Merge "Avoid raising NetworkInterfaceNotFound exception in DHCP agent logs"

neutron/agent/linux/ip_lib.py

@@ -509,6 +509,10 @@ class IpLinkCommand(IpDeviceCommandBase):
         return privileged.get_link_attributes(self.name,
                                               self._parent.namespace)
 
+    @property
+    def exists(self):
+        return privileged.interface_exists(self.name, self._parent.namespace)
+
 
 class IpAddrCommand(IpDeviceCommandBase):
     COMMAND = 'addr'
@@ -946,8 +950,8 @@ def ensure_device_is_ready(device_name, namespace=None):
     dev = IPDevice(device_name, namespace=namespace)
     try:
         # Ensure the device has a MAC address and is up, even if it is already
-        # up. If the device doesn't exist, a RuntimeError will be raised.
-        if not dev.link.address:
+        # up.
+        if not dev.link.exists or not dev.link.address:
             LOG.error("Device %s cannot be used as it has no MAC "
                       "address", device_name)
             return False

neutron/privileged/agent/linux/ip_lib.py

@@ -19,6 +19,7 @@ import socket
 
 from neutron_lib import constants
 from oslo_concurrency import lockutils
+from oslo_log import log as logging
 import pyroute2
 from pyroute2 import netlink
 from pyroute2.netlink import exceptions as netlink_exceptions
@@ -33,6 +34,8 @@ from neutron._i18n import _
 from neutron import privileged
 
 
+LOG = logging.getLogger(__name__)
+
 _IP_VERSION_FAMILY_MAP = {4: socket.AF_INET, 6: socket.AF_INET6}
 
 NETNS_RUN_DIR = '/var/run/netns'
@@ -251,11 +254,16 @@ def _translate_ip_device_exception(e, device=None, namespace=None):
                                              namespace=namespace)
 
 
-def get_link_id(device, namespace):
+def get_link_id(device, namespace, raise_exception=True):
     with get_iproute(namespace) as ip:
         link_id = ip.link_lookup(ifname=device)
     if not link_id or len(link_id) < 1:
-        raise NetworkInterfaceNotFound(device=device, namespace=namespace)
+        if raise_exception:
+            raise NetworkInterfaceNotFound(device=device, namespace=namespace)
+        else:
+            LOG.debug('Interface %(dev)s not found in namespace %(namespace)s',
+                      {'dev': device, 'namespace': namespace})
+            return None
     return link_id[0]
 
 
@@ -387,10 +395,8 @@ def delete_interface(ifname, namespace, **kwargs):
 @privileged.default.entrypoint
 def interface_exists(ifname, namespace):
     try:
-        idx = get_link_id(ifname, namespace)
+        idx = get_link_id(ifname, namespace, raise_exception=False)
         return bool(idx)
-    except NetworkInterfaceNotFound:
-        return False
     except OSError as e:
         if e.errno == errno.ENOENT:
             return False

neutron/tests/unit/agent/linux/test_ip_lib.py

@@ -937,15 +937,21 @@ class TestDeviceExists(base.BaseTestCase):
 
     def test_ensure_device_is_ready_no_link_address(self):
         with mock.patch.object(
-            priv_lib, 'get_link_attributes'
-        ) as get_link_attributes, mock.patch.object(
-            priv_lib, 'set_link_attribute'
-        ) as set_link_attribute:
+                priv_lib, 'get_link_attributes') as get_link_attributes, \
+                mock.patch.object(priv_lib, 'set_link_attribute') as \
+                set_link_attribute, \
+                mock.patch.object(priv_lib, 'interface_exists',
+                                  return_value=True):
             get_link_attributes.return_value = {}
             self.assertFalse(ip_lib.ensure_device_is_ready("lo"))
             get_link_attributes.assert_called_once_with("lo", None)
             set_link_attribute.assert_not_called()
 
+    def test_ensure_device_is_ready_no_device(self):
+        with mock.patch.object(priv_lib, 'interface_exists',
+                               return_value=False):
+            self.assertFalse(ip_lib.ensure_device_is_ready("lo"))
+
 
 class TestGetRoutingTable(base.BaseTestCase):
     ip_db_interfaces = {