.id] = network for subnet in network.subnets: self.subnet_lookup[subnet.id] = network.id for port in network.ports: self.port_lookup[port.id] = network.id def remove(self, network): del self.cache[network.id] for subnet in network.subnets: del self.subnet_lookup[subnet.id] for port in network.ports: del self.port_lookup[port.id] def put_port(self, port): network = self.get_network_by_id(port.network_id) for index in range(len(network.ports)): if network.ports[index].id == port.id: network.ports[index] = port break else: network.ports.append(port) self.port_lookup[port.id] = network.id def remove_port(self, port): network = self.get_network_by_port_id(port.id) for index in range(len(network.ports)): if network.ports[index] == port: del network.ports[index] del self.port_lookup[port.id] break def get_port_by_id(self, port_id): network = self.get_network_by_port_id(port_id) if network: for port in network.ports: if port.id == port_id: return port def get_state(self): net_ids = self.get_network_ids() num_nets = len(net_ids) num_subnets = 0 num_ports = 0 for net_id in net_ids: network = self.get_network_by_id(net_id) num_subnets += len(network.subnets) num_ports += len(network.ports) return {'networks': num_nets, 'subnets': num_subnets, 'ports': num_ports} class DhcpAgentWithStateReport(DhcpAgent): def __init__(self, host=None, conf=None): super(DhcpAgentWithStateReport, self).__init__(host=host, conf=conf) self.state_rpc = agent_rpc.PluginReportStateAPI(topics.REPORTS) self.agent_state = { 'binary': 'neutron-dhcp-agent', 'host': host, 'availability_zone': self.conf.AGENT.availability_zone, 'topic': topics.DHCP_AGENT, 'configurations': { 'dhcp_driver': self.conf.dhcp_driver, 'use_namespaces': self.conf.use_namespaces, 'dhcp_lease_duration': self.conf.dhcp_lease_duration, 'log_agent_heartbeats': self.conf.AGENT.log_agent_heartbeats}, 'start_flag': True, 'agent_type': constants.AGENT_TYPE_DHCP} report_interval = self.conf.AGENT.report_interval if report_interval: self.heartbeat = loopingcall.FixedIntervalLoopingCall( self._report_state) self.heartbeat.start(interval=report_interval) def _report_state(self): try: self.agent_state.get('configurations').update( self.cache.get_state()) ctx = context.get_admin_context_without_session() agent_status = self.state_rpc.report_state( ctx, self.agent_state, True) if agent_status == constants.AGENT_REVIVED: LOG.info(_LI("Agent has just been revived. " "Scheduling full sync")) self.schedule_resync("Agent has just been revived") except AttributeError: # This means the server does not support report_state LOG.warn(_LW("Neutron server does not support state report." " State report for this agent will be disabled.")) self.heartbeat.stop() self.run() return except Exception: LOG.exception(_LE("Failed reporting state!")) return if self.agent_state.pop('start_flag', None): self.run() def agent_updated(self, context, payload): """Handle the agent_updated notification event.""" self.schedule_resync(_("Agent updated: %(payload)s") % {"payload": payload}) LOG.info(_LI("agent_updated by server side %s!"), payload) def after_start(self): LOG.info(_LI("DHCP agent started"))