Merge LibvirtBridgeDriver class into LibvirtGenericVIFDriver

This introduces the LibvirtGenericVIFDriver class which uses
the 'vif_type' mapping field to determine what type of host
network configuration is required.

The LibvirtBridgeDriver class functionality is merged into
LibvirtGenericVIFDriver. For backwards compatibility with
the Folsom release, the existing LibvirtBridgeDriver class
is made to inherit from LibvirtGenericVIFDriver and directly
call the bridge specific setup APIs. This eases migration to
the new VIF impl during the Grizzly deployment lifecycle, with
an expectation that the LibvirtBridgeDriver stub will be
deleted in the Hxxxxx release.

DocImpact
Blueprint: libvirt-vif-driver
Change-Id: I948158b5ee0a97f666bb4d21020b552d3475b6d3
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

3 files changed, 132 insertions, 18 deletions

diff --git a/nova/tests/test_libvirt_vif.py b/nova/tests/test_libvirt_vif.py
index 3861d7dfa..7ce81cc09 100644
--- a/nova/tests/test_libvirt_vif.py
+++ b/nova/tests/test_libvirt_vif.py
@@ -16,6 +16,8 @@
 
 from lxml import etree
 
+from nova import exception
+from nova.network import model as network_model
 from nova.openstack.common import cfg
 from nova import test
 from nova import utils
@@ -48,7 +50,8 @@ class LibvirtVifTestCase(test.TestCase):
         'ips': [{'ip': '101.168.1.9'}],
         'dhcp_server': '191.168.1.1',
         'vif_uuid': 'vif-xxx-yyy-zzz',
-        'vif_devname': 'tap-xxx-yyy-zzz'
+        'vif_devname': 'tap-xxx-yyy-zzz',
+        'vif_type': network_model.VIF_TYPE_BRIDGE,
     }
 
     net_ovs = {
@@ -75,6 +78,15 @@ class LibvirtVifTestCase(test.TestCase):
         'ovs_interfaceid': 'aaa-bbb-ccc',
     }
 
+    mapping_none = {
+        'mac': 'ca:fe:de:ad:be:ef',
+        'gateway_v6': net_bridge['gateway_v6'],
+        'ips': [{'ip': '101.168.1.9'}],
+        'dhcp_server': '191.168.1.1',
+        'vif_uuid': 'vif-xxx-yyy-zzz',
+        'vif_devname': 'tap-xxx-yyy-zzz',
+    }
+
     instance = {
         'name': 'instance-name',
         'uuid': 'instance-uuid'
@@ -149,7 +161,7 @@ class LibvirtVifTestCase(test.TestCase):
         self.flags(libvirt_use_virtio_for_bridges=False,
                    libvirt_type='kvm')
 
-        d = vif.LibvirtBridgeDriver()
+        d = vif.LibvirtGenericVIFDriver()
         xml = self._get_instance_xml(d,
                                      self.net_bridge,
                                      self.mapping_bridge)
@@ -168,7 +180,7 @@ class LibvirtVifTestCase(test.TestCase):
         self.flags(libvirt_use_virtio_for_bridges=True,
                    libvirt_type='kvm')
 
-        d = vif.LibvirtBridgeDriver()
+        d = vif.LibvirtGenericVIFDriver()
         xml = self._get_instance_xml(d,
                                      self.net_bridge,
                                      self.mapping_bridge)
@@ -187,7 +199,7 @@ class LibvirtVifTestCase(test.TestCase):
         self.flags(libvirt_use_virtio_for_bridges=True,
                    libvirt_type='qemu')
 
-        d = vif.LibvirtBridgeDriver()
+        d = vif.LibvirtGenericVIFDriver()
         xml = self._get_instance_xml(d,
                                      self.net_bridge,
                                      self.mapping_bridge)
@@ -206,7 +218,7 @@ class LibvirtVifTestCase(test.TestCase):
         self.flags(libvirt_use_virtio_for_bridges=True,
                    libvirt_type='xen')
 
