Ignore gre0 and gretap0 devices in netns cleanup script.

This is tested by
http://git.openstack.org/cgit/openstack/neutron/tree/neutron/tests/functional/cmd/test_netns_cleanup.py?h=9.0.0#n49

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

Change-Id: I24ac257cafc7a2617215f1072509e70e40d23fea
Closes-Bug: #1631004
(cherry picked from commit 0e5caebd452518b6be9c99248187ddc9926818ce)

2 files changed, 18 insertions, 5 deletions

diff --git a/neutron/agent/linux/ip_lib.py b/neutron/agent/linux/ip_lib.py
index e8ca9eeea2..3c9d78f2a4 100644
--- a/neutron/agent/linux/ip_lib.py
+++ b/neutron/agent/linux/ip_lib.py
@@ -40,6 +40,7 @@ OPTS = [
 IP_NONLOCAL_BIND = 'net.ipv4.ip_nonlocal_bind'
 
 LOOPBACK_DEVNAME = 'lo'
+GRE_TUNNEL_DEVICE_NAMES = ['gre0', 'gretap0']
 
 SYS_NET_PATH = '/sys/class/net'
 DEFAULT_GW_PATTERN = re.compile(r"via (\S+)")
@@ -118,7 +119,7 @@ class IPWrapper(SubProcessBase):
     def device(self, name):
         return IPDevice(name, namespace=self.namespace)
 
-    def get_devices(self, exclude_loopback=False):
+    def get_devices(self, exclude_loopback=False, exclude_gre_devices=False):
         retval = []
         if self.namespace:
             # we call out manually because in order to avoid screen scraping
@@ -146,7 +147,8 @@ class IPWrapper(SubProcessBase):
             )
 
         for name in output:
-            if exclude_loopback and name == LOOPBACK_DEVNAME:
+            if (exclude_loopback and name == LOOPBACK_DEVNAME or
+                    exclude_gre_devices and name in GRE_TUNNEL_DEVICE_NAMES):
                 continue
             retval.append(IPDevice(name, namespace=self.namespace))
 
@@ -210,7 +212,8 @@ class IPWrapper(SubProcessBase):
         return ip
 
     def namespace_is_empty(self):
-        return not self.get_devices(exclude_loopback=True)
+        return not self.get_devices(exclude_loopback=True,
+                                    exclude_gre_devices=True)
 
     def garbage_collect_namespace(self):
         """Conditionally destroy the namespace if it is empty."""
diff --git a/neutron/tests/unit/agent/linux/test_ip_lib.py b/neutron/tests/unit/agent/linux/test_ip_lib.py
index 99e7901d48..aea037e6ef 100644
--- a/neutron/tests/unit/agent/linux/test_ip_lib.py
+++ b/neutron/tests/unit/agent/linux/test_ip_lib.py
@@ -282,6 +282,16 @@ class TestIpWrapper(base.BaseTestCase):
         self.assertEqual(retval, [ip_lib.IPDevice('lo', namespace='foo')])
 
     @mock.patch('neutron.agent.common.utils.execute')
+    def test_get_devices_exclude_loopback_and_gre(self, mocked_execute):
+        device_name = 'somedevice'
+        mocked_execute.return_value = 'lo gre0 gretap0 ' + device_name
+        devices = ip_lib.IPWrapper(namespace='foo').get_devices(
+            exclude_loopback=True, exclude_gre_devices=True)
+        somedevice = devices.pop()
+        self.assertEqual(device_name, somedevice.name)
+        self.assertFalse(devices)
+
+    @mock.patch('neutron.agent.common.utils.execute')
     def test_get_devices_namespaces_ns_not_exists(self, mocked_execute):
         mocked_execute.side_effect = RuntimeError(
             "Cannot open network namespace")
@@ -402,7 +412,7 @@ class TestIpWrapper(base.BaseTestCase):
             get_devices.return_value = []
 
             self.assertTrue(ip.namespace_is_empty())
-            get_devices.assert_called_once_with(exclude_loopback=True)
+            self.assertTrue(get_devices.called)
 
     def test_namespace_is_empty(self):
         ip = ip_lib.IPWrapper(namespace='ns')
@@ -410,7 +420,7 @@ class TestIpWrapper(base.BaseTestCase):
             get_devices.return_value = [mock.Mock()]
 
             self.assertFalse(ip.namespace_is_empty())
-            get_devices.assert_called_once_with(exclude_loopback=True)
+            self.assertTrue(get_devices.called)
 
     def test_garbage_collect_namespace_does_not_exist(self):
         with mock.patch.object(ip_lib, 'IpNetnsCommand') as ip_ns_cmd_cls: