Speed up openstack server listing

The old openstack driver used the "bare=True" argument to list_servers
and then relied on wait_for_server to expand the network information
on the server when it was active.  The new driver omits the bare
argument meaning that neutron is consulted for all server lists.

This can be very slow on large systems, so let's switch back to
bare=True, but instead of calling wait_for_server (which we are
unable to do in the state machine framework since state machine
runs are expected to be quick), we add the interface data ourselves
when refreshing information about active servers.

Change-Id: Ia7dce406e14b06166d5fa1d5d9bea0e661122dde

nodepool/driver/fake/adapter.py

@@ -444,3 +444,6 @@ class FakeAdapter(OpenStackAdapter):
             self.createServer_fails_with_external_id -= 1
             raise OpenStackCloudCreateException('server', 'fakeid')
         return super()._createServer(*args, **kwargs)
+
+    def _expandServer(self, server):
+        return server

nodepool/driver/openstack/adapter.py

@@ -627,21 +627,27 @@ class OpenStackAdapter(statemachine.Adapter):
 
     @cachetools.func.ttl_cache(maxsize=1, ttl=CACHE_TTL)
     def _listServers(self):
-        return self._client.list_servers()
+        return self._client.list_servers(bare=True)
 
     @cachetools.func.ttl_cache(maxsize=1, ttl=CACHE_TTL)
     def _listFloatingIps(self):
         return self._client.list_floating_ips()
 
     def _refreshServer(self, obj):
-        for server in self._listServers():
-            if server.id == obj.id:
-                return server
+        ret = self._getServer(obj.id)
+        if ret:
+            return ret
         return obj
 
+    def _expandServer(self, server):
+        return openstack.cloud.meta.add_server_interfaces(
+            self._client, server)
+
     def _getServer(self, external_id):
         for server in self._listServers():
             if server.id == external_id:
+                if server.status in ['ACTIVE', 'ERROR']:
+                    return self._expandServer(server)
                 return server
         return None