neutron: Rework how we check for extensions

There are couple of changes we can make here:

- Always attempt to refresh the cache before checking if an extension is
  enabled.
- Using extension slugs as our reference point rather than extension
  names. They seem like a better thing to use as a constant and are
  similarly fixed.
- Be consistent in how we name and call the extension check functions
- Add documentation for what each extension doing/used for

There's a TODO here to remove some code that relies on an out-of-tree
extension that I can't see. That's done separately since this is already
big enough.

Change-Id: I8058902df167239fa455396d3595a56bcf472b2b
Signed-off-by: Stephen Finucane <[email protected]>

Author: stephenfin

nova/compute/manager.py

@@ -8039,7 +8039,7 @@ def check_can_live_migrate_destination(self, ctxt, instance,
                 LOG.info('Destination was ready for NUMA live migration, '
                          'but source is either too old, or is set to an '
                          'older upgrade level.', instance=instance)
-            if self.network_api.supports_port_binding_extension(ctxt):
+            if self.network_api.has_port_binding_extension(ctxt):
                 # Create migrate_data vifs if not provided by driver.
                 if 'vifs' not in migrate_data:
                     migrate_data.vifs = (

nova/conductor/tasks/cross_cell_migrate.py

@@ -697,7 +697,7 @@ def _perform_external_api_checks(self):
         LOG.debug('Making sure neutron is new enough for cross-cell resize.')
         # Check that the port binding-extended API extension is available in
         # neutron because if it's not we can just fail fast.
-        if not self.network_api.supports_port_binding_extension(self.context):
+        if not self.network_api.has_port_binding_extension(self.context):
             raise exception.MigrationPreCheckError(
                 reason=_("Required networking service API extension '%s' "
                          "not found.") %

nova/conductor/tasks/live_migrate.py

@@ -245,8 +245,7 @@ def _check_can_migrate_pci(self, src_host, dest_host):
                             "are not allowed for live migration.")
         # All PCI requests are VIF related, now check neutron,
         # source and destination compute nodes.
-        if not self.network_api.supports_port_binding_extension(
-                self.context):
+        if not self.network_api.has_port_binding_extension(self.context):
             raise exception.MigrationPreCheckError(
                 reason="Cannot live migrate VIF with related PCI, Neutron "
                        "does not support required port binding extension.")
@@ -366,7 +365,7 @@ def _call_livem_checks_on_host(self, destination, provider_mapping):
             raise exception.MigrationPreCheckError(msg)
 
         # Check to see that neutron supports the binding-extended API.
-        if self.network_api.supports_port_binding_extension(self.context):
+        if self.network_api.has_port_binding_extension(self.context):
             bindings = self._bind_ports_on_destination(
                 destination, provider_mapping)
             self._update_migrate_vifs_from_bindings(self.migrate_data.vifs,

nova/network/constants.py

@@ -13,23 +13,40 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-QOS_QUEUE = 'QoS Queue'
-NET_EXTERNAL = 'router:external'
-VNIC_INDEX_EXT = 'VNIC Index'
-DNS_INTEGRATION = 'DNS Integration'
-MULTI_NET_EXT = 'Multi Provider Network'
-FIP_PORT_DETAILS = 'Floating IP Port Details Extension'
-SUBSTR_PORT_FILTERING = 'IP address substring filtering'
-PORT_BINDING = 'Port Binding'
-PORT_BINDING_EXTENDED = 'Port Bindings Extended'
-DEFAULT_SECGROUP = 'default'
+# Port fields
+
 BINDING_PROFILE = 'binding:profile'
 BINDING_HOST_ID = 'binding:host_id'
-MIGRATING_ATTR = 'migrating_to'
-L3_NETWORK_TYPES = ['vxlan', 'gre', 'geneve']
-ALLOCATION = 'allocation'
 RESOURCE_REQUEST = 'resource_request'
 REQUEST_GROUPS = 'request_groups'
-SEGMENT = 'Segment'
 NUMA_POLICY = 'numa_affinity_policy'
-RESOURCE_REQUEST_GROUPS_EXTENSION = "Port Resource Request Groups"
+
+# Binding profile fields
+
+MIGRATING_ATTR = 'migrating_to'
+ALLOCATION = 'allocation'
+
+# Core extensions
+
+DNS_INTEGRATION = 'dns-integration'
+MULTI_PROVIDER = 'multi-provider'
+FIP_PORT_DETAILS = 'fip-port-details'
+PORT_BINDING = 'binding'
+PORT_BINDING_EXTENDED = 'binding-extended'
+SUBSTR_PORT_FILTERING = 'ip-substring-filtering'
+SEGMENT = 'segment'
+RESOURCE_REQUEST_GROUPS = 'port-resource-request-groups'
+
+# Third-party extensions
+
+VNIC_INDEX = 'vnic-index'  # this is provided by the vmware_nsx project
+QOS_QUEUE = 'qos-queue'  # TODO(stephenfin): what defines this? Xen?
+
+# Search fields
+
+NET_EXTERNAL = 'router:external'
+
+# Misc
+
+DEFAULT_SECGROUP = 'default'
+L3_NETWORK_TYPES = ['vxlan', 'gre', 'geneve']