Allow reading a tenant router's external IP

Adds an external IPs field to the external gateway information
for a router so the external IP address of the router can be
read by the tenant.

DocImpact

Closes-Bug: #1255142
Change-Id: If4e77c445e9b855ff77deea6c8df4a0b3cf249d4
(cherry picked from commit c7baaa068ed1d3c8b02717232edef60ba1b655f6)

6 files changed, 50 insertions, 9 deletions

diff --git a/neutron/db/l3_db.py b/neutron/db/l3_db.py
index afc01a33bb..709c99cb0d 100644
--- a/neutron/db/l3_db.py
+++ b/neutron/db/l3_db.py
@@ -101,7 +101,11 @@ class L3_NAT_dbonly_mixin(l3.RouterPluginBase):
     def _make_router_dict(self, router, fields=None, process_extensions=True):
         res = dict((key, router[key]) for key in CORE_ROUTER_ATTRS)
         if router['gw_port_id']:
-            ext_gw_info = {'network_id': router.gw_port['network_id']}
+            ext_gw_info = {
+                'network_id': router.gw_port['network_id'],
+                'external_fixed_ips': [{'subnet_id': ip["subnet_id"],
+                                        'ip_address': ip["ip_address"]}
+                                       for ip in router.gw_port['fixed_ips']]}
         else:
             ext_gw_info = None
         res.update({
diff --git a/neutron/db/l3_gwmode_db.py b/neutron/db/l3_gwmode_db.py
index dce6cafe90..e9f081f6fc 100644
--- a/neutron/db/l3_gwmode_db.py
+++ b/neutron/db/l3_gwmode_db.py
@@ -43,7 +43,13 @@ class L3_NAT_dbonly_mixin(l3_db.L3_NAT_dbonly_mixin):
             nw_id = router_db.gw_port['network_id']
             router_res[EXTERNAL_GW_INFO] = {
                 'network_id': nw_id,
-                'enable_snat': router_db.enable_snat}
+                'enable_snat': router_db.enable_snat,
+                'external_fixed_ips': [
+                    {'subnet_id': ip["subnet_id"],
+                     'ip_address': ip["ip_address"]}
+                    for ip in router_db.gw_port['fixed_ips']
+                ]
+            }
 
     def _update_router_gw_info(self, context, router_id, info, router=None):
         # Load the router only if necessary
diff --git a/neutron/extensions/l3.py b/neutron/extensions/l3.py
index b02c9337b6..1497d9fb45 100644
--- a/neutron/extensions/l3.py
+++ b/neutron/extensions/l3.py
@@ -100,7 +100,20 @@ RESOURCE_ATTRIBUTE_MAP = {
                       'is_visible': True},
         EXTERNAL_GW_INFO: {'allow_post': True, 'allow_put': True,
                            'is_visible': True, 'default': None,
-                           'enforce_policy': True}
+                           'enforce_policy': True,
+                           'validate': {
+                               'type:dict_or_nodata': {
+                                   'network_id': {'type:uuid': None,
+                                                  'required': True},
+                                   'external_fixed_ips': {
+                                       'convert_list_to':
+                                       attr.convert_kvp_list_to_dict,
+                                       'type:fixed_ips': None,
+                                       'default': None,
+                                       'required': False,
+                                   }
+                               }
+                           }}
     },
     'floatingips': {
         'id': {'allow_post': False, 'allow_put': False,
@@ -174,6 +187,7 @@ class L3(extensions.ExtensionDescriptor):
         """Returns Ext Resources."""
         plural_mappings = resource_helper.build_plural_mappings(
             {}, RESOURCE_ATTRIBUTE_MAP)
+        plural_mappings['external_fixed_ips'] = 'external_fixed_ip'
         attr.PLURALS.update(plural_mappings)
         action_map = {'router': {'add_router_interface': 'PUT',
                                  'remove_router_interface': 'PUT'}}
diff --git a/neutron/extensions/l3_ext_gw_mode.py b/neutron/extensions/l3_ext_gw_mode.py
index 31c943a9c8..ae0ab1d54b 100644
--- a/neutron/extensions/l3_ext_gw_mode.py
+++ b/neutron/extensions/l3_ext_gw_mode.py
@@ -29,7 +29,13 @@ EXTENDED_ATTRIBUTES_2_0 = {
                  {'type:dict_or_nodata':
                   {'network_id': {'type:uuid': None, 'required': True},
                    'enable_snat': {'type:boolean': None, 'required': False,
-                                   'convert_to': attrs.convert_to_boolean}}
+                                   'convert_to': attrs.convert_to_boolean},
+                   'external_fixed_ips': {
+                       'convert_list_to': attrs.convert_kvp_list_to_dict,
+                       'validate': {'type:fixed_ips': None},
+                       'default': None,
+                       'required': False}
+                   }
                   }}}}
 
