Avoid extra flavor_get in resize server form

commit d269b1640f fixes the bug on
the resize server form, but it introduced an extra flavor_get call
even when we retrieve the list of flavors. This commit recovers
the previous behavior that we first looks up the list of flavors.

Related-Bug: #1940834
Change-Id: I891aa6b8652f330326535732d0886362dfabb989

openstack_dashboard/dashboards/project/instances/tests.py

@@ -2172,13 +2172,11 @@ class InstanceTests2(InstanceTestBase, InstanceTableTestMixin):
     @helpers.create_mocks({api.nova: ('server_get',
                                       'flavor_list',
                                       'tenant_absolute_limits',
-                                      'is_feature_available',
-                                      'flavor_get')})
+                                      'is_feature_available')})
     def _test_instance_resize_get(self, server, nova_api_lt_2_47=False):
         self.mock_server_get.return_value = server
         self.mock_flavor_list.return_value = self.flavors.list()
         self.mock_tenant_absolute_limits.return_value = self.limits['absolute']
-        self.mock_flavor_get.return_value = self.flavors.first()
 
         url = reverse('horizon:project:instances:resize', args=[server.id])
         res = self.client.get(url)
@@ -2220,11 +2218,6 @@ class InstanceTests2(InstanceTestBase, InstanceTableTestMixin):
             mock.call(helpers.IsHttpRequest()))
         self.mock_tenant_absolute_limits.assert_called_once_with(
             helpers.IsHttpRequest(), reserved=True)
-        if nova_api_lt_2_47:
-            self.mock_flavor_get.assert_called_once_with(
-                helpers.IsHttpRequest(), server.flavor['id'])
-        else:
-            self.mock_flavor_get.assert_not_called()
 
     def test_instance_resize_get_nova_api_lt_2_47(self):
         server = self.servers.first()
@@ -2250,11 +2243,9 @@ class InstanceTests2(InstanceTestBase, InstanceTableTestMixin):
             helpers.IsHttpRequest(), server.id)
 
     @helpers.create_mocks({api.nova: ('server_get',
-                                      'flavor_list',
-                                      'flavor_get')})
-    def _test_instance_resize_get_flavor_list_exception(
-            self, server, nova_api_lt_2_47=False):
-        self.mock_server_get.return_value = server
+                                      'flavor_list',)})
+    def test_instance_resize_get_flavor_list_exception(self):
+        server = self.servers.first()
         self.mock_flavor_list.side_effect = self.exceptions.nova
 
         url = reverse('horizon:project:instances:resize',
@@ -2266,21 +2257,6 @@ class InstanceTests2(InstanceTestBase, InstanceTableTestMixin):
         self.mock_server_get.assert_called_once_with(helpers.IsHttpRequest(),
                                                      server.id)
         self.mock_flavor_list.assert_called_once_with(helpers.IsHttpRequest())
-        if nova_api_lt_2_47:
-            self.mock_flavor_get.assert_called_once_with(
-                helpers.IsHttpRequest(), server.flavor['id'])
-        else:
-            self.mock_flavor_get.assert_not_called()
-
-    def test_instance_resize_get_flavor_list_exception_nova_api_lt_2_47(self):
-        server = self.servers.first()
-        self._test_instance_resize_get_flavor_list_exception(
-            server, nova_api_lt_2_47=True)
-
-    def test_instance_resize_get_flavor_list_exception(self):
-        server = self.servers.first()
-        self._populate_server_flavor_nova_api_ge_2_47(server)
-        self._test_instance_resize_get_flavor_list_exception(server)
 
     # TODO(amotoki): This is requred only when nova API <=2.46 is used.
     # Once server_get() uses nova API >=2.47 only, this test can be droppped.

openstack_dashboard/dashboards/project/instances/utils.py

@@ -236,11 +236,12 @@ def server_group_field_data(request):
     return [("", _("No server groups available")), ]
 
 
-def resolve_flavor(request, instance, **kwargs):
+def resolve_flavor(request, instance, flavors=None, **kwargs):
     """Resolves name of instance flavor independent of API microversion
 
     :param request: django http request object
     :param instance: api._nova.Server instance to resolve flavor
+    :param flavors: dict of flavors already retrieved
     :param kwargs: flavor parameters to return if hit some flavor discrepancy
     :return: flavor name or default placeholder
     """
@@ -252,8 +253,12 @@ def resolve_flavor(request, instance, **kwargs):
         """
         return namedtuple('Flavor', flavor_dict.keys())(*flavor_dict.values())
 
+    if flavors is None:
+        flavors = {}
     flavor_id = instance.flavor.get('id')
     if flavor_id:  # Nova API <=2.46
+        if flavor_id in flavors:
+            return flavors[flavor_id]
         try:
             return api.nova.flavor_get(request, flavor_id)
         except Exception:

openstack_dashboard/dashboards/project/instances/views.py

@@ -588,8 +588,9 @@ class ResizeView(workflows.WorkflowView):
             redirect = reverse("horizon:project:instances:index")
             msg = _('Unable to retrieve instance details.')
             exceptions.handle(self.request, msg, redirect=redirect)
-        instance.flavor_name = instance_utils.resolve_flavor(self.request,
-                                                             instance).name
+        flavors = self.get_flavors()
+        flavor = instance_utils.resolve_flavor(self.request, instance, flavors)
+        instance.flavor_name = flavor.name
         return instance
 
     @memoized.memoized_method