Remove network_util.NetworkHelper class

The XenAPI driver has the concept of helper classes. All methods
have been classmethods and the classes themselves are never
instantiated. As a result, they only add an extra namespace
lookup and provide no value.

Change-Id: Ief7d51013d8f313ca8c78cb157599858b156ac3f

3 files changed, 27 insertions, 37 deletions

diff --git a/nova/virt/xenapi/network_utils.py b/nova/virt/xenapi/network_utils.py
index 50b36933c..dceaed949 100644
--- a/nova/virt/xenapi/network_utils.py
+++ b/nova/virt/xenapi/network_utils.py
@@ -21,38 +21,29 @@ their lookup functions.
 """
 
 
-from nova.virt import xenapi
+def find_network_with_name_label(session, name_label):
+    networks = session.call_xenapi('network.get_by_name_label', name_label)
+    if len(networks) == 1:
+        return networks[0]
+    elif len(networks) > 1:
+        raise Exception(_('Found non-unique network for name_label %s') %
+                        name_label)
+    else:
+        return None
 
 
-class NetworkHelper(xenapi.HelperBase):
+def find_network_with_bridge(session, bridge):
     """
-    The class that wraps the helper methods together.
+    Return the network on which the bridge is attached, if found.
+    The bridge is defined in the nova db and can be found either in the
+    'bridge' or 'name_label' fields of the XenAPI network record.
     """
-    @classmethod
-    def find_network_with_name_label(cls, session, name_label):
-        networks = session.call_xenapi('network.get_by_name_label', name_label)
-        if len(networks) == 1:
-            return networks[0]
-        elif len(networks) > 1:
-            raise Exception(_('Found non-unique network'
-                              ' for name_label %s') % name_label)
-        else:
-            return None
-
-    @classmethod
-    def find_network_with_bridge(cls, session, bridge):
-        """
-        Return the network on which the bridge is attached, if found.
-        The bridge is defined in the nova db and can be found either in the
-        'bridge' or 'name_label' fields of the XenAPI network record.
-        """
-        expr = ('field "name__label" = "%s" or field "bridge" = "%s"' %
-                (bridge, bridge))
-        networks = session.call_xenapi('network.get_all_records_where', expr)
-        if len(networks) == 1:
-            return networks.keys()[0]
-        elif len(networks) > 1:
-            raise Exception(_('Found non-unique network'
-                              ' for bridge %s') % bridge)
-        else:
-            raise Exception(_('Found no network for bridge %s') % bridge)
+    expr = ('field "name__label" = "%s" or field "bridge" = "%s"' %
+            (bridge, bridge))
+    networks = session.call_xenapi('network.get_all_records_where', expr)
+    if len(networks) == 1:
+        return networks.keys()[0]
+    elif len(networks) > 1:
+        raise Exception(_('Found non-unique network for bridge %s') % bridge)
+    else:
+        raise Exception(_('Found no network for bridge %s') % bridge)
diff --git a/nova/virt/xenapi/vif.py b/nova/virt/xenapi/vif.py
index c2885cc4d..39778521b 100644
--- a/nova/virt/xenapi/vif.py
+++ b/nova/virt/xenapi/vif.py
@@ -53,8 +53,8 @@ class XenAPIBridgeDriver(XenVIFDriver):
         if vif['network'].get_meta('should_create_vlan'):
             network_ref = self._ensure_vlan_bridge(vif['network'])
         else:
-            network_ref = network_utils.NetworkHelper.find_network_with_bridge(
-                                       self._session, vif['network']['bridge'])
+            network_ref = network_utils.find_network_with_bridge(
+                    self._session, vif['network']['bridge'])
         vif_rec = {}
         vif_rec['device'] = str(device)
         vif_rec['network'] = network_ref
@@ -80,7 +80,7 @@ class XenAPIBridgeDriver(XenVIFDriver):
                             network.get_meta('bridge_interface'))
         # Check whether bridge already exists
         # Retrieve network whose name_label is "bridge"
-        network_ref = network_utils.NetworkHelper.find_network_with_name_label(
+        network_ref = network_utils.find_network_with_name_label(
                                         self._session, bridge)
         if network_ref is None:
             # If bridge does not exists
@@ -143,8 +143,8 @@ class XenAPIOpenVswitchDriver(XenVIFDriver):
 
         # with OVS model, always plug into an OVS integration bridge
         # that is already created
-        network_ref = network_utils.NetworkHelper.find_network_with_bridge(
-            self._session, FLAGS.xenapi_ovs_integration_bridge)
+        network_ref = network_utils.find_network_with_bridge(
+                self._session, FLAGS.xenapi_ovs_integration_bridge)
         vif_rec = {}
         vif_rec['device'] = str(device)
         vif_rec['network'] = network_ref
diff --git a/nova/virt/xenapi/vmops.py b/nova/virt/xenapi/vmops.py
index 031668d29..c79f09026 100644
--- a/nova/virt/xenapi/vmops.py
+++ b/nova/virt/xenapi/vmops.py
@@ -49,7 +49,6 @@ from nova.virt.xenapi import vm_utils
 from nova.virt.xenapi import volume_utils
 
 
-NetworkHelper = network_utils.NetworkHelper
 LOG = logging.getLogger(__name__)
 
 xenapi_vmops_opts = [