 
diff --git a/neutron/tests/unit/test_extension_ext_gw_mode.py b/neutron/tests/unit/test_extension_ext_gw_mode.py
index c119470d39..502fd1c0f9 100644
--- a/neutron/tests/unit/test_extension_ext_gw_mode.py
+++ b/neutron/tests/unit/test_extension_ext_gw_mode.py
@@ -245,14 +245,16 @@ class TestL3GwModeMixin(testlib_api.SqlTestCase,
     def test_make_router_dict_with_ext_gw(self):
         router_dict = self.target_object._make_router_dict(self.router)
         self.assertEqual({'network_id': self.ext_net_id,
-                          'enable_snat': True},
+                          'enable_snat': True,
+                          'external_fixed_ips': []},
                          router_dict[l3.EXTERNAL_GW_INFO])
 
     def test_make_router_dict_with_ext_gw_snat_disabled(self):
         self.router.enable_snat = False
         router_dict = self.target_object._make_router_dict(self.router)
         self.assertEqual({'network_id': self.ext_net_id,
-                          'enable_snat': False},
+                          'enable_snat': False,
+                          'external_fixed_ips': []},
                          router_dict[l3.EXTERNAL_GW_INFO])
 
     def test_build_routers_list_no_ext_gw(self):
@@ -364,7 +366,10 @@ class ExtGwModeIntTestCase(test_db_plugin.NeutronDbPluginV2TestCase,
                               ('admin_state_up', True), ('status', 'ACTIVE'),
                               ('external_gateway_info',
                                {'network_id': ext_net_id,
-                                'enable_snat': snat_expected_value})]
+                                'enable_snat': snat_expected_value,
+                                'external_fixed_ips': [{
+                                    'ip_address': mock.ANY,
+                                    'subnet_id': s['subnet']['id']}]})]
             with self.router(
                 name=name, admin_state_up=True, tenant_id=tenant_id,
                 external_gateway_info=input_value) as router:
diff --git a/neutron/tests/unit/test_l3_plugin.py b/neutron/tests/unit/test_l3_plugin.py
index ecb1ead448..6b82d1759c 100644
--- a/neutron/tests/unit/test_l3_plugin.py
+++ b/neutron/tests/unit/test_l3_plugin.py
@@ -1102,11 +1102,17 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
                             'remove', tenant_router['router']['id'],
                             s['subnet']['id'], None, tenant_id='tenant_a')
 
-    def test_router_add_gateway_invalid_network_returns_404(self):
+    def test_router_add_gateway_invalid_network_returns_400(self):
         with self.router() as r:
             self._add_external_gateway_to_router(
                 r['router']['id'],
-                "foobar", expected_code=exc.HTTPNotFound.code)
+                "foobar", expected_code=exc.HTTPBadRequest.code)
+
+    def test_router_add_gateway_non_existent_network_returns_404(self):
+        with self.router() as r:
+            self._add_external_gateway_to_router(
+                r['router']['id'],
+                _uuid(), expected_code=exc.HTTPNotFound.code)
 
     def test_router_add_gateway_net_not_external_returns_400(self):
         with self.router() as r: