Default route missing for IPv6 subnets in HA Router

In an HA setup, keepalived would configure the default gateway (in the master
HA router) by parsing the "virtual_routes" section of keepalived.conf file.
The "virtual_routes" section is properly constructed for an IPv4 subnet, but
requires a minor change for IPv6 subnets.

Closes-Bug: #1414937
Change-Id: I54070e048577292d98d86fcc9ca8b9d3e72b4ebe

neutron/agent/l3/ha_router.py

@@ -174,8 +174,9 @@ class HaRouter(router.RouterInfo):
         instance = self._get_keepalived_instance()
 
         # Filter out all of the old routes while keeping only the default route
+        default_gw = ('::/0', '0.0.0.0/0')
         instance.virtual_routes = [route for route in instance.virtual_routes
-                                   if route.destination == '0.0.0.0/0']
+                                   if route.destination in default_gw]
         for route in new_routes:
             instance.virtual_routes.append(keepalived.KeepalivedVirtualRoute(
                 route['destination'],
@@ -187,13 +188,15 @@ class HaRouter(router.RouterInfo):
         gw_ip = ex_gw_port['subnet']['gateway_ip']
         if gw_ip:
             # TODO(Carl) This is repeated everywhere.  A method would be nice.
+            default_gw = ('0.0.0.0/0' if netaddr.IPAddress(gw_ip).version == 4
+                          else '::/0')
             instance = self._get_keepalived_instance()
             instance.virtual_routes = (
                 [route for route in instance.virtual_routes
-                 if route.destination != '0.0.0.0/0'])
+                 if route.destination != default_gw])
             instance.virtual_routes.append(
                 keepalived.KeepalivedVirtualRoute(
-                    '0.0.0.0/0', gw_ip, interface_name))
+                    default_gw, gw_ip, interface_name))
 
     def _get_ipv6_lladdr(self, mac_addr):
         return '%s/64' % netaddr.EUI(mac_addr).ipv6_link_local()

neutron/tests/functional/agent/test_l3_agent.py

@@ -99,11 +99,18 @@ class L3AgentTestFramework(base.BaseOVSLinuxTestCase):
 
         return agent
 
-    def generate_router_info(self, enable_ha):
-        return test_l3_agent.prepare_router_data(enable_snat=True,
-                                                 enable_floating_ip=True,
+    def generate_router_info(self, enable_ha, ip_version=4, extra_routes=True,
+                             enable_fip=True, enable_snat=True):
+        if ip_version == 6:
+            enable_snat = False
+            enable_fip = False
+            extra_routes = False
+
+        return test_l3_agent.prepare_router_data(ip_version=ip_version,
+                                                 enable_snat=enable_snat,
+                                                 enable_floating_ip=enable_fip,
                                                  enable_ha=enable_ha,
-                                                 extra_routes=True)
+                                                 extra_routes=extra_routes)
 
     def manage_router(self, agent, router):
         self.addCleanup(self._delete_router, agent, router['id'])
@@ -341,6 +348,9 @@ class L3AgentTestCase(L3AgentTestFramework):
             with testtools.ExpectedException(RuntimeError):
                 netcat.test_connectivity()
 
+    def test_ipv6_ha_router_lifecycle(self):
+        self._router_lifecycle(enable_ha=True, ip_version=6)
+
     def test_keepalived_configuration(self):
         router_info = self.generate_router_info(enable_ha=True)
         router = self.manage_router(self.agent, router_info)
@@ -380,8 +390,8 @@ class L3AgentTestCase(L3AgentTestFramework):
                       (new_external_device_ip, external_device_name),
                       new_config)
 
-    def _router_lifecycle(self, enable_ha):
-        router_info = self.generate_router_info(enable_ha)
+    def _router_lifecycle(self, enable_ha, ip_version=4):
+        router_info = self.generate_router_info(enable_ha, ip_version)
         router = self.manage_router(self.agent, router_info)
 
         if enable_ha:
@@ -406,12 +416,17 @@ class L3AgentTestCase(L3AgentTestFramework):
         self.assertTrue(self._metadata_proxy_exists(self.agent.conf, router))
         self._assert_internal_devices(router)
         self._assert_external_device(router)
-        self._assert_gateway(router)
-        self.assertTrue(self._floating_ips_configured(router))
-        self._assert_snat_chains(router)
-        self._assert_floating_ip_chains(router)
+        if ip_version == 4:
+            # Note(SridharG): enable the assert_gateway for IPv6 once
+            # keepalived on Ubuntu14.04 (i.e., check-neutron-dsvm-functional
+            # platform) is updated to 1.2.10 (or above).
+            # For more details: https://review.openstack.org/#/c/151284/
+            self._assert_gateway(router)
+            self.assertTrue(self._floating_ips_configured(router))
+            self._assert_snat_chains(router)
+            self._assert_floating_ip_chains(router)
+            self._assert_extra_routes(router)
         self._assert_metadata_chains(router)
-        self._assert_extra_routes(router)
 
         if enable_ha:
             self._assert_ha_device(router)

neutron/tests/unit/test_l3_agent.py

@@ -64,9 +64,9 @@ def router_append_interface(router, count=1, ip_version=4, ra_mode=None,
         cidr_pool = '35.4.%i.0/24'
         gw_pool = '35.4.%i.1'
     elif ip_version == 6:
-        ip_pool = 'fd01:%x::6'
-        cidr_pool = 'fd01:%x::/64'
-        gw_pool = 'fd01:%x::1'
+        ip_pool = 'fd01:%x:1::6'
+        cidr_pool = 'fd01:%x:1::/64'
+        gw_pool = 'fd01:%x:1::1'
     else:
         raise ValueError("Invalid ip_version: %s" % ip_version)