Add flush command to iproute in ip_lib

IP route flush command to support flush the route
entries.

Closes-Bug: #1611513
(cherry picked from commit 87488f345c47d587e432206b2f7289a727e7e528)

Conflicts:
	neutron/agent/linux/ip_lib.py
	neutron/tests/unit/agent/linux/test_ip_lib.py
Change-Id: I401b242cc86ba1de7a20943d8b0340e0f0005ba3

2 files changed, 11 insertions, 0 deletions

diff --git a/neutron/agent/linux/ip_lib.py b/neutron/agent/linux/ip_lib.py
index 7d7962366b..115686f0d4 100644
--- a/neutron/agent/linux/ip_lib.py
+++ b/neutron/agent/linux/ip_lib.py
@@ -800,6 +800,13 @@ class IpRouteCommand(IpDeviceCommandBase):
                                    'proto', 'kernel',
                                    'dev', device))
 
+    def flush(self, ip_version, table=None, **kwargs):
+        args = ['flush']
+        args += self._table_args(table)
+        for k, v in kwargs.items():
+            args += [k, v]
+        self._as_root([ip_version], tuple(args))
+
     def add_route(self, cidr, via=None, table=None, **kwargs):
         ip_version = get_ip_version(cidr)
         args = ['replace', cidr]
diff --git a/neutron/tests/unit/agent/linux/test_ip_lib.py b/neutron/tests/unit/agent/linux/test_ip_lib.py
index 3e1d351d42..a33f36e5f7 100644
--- a/neutron/tests/unit/agent/linux/test_ip_lib.py
+++ b/neutron/tests/unit/agent/linux/test_ip_lib.py
@@ -982,6 +982,10 @@ class TestIpRouteCommand(TestIPCmdBase):
         # Check two calls - device get and subnet get
         self.assertEqual(len(self.parent._run.mock_calls), 2)
 
+    def test_flush_route_table(self):
+        self.route_cmd.flush(self.ip_version, self.table)
+        self._assert_sudo([self.ip_version], ('flush', 'table', self.table))
+
     def test_add_route(self):
         self.route_cmd.add_route(self.cidr, self.ip, self.table)
         self._assert_sudo([self.ip_version],