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.

Conflicts:
    neutron/agent/l3_ha_agent.py
    neutron/tests/functional/agent/test_l3_agent.py

Closes-Bug: #1414937
Change-Id: I54070e048577292d98d86fcc9ca8b9d3e72b4ebe
(cherry picked from commit a1318ae187)

neutron/agent/l3_ha_agent.py

@@ -207,13 +207,15 @@ class AgentMixin(object):
     def _add_default_gw_virtual_route(self, ri, ex_gw_port, interface_name):
         gw_ip = ex_gw_port['subnet']['gateway_ip']
         if gw_ip:
+            default_gw = ('0.0.0.0/0' if netaddr.IPAddress(gw_ip).version == 4
+                          else '::/0')
             instance = ri.keepalived_manager.config.get_instance(ri.ha_vr_id)
             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 _ha_external_gateway_added(self, ri, ex_gw_port, interface_name):
         self._add_vip(ri, ex_gw_port['ip_cidr'], interface_name)
@@ -263,8 +265,9 @@ class AgentMixin(object):
         instance = ri.keepalived_manager.config.get_instance(ri.ha_vr_id)
 
         # 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'],

neutron/tests/functional/agent/test_l3_agent.py

@@ -62,12 +62,18 @@ class L3AgentTestFramework(base.BaseOVSLinuxTestCase):
 
         mock.patch.object(self.agent, '_send_gratuitous_arp_packet').start()
 
-    def manage_router(self, enable_ha):
-        router = test_l3_agent.prepare_router_data(enable_snat=True,
-                                                   enable_floating_ip=True,
-                                                   enable_ha=enable_ha)
-        self.addCleanup(self._delete_router, router['id'])
-        ri = self._create_router(router)
+    def manage_router(self, enable_ha, ip_version=4, enable_fip=True,
+                      enable_snat=True):
+        if ip_version == 6:
+            enable_snat = False
+            enable_fip = False
+
+        r = test_l3_agent.prepare_router_data(ip_version=ip_version,
+                                              enable_snat=enable_snat,
+                                              enable_floating_ip=enable_fip,
+                                              enable_ha=enable_ha)
+        self.addCleanup(self._delete_router, r['id'])
+        ri = self._create_router(r)
         return ri
 
     def _create_router(self, router):
@@ -183,6 +189,9 @@ class L3AgentTestCase(L3AgentTestFramework):
     def test_ha_router_lifecycle(self):
         self._router_lifecycle(enable_ha=True)
 
+    def test_ipv6_ha_router_lifecycle(self):
+        self._router_lifecycle(enable_ha=True, ip_version=6)
+
     def test_keepalived_configuration(self):
         router = self.manage_router(enable_ha=True)
         expected = self.get_expected_keepalive_configuration(router)
@@ -214,8 +223,8 @@ class L3AgentTestCase(L3AgentTestFramework):
         self.assertNotIn(old_external_device_ip, new_config)
         self.assertIn(new_external_device_ip, new_config)
 
-    def _router_lifecycle(self, enable_ha):
-        router = self.manage_router(enable_ha)
+    def _router_lifecycle(self, enable_ha, ip_version=4):
+        router = self.manage_router(enable_ha, ip_version)
 
         if enable_ha:
             port = self.agent._get_ex_gw_port(router)
@@ -236,10 +245,15 @@ class L3AgentTestCase(L3AgentTestFramework):
         self.assertTrue(self._metadata_proxy_exists(router))
         self._assert_internal_devices(router)
         self._assert_external_device(router)
-        self._assert_gateway(router)
-        self._assert_floating_ips(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._assert_floating_ips(router)
+            self._assert_snat_chains(router)
+            self._assert_floating_ip_chains(router)
 
         if enable_ha:
             self._assert_ha_device(router)

neutron/tests/unit/test_l3_agent.py

@@ -213,9 +213,9 @@ 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)