neutron-openvswitch-agent代码分析
neutron.plugins.openvswitch.agent.ovs_neutron_agent:main
# init ovs first by agent_config：
# setup plugin_rpc, state_rpc, msgq consumer, periodically state report
# setup br-int, br-tun, bridge_mapping
# start sg_agent agent = OVSNeutronAgent(**agent_config) # start to process rpc events
# process port up/down and related flow update/local vlan bounding
# process security group updates agent.daemon_loop()
OVSNeutronAgent的初始化
class OVSNeutronAgent(n_rpc.RpcCallback, sg_rpc.SecurityGroupAgentRpcCallbackMixin, l2population_rpc.L2populationRpcCallBackMixin): '''Implements OVS-based tunneling, VLANs and flat networks. Two local bridges are created: an integration bridge (defaults to 'br-int') and a tunneling bridge (defaults to 'br-tun'). An additional bridge is created for each physical network interface used for VLANs and/or flat networks. All VM VIFs are plugged into the integration bridge. VM VIFs on a given virtual network share a common "local" VLAN (i.e. not propagated externally). The VLAN id of this local VLAN is mapped to the physical networking details realizing that virtual network. For virtual networks realized as GRE tunnels, a Logical Switch (LS) identifier is used to differentiate tenant traffic on inter-HV tunnels. A mesh of tunnels is created to other Hypervisors in the cloud. These tunnels originate and terminate on the tunneling bridge of each hypervisor. Port patching is done to connect local VLANs on the integration bridge to inter-hypervisor tunnels on the tunnel bridge. For each virtual network realized as a VLAN or flat network, a veth or a pair of patch ports is used to connect the local VLAN on the integration bridge with the physical network bridge, with flow rules adding, modifying, or stripping VLAN tags as necessary. ''' # history # 1.0 Initial version # 1.1 Support Security Group RPC RPC_API_VERSION = '1.1' def __init__(self, integ_br, tun_br, local_ip, bridge_mappings, root_helper, polling_interval, tunnel_types=None, veth_mtu=None, l2_population=False, minimize_polling=False, ovsdb_monitor_respawn_interval=( constants.DEFAULT_OVSDBMON_RESPAWN), arp_responder=False, use_veth_interconnection=False): '''Constructor. :param integ_br: name of the integration bridge. :param tun_br: name of the tunnel bridge. :param local_ip: local IP address of this hypervisor. :param bridge_mappings: mappings from physical network name to bridge. :param root_helper: utility to use when running shell cmds. :param polling_interval: interval (secs) to poll DB. :param tunnel_types: A list of tunnel types to enable support for in the agent. If set, will automatically set enable_tunneling to True. :param veth_mtu: MTU size for veth interfaces. :param l2_population: Optional, whether L2 population is turned on :param minimize_polling: Optional, whether to minimize polling by monitoring ovsdb for interface changes. :param ovsdb_monitor_respawn_interval: Optional, when using polling minimization, the number of seconds to wait before respawning the ovsdb monitor. :param arp_responder: Optional, enable local ARP responder if it is supported. :param use_veth_interconnection: use veths instead of patch ports to interconnect the integration bridge to physical bridges. ''' super(OVSNeutronAgent, self).__init__() self.use_veth_interconnection = use_veth_interconnection self.veth_mtu = veth_mtu self.root_helper = root_helper self.available_local_vlans = set(moves.xrange(q_const.MIN_VLAN_TAG, # 1-1094 q_const.MAX_VLAN_TAG)) self.tunnel_types = tunnel_types or [] self.l2_pop = l2_population # TODO(ethuleau): Initially, local ARP responder is be dependent to the # ML2 l2 population mechanism driver. self.arp_responder_enabled = (arp_responder and self._check_arp_responder_support() and self.l2_pop) self.agent_state = { 'binary': 'neutron-openvswitch-agent', 'host': cfg.CONF.host, 'topic': q_const.L2_AGENT_TOPIC, 'configurations': {'bridge_mappings': bridge_mappings, 'tunnel_types': self.tunnel_types, 'tunneling_ip': local_ip, 'l2_population': self.l2_pop, 'arp_responder_enabled': self.arp_responder_enabled}, 'agent_type': q_const.AGENT_TYPE_OVS, 