nova-compute创建虚拟机分配network过程
在/nova/compute/manager.py中：
def _build_instance(self, context, request_spec, filter_properties,
requested_networks, injected_files, admin_password, is_first_time,
node, instance, image_meta, legacy_bdm_in_spec):
context = context.elevated()
...
try:
limits = filter_properties.get('limits', {})
with rt.instance_claim(context, instance, limits):
macs = self.driver.macs_for_instance(instance)
dhcp_options = self.driver.dhcp_options_for_instance(instance)
network_info = self._allocate_network(context, instance,
requested_networks, macs, security_groups,
dhcp_options)
...
return instance, network_info
通过_allocate_network()，创建必要的port和security group。
def _allocate_network(self, context, instance, requested_networks, macs,
security_groups, dhcp_options):
"""Start network allocation asynchronously. Return an instance
of NetworkInfoAsyncWrapper that can be used to retrieve the
allocated networks when the operation has finished.
"""
# NOTE(comstud): Since we're allocating networks asynchronously,
# this task state has little meaning, as we won't be in this
# state for very long.
instance = self._instance_update(context, instance['uuid'],
vm_state=vm_states.BUILDING,
task_state=task_states.NETWORKING,
expected_task_state=[None])
is_vpn = pipelib.is_vpn_image(instance['image_ref'])
return network_model.NetworkInfoAsyncWrapper(
self._allocate_network_async, context, instance,
requested_networks, macs, security_groups, is_vpn,
dhcp_options)
network_model.NetworkInfoAsyncWrapper()创建一个异步的wrapper，返回执行_allocate_network_async()的结果。
def _allocate_network_async(self, context, instance, requested_networks,
macs, security_groups, is_vpn, dhcp_options):
...
for attempt in range(1, attempts + 1):
try:
nwinfo = self.network_api.allocate_for_instance(
context, instance, vpn=is_vpn,
requested_networks=requested_networks,
macs=macs,
security_groups=security_groups,
dhcp_options=dhcp_options)
... 最后通过network_api.allocate_for_instance()里执行操作。 allocate_for_instance()在/nova/network/neutronv2/api.py中：
def allocate_for_instance(self, context, instance, **kwargs):
...
if requested_networks:
for network_id, fixed_ip, port_id in requested_networks:
if port_id:
port = neutron.show_port(port_id)['port']
if port.get('device_id'):
raise exception.PortInUse(port_id=port_id)
if hypervisor_macs is not None:
if port['mac_address'] not in hypervisor_macs:
raise exception.PortNotUsable(port_id=port_id,
instance=instance['display_name'])
else:
available_macs.discard(port['mac_address'])
network_id = port['network_id']
ports[network_id] = port
elif fixed_ip and network_id:
fixed_ips[network_id] = fixed_ip
if network_id:
net_ids.append(network_id)
...
touched_port_ids = []
created_port_ids = []
for network in nets:
if (security_groups and not (
network['subnets']
and network.get('port_security_enabled', True))):
raise exception.SecurityGroupCannotBeApplied()
network_id = network['id']
zone = 'compute:%s' % instance['availability_zone']
port_req_body = {'port': {'device_id': instance['uuid'],
'device_owner': zone}}
try:
port = ports.get(network_id)
self._populate_neutron_extension_values(instance,
port_req_body)
# Requires admin creds to set port bindings
port_client = (neutron if not
self._has_port_binding_extension() else
neutronv2.get_client(context, admin=True))
if port:
port_client.update_port(port['id'], port_req_body)
touched_port_ids.append(port['id'])
else:
//创建port
created_port_ids.append(self._create_port(
port_client, instance, network_id,
port_req_body, fixed_ips.get(network_id),
security_group_ids, available_macs, dhcp_opts))
...
nw_info = self.get_instance_nw_info(context, instance, networks=nets)
return network_model.NetworkInfo([port for port in nw_info
if port['id'] in created_port_ids +
touched_port_ids])