Add 'devname' to nova.network.model.VIF class

Add a 'devname' field to nova.network.model.VIF to allow network
drivers to specify a desired TAP device name. Update the Quantum
driver to set a device name, and update the libvirt VIF drivers
to honour it.

Blueprint: libvirt-vif-driver
Change-Id: Ia8dd546af36e7f6c22efd7c696fb58b37aac0061
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

6 files changed, 37 insertions, 29 deletions

diff --git a/nova/network/model.py b/nova/network/model.py
index f0a5d9d89..e4fe0d54c 100644
--- a/nova/network/model.py
+++ b/nova/network/model.py
@@ -32,9 +32,10 @@ VIF_TYPE_802_QBG = '802.1qbg'
 VIF_TYPE_802_QBH = '802.1qbh'
 VIF_TYPE_OTHER = 'other'
 
-# Constant for max length of 'bridge' in Network class
-# Chosen to match max Linux NIC name length
-BRIDGE_NAME_LEN = 14
+# Constant for max length of network interface names
+# eg 'bridge' in the Network class or 'devname' in
+# the VIF class
+NIC_NAME_LEN = 14
 
 
 class Model(dict):
@@ -206,13 +207,14 @@ class Network(Model):
 class VIF(Model):
     """Represents a Virtual Interface in Nova."""
     def __init__(self, id=None, address=None, network=None, type=None,
-                 **kwargs):
+                 devname=None, **kwargs):
         super(VIF, self).__init__()
 
         self['id'] = id
         self['address'] = address
         self['network'] = network or None
         self['type'] = type
+        self['devname'] = devname
 
         self._set_meta(kwargs)
 
@@ -377,6 +379,7 @@ class NetworkInfo(list):
                          'broadcast': str(subnet_v4.as_netaddr().broadcast),
                          'mac': vif['address'],
                          'vif_type': vif['type'],
+                         'vif_devname': vif.get('devname'),
                          'vif_uuid': vif['id'],
                          'rxtx_cap': vif.get_meta('rxtx_cap', 0),
                          'dns': [get_ip(ip) for ip in subnet_v4['dns']],
diff --git a/nova/network/quantumv2/api.py b/nova/network/quantumv2/api.py
index 780952bab..8347ee94d 100644
--- a/nova/network/quantumv2/api.py
+++ b/nova/network/quantumv2/api.py
@@ -593,7 +593,10 @@ class API(base.Base):
                 bridge = "brq" + port['network_id']
 
             if bridge is not None:
-                bridge = bridge[:network_model.BRIDGE_NAME_LEN]
+                bridge = bridge[:network_model.NIC_NAME_LEN]
+
+            devname = "tap" + port['id']
+            devname = devname[:network_model.NIC_NAME_LEN]
 
             network = network_model.Network(
                 id=port['network_id'],
@@ -607,7 +610,8 @@ class API(base.Base):
                 id=port['id'],
                 address=port['mac_address'],
                 network=network,
-                type=port.get('binding:vif_type')))
+                type=port.get('binding:vif_type'),
+                devname=devname))
         return nw_info
 
     def _get_subnets_from_port(self, context, port):
diff --git a/nova/tests/network/test_manager.py b/nova/tests/network/test_manager.py
index 385aea1ee..1552630fb 100644
--- a/nova/tests/network/test_manager.py
+++ b/nova/tests/network/test_manager.py
@@ -186,6 +186,7 @@ class FlatNetworkTestCase(test.TestCase):
                      'mac': 'DE:AD:BE:EF:00:%02x' % nid,
                      'rxtx_cap': 30,
                      'vif_type': net_model.VIF_TYPE_BRIDGE,
+                     'vif_devname': None,
                      'vif_uuid':
                         '00000000-0000-0000-0000-00000000000000%02d' % nid,
                      'should_create_vlan': False,
diff --git a/nova/tests/test_libvirt_vif.py b/nova/tests/test_libvirt_vif.py
index 9271afb13..11ffa020f 100644
--- a/nova/tests/test_libvirt_vif.py
+++ b/nova/tests/test_libvirt_vif.py
@@ -47,7 +47,8 @@ class LibvirtVifTestCase(test.TestCase):
         'gateway_v6': net['gateway_v6'],
         'ips': [{'ip': '101.168.1.9'}],
         'dhcp_server': '191.168.1.1',
-        'vif_uuid': 'vif-xxx-yyy-zzz'
+        'vif_uuid': 'vif-xxx-yyy-zzz',
+        'vif_devname': 'tap-xxx-yyy-zzz'
     }
 
     instance = {
diff --git a/nova/tests/utils.py b/nova/tests/utils.py
index 00b70ceb3..6437f9537 100644
--- a/nova/tests/utils.py
+++ b/nova/tests/utils.py
@@ -20,6 +20,7 @@ import nova.context
 import nova.db
 from nova.image import glance
 from nova.network import minidns
+from nova.network import model as network_model
 from nova.openstack.common import cfg
 
 CONF = cfg.CONF
@@ -91,6 +92,8 @@ def get_test_network_info(count=1):
                'bridge_interface': fake_bridge_interface,
                'injected': False}
     mapping = {'mac': fake,
+               'vif_type': network_model.VIF_TYPE_BRIDGE,
+               'vif_uuid': 'vif-xxx-yyy-zzz',
                'dhcp_server': fake,
                'dns': ['fake1', 'fake2'],
                'gateway': fake,
diff --git a/nova/virt/libvirt/vif.py b/nova/virt/libvirt/vif.py
index 29bf2d09d..54de9da2d 100644
--- a/nova/virt/libvirt/vif.py
+++ b/nova/virt/libvirt/vif.py
@@ -21,6 +21,7 @@
 
 from nova import exception
 from nova.network import linux_net
+from nova.network import model as network_model
 from nova.openstack.common import cfg
 from nova.openstack.common import log as logging
 from nova import utils
@@ -41,11 +42,14 @@ CONF.register_opts(libvirt_vif_opts)
 CONF.import_opt('libvirt_type', 'nova.virt.libvirt.driver')
 CONF.import_opt('use_ipv6', 'nova.netconf')
 
-LINUX_DEV_LEN = 14
-
 
 class LibvirtBaseVIFDriver(object):
 
+    def get_vif_devname(self, mapping):
+        if 'vif_devname' in mapping:
+            return mapping['vif_devname']
+        return ("nic" + mapping['vif_uuid'])[:network_model.NIC_NAME_LEN]
+
     def get_config(self, instance, network, mapping):
         conf = vconfig.LibvirtConfigGuestInterface()
         model = None
@@ -78,7 +82,7 @@ class LibvirtBridgeDriver(LibvirtBaseVIFDriver):
                                       mapping)
 
         designer.set_vif_host_backend_bridge_config(
-            conf, network['bridge'], None)
+            conf, network['bridge'], self.get_vif_devname(mapping))
 
         name = "nova-instance-" + instance['name'] + "-" + mac_id
         primary_addr = mapping['ips'][0]['ip']
@@ -134,11 +138,8 @@ class LibvirtOpenVswitchDriver(LibvirtBaseVIFDriver):
     OVS virtual port XML (0.9.10 or earlier).
     """
 
-    def get_dev_name(self, iface_id):
-        return ("tap" + iface_id)[:LINUX_DEV_LEN]
-
     def get_config(self, instance, network, mapping):
-        dev = self.get_dev_name(mapping['vif_uuid'])
+        dev = self.get_vif_devname(mapping)
 
         conf = super(LibvirtOpenVswitchDriver,
                      self).get_config(instance,
@@ -167,7 +168,7 @@ class LibvirtOpenVswitchDriver(LibvirtBaseVIFDriver):
     def plug(self, instance, vif):
         network, mapping = vif
         iface_id = mapping['vif_uuid']
-        dev = self.get_dev_name(iface_id)
+        dev = self.get_vif_devname(mapping)
         if not linux_net.device_exists(dev):
             # Older version of the command 'ip' from the iproute2 package
             # don't have support for the tuntap option (lp:882568).  If it
@@ -191,7 +192,7 @@ class LibvirtOpenVswitchDriver(LibvirtBaseVIFDriver):
         try:
             network, mapping = vif
             self.delete_ovs_vif_port(network['bridge'],
-                                     self.get_dev_name(mapping['vif_uuid']))
+                                     self.get_vif_devname(mapping))
         except exception.ProcessExecutionError:
             LOG.exception(_("Failed while unplugging vif"), instance=instance)
 
@@ -207,11 +208,11 @@ class LibvirtHybridOVSBridgeDriver(LibvirtBridgeDriver,
     """
 
     def get_br_name(self, iface_id):
-        return ("qbr" + iface_id)[:LINUX_DEV_LEN]
+        return ("qbr" + iface_id)[:network_model.NIC_NAME_LEN]
 
     def get_veth_pair_names(self, iface_id):
-        return (("qvb%s" % iface_id)[:LINUX_DEV_LEN],
-                ("qvo%s" % iface_id)[:LINUX_DEV_LEN])
+        return (("qvb%s" % iface_id)[:network_model.NIC_NAME_LEN],
+                ("qvo%s" % iface_id)[:network_model.NIC_NAME_LEN])
 
     def get_config(self, instance, network, mapping):
         br_name = self.get_br_name(mapping['vif_uuid'])
@@ -280,7 +281,8 @@ class LibvirtOpenVswitchVirtualPortDriver(LibvirtBaseVIFDriver):
                                       mapping)
 
         designer.set_vif_host_backend_ovs_config(
-            conf, network['bridge'], mapping['vif_uuid'])
+            conf, network['bridge'], mapping['vif_uuid'],
+            self.get_vif_devname(mapping))
 
         return conf
 
@@ -295,15 +297,9 @@ class LibvirtOpenVswitchVirtualPortDriver(LibvirtBaseVIFDriver):
 class QuantumLinuxBridgeVIFDriver(LibvirtBaseVIFDriver):
     """VIF driver for Linux Bridge when running Quantum."""
 
-    def get_dev_name(self, iface_id):
-        return ("tap" + iface_id)[:LINUX_DEV_LEN]
-
     def get_config(self, instance, network, mapping):
-        iface_id = mapping['vif_uuid']
-        dev = self.get_dev_name(iface_id)
-
-        bridge = network['bridge']
-        linux_net.LinuxBridgeInterfaceDriver.ensure_bridge(bridge, None,
+        linux_net.LinuxBridgeInterfaceDriver.ensure_bridge(network['bridge'],
+                                                           None,
                                                            filtering=False)
 
         conf = super(QuantumLinuxBridgeVIFDriver,
@@ -312,7 +308,7 @@ class QuantumLinuxBridgeVIFDriver(LibvirtBaseVIFDriver):
                                       mapping)
 
         designer.set_vif_host_backend_bridge_config(
-            conf, bridge, dev)
+            conf, network['bridge'], self.get_vif_devname(mapping))
 
         return conf