'start_flag': True} # Keep track of int_br's device count for use by _report_state() self.int_br_device_count = 0 self.int_br = ovs_lib.OVSBridge(integ_br, self.root_helper) # Create integration bridge and patch ports, # remove all existing flows, and then witch all traffic using L2 learning # add a canary flow to int_br to track OVS restarts self.setup_integration_br() # Stores port update notifications for processing in main rpc loop self.updated_ports = set() # state_rpc: periodically report state by topic q-plugin # plugin_rpc:communicate with plugin by topic q-agent-notifier # consumer topic id includes: # q-agent-notifier-port_update # q-agent-notifier-network_delete # q-agent-notifier-tunnel_update # q-agent-notifier-security_group_update # q-agent-notifier-l2population_update （需要启动l2populcation） self.setup_rpc() # bridge_mappings = default:br-eth1 self.bridge_mappings = bridge_mappings # Creates physical network bridges and links them to integration bridge using veths. self.setup_physical_bridges(self.bridge_mappings) self.local_vlan_map = {} self.tun_br_ofports = {p_const.TYPE_GRE: {}, p_const.TYPE_VXLAN: {}} self.polling_interval = polling_interval self.minimize_polling = minimize_polling self.ovsdb_monitor_respawn_interval = ovsdb_monitor_respawn_interval if tunnel_types: self.enable_tunneling = True else: self.enable_tunneling = False self.local_ip = local_ip self.tunnel_count = 0 self.vxlan_udp_port = cfg.CONF.AGENT.vxlan_udp_port self.dont_fragment = cfg.CONF.AGENT.dont_fragment self.tun_br = None # Creates tunnel bridge, and links it to the integration bridge # using a patch port. # create default flow tables if self.enable_tunneling: self.setup_tunnel_br(tun_br) # Collect additional bridges to monitor # Setup ancillary bridges - for example br-ex self.ancillary_brs = self.setup_ancillary_bridges(integ_br, tun_br) # Security group agent support # firewall_driver = neutron.agent.linux.iptables_firewall.OVSHybridIptablesFirewallDriver self.sg_agent = OVSSecurityGroupAgent(self.context, self.plugin_rpc, root_helper) # Initialize iteration counter self.iter_num = 0 self.run_daemon_loop = True
OVSNeutronAgent初始化完成后启动agent.daemon_loop()
def daemon_loop(self): with polling.get_polling_manager( self.minimize_polling, self.root_helper, self.ovsdb_monitor_respawn_interval) as pm: self.rpc_loop(polling_manager=pm)
rpc_loop
def rpc_loop(self, polling_manager=None): # sync tunnel and check ovs restart if not polling_manager: polling_manager = polling.AlwaysPoll() sync = True ports = set() updated_ports_copy = set() ancillary_ports = set() tunnel_sync = True ovs_restarted = False while self.run_daemon_loop: start = time.time() port_stats = {'regular': {'added': 0, 'updated': 0, 'removed': 0}, 'ancillary': {'added': 0, 'removed': 0}} LOG.debug(_("Agent rpc_loop - iteration:%d started"), self.iter_num) if sync: LOG.info(_("Agent out of sync with plugin!")) ports.clear() ancillary_ports.clear() sync = False polling_manager.force_polling() # check ovs restart by checking exist for the canary flow ovs_restarted = self.check_ovs_restart() if ovs_restarted: # reset br-int, br-tun, and other physical bridges self.setup_integration_br() self.setup_physical_bridges(self.bridge_mappings) if self.enable_tunneling: self.setup_tunnel_br() tunnel_sync = True # Notify the plugin of tunnel IP if self.enable_tunneling and tunnel_sync: LOG.info(_("Agent tunnel out of sync with plugin!")) try: tunnel_sync = self.tunnel_sync() except Exception: LOG.exception(_("Error while synchronizing tunnels")) tunnel_sync = True # check if ports/security_groups updates and perform update if self._agent_has_updates(polling_manager) or ovs_restarted: try: LOG.debug(_("Agent rpc_loop - iteration:%(iter_num)d - " "starting polling. Elapsed:%(elapsed).3f"), {'iter_num': self.iter_num, 'elapsed': time.time() - start}) # Save updated ports dict to perform rollback in # case resync would be needed, and then clear # self.updated_ports. As the greenthread should not yield # between these two statements, this will be thread-safe updated_ports_copy = self.updated_ports self.updated_ports = set() reg_ports = (set() if ovs_restarted else ports) # { # 'current': ['ovs-vsctl', --format=json', '--', '--columns=name,external_ids,ofport','list', 'Interface'] and then filted in get_vif_port_set() # 'updated': check_changed_vlans() returns a set of port ids of the ports concerned by a vlan tag loss, and then updated_ports &= cur_ports # 'added' : cur_ports - registered_ports # 'removed': registered_ports - cur_ports # } port_info = self.scan_ports(reg_ports, updated_ports_copy) LOG.debug(_("Agent rpc_loop - iteration:%(iter_num)d - " "port information retrieved. " "Elapsed:%(elapsed).3f"), {'iter_num': self.iter_num, 'elapsed': time.time() - start}) # Secure and wire/unwire VIFs and update their status # on Neutron server if (self._port_info_has_changes(port_info) or self.sg_agent.firewall_refresh_needed() or ovs_restarted): LOG.debug(_("Starting to process devices in:%s"), port_info) # If treat devices fails - must resync with plugin sync = self.process_network_ports(port_info, ovs_restarted) LOG.debug(_("Agent rpc_loop - iteration:%(iter_num)d -" "ports processed. Elapsed:%(elapsed).3f"), {'iter_num': self.iter_num, 'elapsed': time.time() - start}) port_stats['regular']['added'] = ( len(port_info.get('added', []))) port_stats['regular']['updated'] = ( len(port_info.get('updated', []))) port_stats['regular']['removed'] = ( len(port_info.get('removed', []))) ports = port_info['current'] # Treat ancillary devices if they exist if self.ancillary_brs: port_info = self.update_ancillary_ports( ancillary_ports) LOG.debug(_("Agent rpc_loop - iteration:%(iter_num)d -" "ancillary port info retrieved. " "Elapsed:%(elapsed).3f"), {'iter_num': self.iter_num, 'elapsed': time.time() - start}) if port_info: rc = self.process_ancillary_network_ports( port_info) LOG.debug(_("Agent rpc_loop - iteration:" "%(iter_num)d - ancillary ports " "processed. Elapsed:%(elapsed).3f"), {'iter_num': self.iter_num, 'elapsed': time.time() - start}) ancillary_ports = port_info['current'] port_stats['ancillary']['added'] = ( len(port_info.get('added', []))) port_stats['ancillary']['removed'] = ( len(port_info.get('removed', []))) sync = sync | rc polling_manager.polling_completed() except Exception: LOG.exception(_("Error while processing VIF ports")) # Put the ports back in self.updated_port self.updated_ports |= updated_ports_copy sync = True # sleep till end of polling interval elapsed = (time.time() - start) LOG.debug(_("Agent rpc_loop - iteration:%(iter_num)d " "completed. Processed ports statistics: " "%(port_stats)s. Elapsed:%(elapsed).3f"), {'iter_num': self.iter_num, 'port_stats': port_stats, 'elapsed': elapsed}) if (elapsed < self.polling_interval): time.sleep(self.polling_interval - elapsed) else: LOG.debug(_("Loop iteration exceeded interval " "(%(polling_interval)s vs. %(elapsed)s)!"), {'polling_interval': self.polling_interval, 'elapsed': elapsed}) self.iter_num = self.iter_num + 1
rpc_loop()中最重要的两个函数为tunnel_sync(查询并建立隧道)和process_network_ports(处理port和安全组变更)
tunnel_sync 查询并建立隧道
def tunnel_sync(self): resync = False try: for tunnel_type in self.tunnel_types: # tunnel_types = vxlan, gre # query tunnel details from plugin_rpc by local_ip and tunnel_type details = self.plugin_rpc.tunnel_sync(self.context, self.local_ip, tunnel_type) # establish tunnel with all other tunnel_ip if l2_pop disabled # if l2_pop enabled, tunnel sync is processed by agent in q-agent-notifier-l2population_update consumer id if not self.l2_pop: tunnels = details['tunnels'] for tunnel in tunnels: if self.local_ip != tunnel['ip_address']: tunnel_id = tunnel.get('id') # Unlike the OVS plugin, ML2 doesn't return an id # key. So use ip_address to form port name instead. # Port name must be <=15 chars, so use shorter hex. remote_ip = tunnel['ip_address'] remote_ip_hex = self.get_ip_in_hex(remote_ip) if not tunnel_id and not remote_ip_hex: continue tun_name = '%s-%s' % (tunnel_type, tunnel_id or remote_ip_hex) # setup tunnel_port and related flows self.setup_tunnel_port(tun_name, tunnel['ip_address'], tunnel_type) except Exception as e: LOG.debug(_("Unable to sync tunnel IP %(local_ip)s: %(e)s"), {'local_ip': self.local_ip, 'e': e}) resync = True return resync