-        d = vif.LibvirtBridgeDriver()
+        d = vif.LibvirtGenericVIFDriver()
         xml = self._get_instance_xml(d,
                                      self.net_bridge,
                                      self.mapping_bridge)
@@ -221,8 +233,15 @@ class LibvirtVifTestCase(test.TestCase):
         ret = node.findall("driver")
         self.assertEqual(len(ret), 0)
 
-    def test_bridge_driver(self):
-        d = vif.LibvirtBridgeDriver()
+    def test_generic_driver_none(self):
+        d = vif.LibvirtGenericVIFDriver()
+        self.assertRaises(exception.NovaException,
+                          self._get_instance_xml,
+                          d,
+                          self.net_bridge,
+                          self.mapping_none)
+
+    def _check_bridge_driver(self, d):
         xml = self._get_instance_xml(d,
                                      self.net_bridge,
                                      self.mapping_bridge)
@@ -237,6 +256,14 @@ class LibvirtVifTestCase(test.TestCase):
         mac = node.find("mac").get("address")
         self.assertEqual(mac, self.mapping_bridge['mac'])
 
+    def test_bridge_driver(self):
+        d = vif.LibvirtBridgeDriver()
+        self._check_bridge_driver(d)
+
+    def test_generic_driver_bridge(self):
+        d = vif.LibvirtGenericVIFDriver()
+        self._check_bridge_driver(d)
+
     def test_ovs_ethernet_driver(self):
         d = vif.LibvirtOpenVswitchDriver()
         xml = self._get_instance_xml(d,
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 7439ad40a..9e6d7350d 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -140,7 +140,7 @@ libvirt_opts = [
                     'raw, qcow2, vmdk, vdi). '
                     'Defaults to same as source image'),
     cfg.StrOpt('libvirt_vif_driver',
-               default='nova.virt.libvirt.vif.LibvirtBridgeDriver',
+               default='nova.virt.libvirt.vif.LibvirtGenericVIFDriver',
                help='The libvirt VIF driver to configure the VIFs.'),
     cfg.ListOpt('libvirt_volume_drivers',
                 default=[
diff --git a/nova/virt/libvirt/vif.py b/nova/virt/libvirt/vif.py
index d90a5e295..f185e8efd 100644
--- a/nova/virt/libvirt/vif.py
+++ b/nova/virt/libvirt/vif.py
@@ -72,19 +72,22 @@ class LibvirtBaseVIFDriver(object):
 
         return conf
 
+    def plug(self, instance, vif):
+        pass
+
+    def unplug(self, instance, vif):
+        pass
+
 
-class LibvirtBridgeDriver(LibvirtBaseVIFDriver):
-    """VIF driver for Linux bridge."""
+class LibvirtGenericVIFDriver(LibvirtBaseVIFDriver):
+    """Generic VIF driver for libvirt networking."""
 
     def get_bridge_name(self, network):
         return network['bridge']
 
-    def get_config(self, instance, network, mapping):
+    def get_config_bridge(self, instance, network, mapping):
         """Get VIF configurations for bridge type."""
-
-        mac_id = mapping['mac'].replace(':', '')
-
-        conf = super(LibvirtBridgeDriver,
+        conf = super(LibvirtGenericVIFDriver,
                      self).get_config(instance,
                                       network,
                                       mapping)
@@ -93,6 +96,7 @@ class LibvirtBridgeDriver(LibvirtBaseVIFDriver):
             conf, self.get_bridge_name(network),
             self.get_vif_devname(mapping))
 
