Merge "Refactor checks for device existence"

diff --cc neutron/agent/l3/ha_router.py
Simple merge

diff --cc neutron/agent/l3/router_info.py
index 9b7443cad419cd1c67728aeff5689bcba3c70532,3f7684b8462f9eb08f18a1aff061399cf6bde8e8..c1336355e6e737855c03a5812d412ac3075d4261
--- 1/neutron/agent/l3/router_info.py
--- 2/neutron/agent/l3/router_info.py
+++ b/neutron/agent/l3/router_info.py
@@@ -418,16 -416,21 +416,15 @@@ class RouterInfo(object)
                  for ip in floating_ips]
  
      def _plug_external_gateway(self, ex_gw_port, interface_name, ns_name):
-         if not ip_lib.device_exists(interface_name, namespace=ns_name):
-             self.driver.plug(ex_gw_port['network_id'],
-                              ex_gw_port['id'],
-                              interface_name,
-                              ex_gw_port['mac_address'],
-                              bridge=self.agent_conf.external_network_bridge,
-                              namespace=ns_name,
-                              prefix=EXTERNAL_DEV_PREFIX)
+         self.driver.plug(ex_gw_port['network_id'],
+                          ex_gw_port['id'],
+                          interface_name,
+                          ex_gw_port['mac_address'],
+                          bridge=self.agent_conf.external_network_bridge,
+                          namespace=ns_name,
+                          prefix=EXTERNAL_DEV_PREFIX)
  
 -    def _external_gateway_added(self, ex_gw_port, interface_name,
 -                                ns_name, preserve_ips):
 -        self._plug_external_gateway(ex_gw_port, interface_name, ns_name)
 -
 -        # Build up the interface and gateway IP addresses that
 -        # will be added to the interface.
 -        ip_cidrs = common_utils.fixed_ip_cidrs(ex_gw_port['fixed_ips'])
 +    def _get_external_gw_ips(self, ex_gw_port):
          gateway_ips = []
          enable_ra_on_gw = False
          if 'subnets' in ex_gw_port:

diff --cc neutron/agent/linux/interface.py
Simple merge

diff --cc neutron/tests/unit/agent/l3/test_agent.py
Simple merge

diff --cc neutron/tests/unit/agent/linux/test_interface.py
Simple merge