process_network_ports 处理port和安全组变更
def process_network_ports(self, port_info, ovs_restarted): resync_a = False resync_b = False # TODO(salv-orlando): consider a solution for ensuring notifications # are processed exactly in the same order in which they were # received. This is tricky because there are two notification # sources: the neutron server, and the ovs db monitor process # If there is an exception while processing security groups ports # will not be wired anyway, and a resync will be triggered # TODO(salv-orlando): Optimize avoiding applying filters unnecessarily # (eg: when there are no IP address changes) # 通过plugin_rpc到plugin查询安全组，然后通过sg_agent应用安全组 self.sg_agent.setup_port_filters(port_info.get('added', set()), port_info.get('updated', set())) # VIF wiring needs to be performed always for 'new' devices. # For updated ports, re-wiring is not needed in most cases, but needs # to be performed anyway when the admin state of a device is changed. # A device might be both in the 'added' and 'updated' # list at the same time; avoid processing it twice. devices_added_updated = (port_info.get('added', set()) | port_info.get('updated', set())) if devices_added_updated: start = time.time() try: # 添加或更新的ports: 查询port详细信息后通知plugin port up/down，接着再port_bound/port_dead skipped_devices = self.treat_devices_added_or_updated( devices_added_updated, ovs_restarted) LOG.debug(_("process_network_ports - iteration:%(iter_num)d -" "treat_devices_added_or_updated completed. " "Skipped %(num_skipped)d devices of " "%(num_current)d devices currently available. " "Time elapsed: %(elapsed).3f"), {'iter_num': self.iter_num, 'num_skipped': len(skipped_devices), 'num_current': len(port_info['current']), 'elapsed': time.time() - start}) # Update the list of current ports storing only those which # have been actually processed. port_info['current'] = (port_info['current'] - set(skipped_devices)) except DeviceListRetrievalError: # Need to resync as there was an error with server # communication. LOG.exception(_("process_network_ports - iteration:%d - " "failure while retrieving port details " "from server"), self.iter_num) resync_a = True if 'removed' in port_info: start = time.time() # 删除的port：删除安全组，通知plugin port down, 并unbound local_vlan， resync_b = self.treat_devices_removed(port_info['removed']) LOG.debug(_("process_network_ports - iteration:%(iter_num)d -" "treat_devices_removed completed in %(elapsed).3f"), {'iter_num': self.iter_num, 'elapsed': time.time() - start}) # If one of the above operations fails => resync with plugin return (resync_a | resync_b)
neutron-ovs-cleanup
This service starts on boot and ensures that Networking has full control over the creation and management of tap devices.
def main(): """Main method for cleaning up OVS bridges. The utility cleans up the integration bridges used by Neutron. """ conf = setup_conf() conf() config.setup_logging(conf) configuration_bridges = set([conf.ovs_integration_bridge, conf.external_network_bridge]) ovs_bridges = set(ovs_lib.get_bridges(conf.AGENT.root_helper)) available_configuration_bridges = configuration_bridges & ovs_bridges if conf.ovs_all_ports: bridges = ovs_bridges else: bridges = available_configuration_bridges # Collect existing ports created by Neutron on configuration bridges. # After deleting ports from OVS bridges, we cannot determine which # ports were created by Neutron, so port information is collected now. ports = collect_neutron_ports(available_configuration_bridges, conf.AGENT.root_helper) for bridge in bridges: LOG.info(_("Cleaning %s"), bridge) ovs = ovs_lib.OVSBridge(bridge, conf.AGENT.root_helper) ovs.delete_ports(all_ports=conf.ovs_all_ports) # Remove remaining ports created by Neutron (usually veth pair) delete_neutron_ports(ports, conf.AGENT.root_helper) LOG.info(_("OVS cleanup completed successfully"))
最后看下nova与neutron-openvswitch-agent的交互，这张图片来源于GongYongSheng在香港峰会的PPT：
首先boot虚机时，nova-compute发消息给neutron-server请求创建port。之后，在driver里面在br-int上建立 port后，neutron-openvswitch-port循环检测br-int会发现新增端口,对其设定合适的openflow规则以及 localvlan，最后将port状态设置为ACTIVE。
参考：http://blog.csdn.net/matt_mao/article/details/20706689