+        mac_id = mapping['mac'].replace(':', '')
         name = "nova-instance-" + instance['name'] + "-" + mac_id
         primary_addr = mapping['ips'][0]['ip']
         dhcp_server = ra_server = ipv4_cidr = ipv6_cidr = None
@@ -112,8 +116,29 @@ class LibvirtBridgeDriver(LibvirtBaseVIFDriver):
 
         return conf
 
-    def plug(self, instance, vif):
+    def get_config(self, instance, network, mapping):
+        vif_type = mapping.get('vif_type')
+
+        LOG.debug(_("vif_type=%(vif_type)s instance=%(instance)s "
+                    "network=%(network)s mapping=%(mapping)s")
+                  % locals())
+
+        if vif_type is None:
+            raise exception.NovaException(
+                _("vif_type parameter must be present "
+                  "for this vif_driver implementation"))
+
+        if vif_type == network_model.VIF_TYPE_BRIDGE:
+            return self.get_config_bridge(instance, network, mapping)
+        else:
+            raise exception.NovaException(
+                _("Unexpected vif_type=%s") % vif_type)
+
+    def plug_bridge(self, instance, vif):
         """Ensure that the bridge exists, and add VIF to it."""
+        super(LibvirtGenericVIFDriver,
+              self).plug(instance, vif)
+
         network, mapping = vif
         if (not network.get('multi_host') and
             mapping.get('should_create_bridge')):
@@ -135,9 +160,71 @@ class LibvirtBridgeDriver(LibvirtBaseVIFDriver):
                                         self.get_bridge_name(network),
                                         iface)
 
-    def unplug(self, instance, vif):
+    def plug(self, instance, vif):
+        network, mapping = vif
+        vif_type = mapping.get('vif_type')
+
+        LOG.debug(_("vif_type=%(vif_type)s instance=%(instance)s "
+                    "network=%(network)s mapping=%(mapping)s")
+                  % locals())
+
+        if vif_type is None:
+            raise exception.NovaException(
+                _("vif_type parameter must be present "
+                  "for this vif_driver implementation"))
+
+        if vif_type == network_model.VIF_TYPE_BRIDGE:
+            self.plug_bridge(instance, vif)
+        else:
+            raise exception.NovaException(
+                _("Unexpected vif_type=%s") % vif_type)
+
+    def unplug_bridge(self, instance, vif):
         """No manual unplugging required."""
-        pass
+        super(LibvirtGenericVIFDriver,
+              self).unplug(instance, vif)
+
+    def unplug(self, instance, vif):
+        network, mapping = vif
+        vif_type = mapping.get('vif_type')
+
+        LOG.debug(_("vif_type=%(vif_type)s instance=%(instance)s "
+                    "network=%(network)s mapping=%(mapping)s")
+                  % locals())
+
+        if vif_type is None:
+            raise exception.NovaException(
+                _("vif_type parameter must be present "
+                  "for this vif_driver implementation"))
+
+        if vif_type == network_model.VIF_TYPE_BRIDGE:
+            self.unplug_bridge(instance, vif)
+        else:
+            raise exception.NovaException(
+                _("Unexpected vif_type=%s") % vif_type)
+
+
+class LibvirtBridgeDriver(LibvirtGenericVIFDriver):
+    """Deprecated in favour of LibvirtGenericVIFDriver.
+       Retained in Grizzly for compatibility with Quantum
+       drivers which do not yet report 'vif_type' port binding.
+       To be removed in Hxxxx."""
+
+    def __init__(self):
+        LOG.deprecated(
+            _("LibvirtBridgeDriver is deprecated and "
+              "will be removed in the Hxxxx release. Please "
+              "update the 'libvirt_vif_driver' config parameter "
+              "to use the LibvirtGenericVIFDriver class instead"))
+
+    def get_config(self, instance, network, mapping):
+        return self.get_config_bridge(instance, network, mapping)
+
+    def plug(self, instance, vif):
+        self.plug_bridge(instance, vif)
+
+    def unplug(self, instance, vif):
+        self.unplug_bridge(instance, vif)
 
 
 class LibvirtOpenVswitchDriver(LibvirtBaseVIFDriver):