Fix for "Resize instance" button

Currently, "Resize instance" widget is not working because it relies on
legacy Nova API v2.46, obsoleted in Pike release. Proposed patch make
Horizon use current Nova API (>=2.47).

Note: It also cherry-picks a7956cd004 from the master branch
which avoids the extra call of flavor_get in resize server form.

Closes-Bug: #1940834
Co-Authored-By: Akihiro Motoki <amotoki@gmail.com>
Change-Id: Id2f38acfc27cdf93cc4341422873e512aaff716a

5 files changed, 103 insertions, 22 deletions

diff --git a/openstack_dashboard/dashboards/project/instances/tables.py b/openstack_dashboard/dashboards/project/instances/tables.py
index 674ebdca2..624a59597 100644
--- a/openstack_dashboard/dashboards/project/instances/tables.py
+++ b/openstack_dashboard/dashboards/project/instances/tables.py
@@ -39,6 +39,8 @@ from horizon.utils import filters
 from openstack_dashboard import api
 from openstack_dashboard.dashboards.project.floating_ips import workflows
 from openstack_dashboard.dashboards.project.instances import tabs
+from openstack_dashboard.dashboards.project.instances \
+    import utils as instance_utils
 from openstack_dashboard.dashboards.project.instances.workflows \
     import resize_instance
 from openstack_dashboard.dashboards.project.instances.workflows \
@@ -789,8 +791,8 @@ class UpdateRow(tables.Row):
     def get_data(self, request, instance_id):
         instance = api.nova.server_get(request, instance_id)
         try:
-            instance.full_flavor = api.nova.flavor_get(request,
-                                                       instance.flavor["id"])
+            instance.full_flavor = instance_utils.resolve_flavor(request,
+                                                                 instance)
         except Exception:
             exceptions.handle(request,
                               _('Unable to retrieve flavor information '
@@ -1041,7 +1043,7 @@ def get_flavor(instance):
             "size_disk": size_disk,
             "size_ram": size_ram,
             "vcpus": instance.full_flavor.vcpus,
-            "flavor_id": instance.full_flavor.id
+            "flavor_id": getattr(instance.full_flavor, 'id', None)
         }
         return template.loader.render_to_string(template_name, context)
     return _("Not available")
diff --git a/openstack_dashboard/dashboards/project/instances/tests.py b/openstack_dashboard/dashboards/project/instances/tests.py
index 69cf67e40..5eafb48b2 100644
--- a/openstack_dashboard/dashboards/project/instances/tests.py
+++ b/openstack_dashboard/dashboards/project/instances/tests.py
@@ -4147,13 +4147,26 @@ class InstanceTests2(InstanceTestBase, InstanceTableTestMixin):
     def test_disassociate_floating_ip_with_release(self):
         self._test_disassociate_floating_ip(is_release=True)
 
+    def _populate_server_flavor_nova_api_ge_2_47(self, server):
+        flavor_id = server.flavor['id']
+        flavor = self.flavors.get(id=flavor_id)
+        server.flavor = {
+            'original_name': flavor.name,
+            'vcpus': flavor.vcpus,
+            'ram': flavor.ram,
+            'swap': flavor.swap,
+            'disk': flavor.disk,
+            'ephemeral': flavor.ephemeral,
+            'extra_specs': flavor.extra_specs,
+        }
+        return server
+
     @helpers.create_mocks({api.nova: ('server_get',
                                       'flavor_list',
                                       'server_group_list',
                                       'tenant_absolute_limits',
                                       'is_feature_available')})
-    def test_instance_resize_get(self):
-        server = self.servers.first()
+    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_server_group_list.return_value = self.server_groups.list()
@@ -4162,14 +4175,35 @@ class InstanceTests2(InstanceTestBase, InstanceTableTestMixin):
         url = reverse('horizon:project:instances:resize', args=[server.id])
         res = self.client.get(url)
 
+        workflow = res.context['workflow']
         self.assertTemplateUsed(res, views.WorkflowView.template_name)
+        self.assertEqual(res.context['workflow'].name,
+                         workflows.ResizeInstance.name)
+        self.assertContains(res, 'Disk Partition')
 
         config_drive_field_label = 'Configuration Drive'
         self.assertNotContains(res, config_drive_field_label)
 
+        step = workflow.get_step("flavor_choice")
+        self.assertEqual(step.action.initial['old_flavor_name'],
+                         self.flavors.first().name)
+
+        step = workflow.get_step("setadvancedaction")
+        self.assertEqual(step.action.fields['disk_config'].label,
+                         'Disk Partition')
+        self.assertQuerysetEqual(workflow.steps,
+                                 ['<SetFlavorChoice: flavor_choice>',
+                                  '<SetAdvanced: setadvancedaction>'])
         option = '<option value="%s">%s</option>'
+
+        def is_original_flavor(server, flavor, nova_api_lt_2_47):
+            if nova_api_lt_2_47:
+                return flavor.id == server.flavor['id']
+            else:
+                return flavor.name == server.flavor['original_name']
+
         for flavor in self.flavors.list():
-            if flavor.id == server.flavor['id']:
+            if is_original_flavor(server, flavor, nova_api_lt_2_47):
                 self.assertNotContains(res, option % (flavor.id, flavor.name))
             else:
                 self.assertContains(res, option % (flavor.id, flavor.name))
@@ -4184,6 +4218,15 @@ class InstanceTests2(InstanceTestBase, InstanceTableTestMixin):
         self.mock_tenant_absolute_limits.assert_called_once_with(
             helpers.IsHttpRequest(), reserved=True)
 
+    def test_instance_resize_get_nova_api_lt_2_47(self):
+        server = self.servers.first()
+        self._test_instance_resize_get(server, nova_api_lt_2_47=True)
+
+    def test_instance_resize_get_nova_api_ge_2_47(self):
+        server = self.servers.first()
+        self._populate_server_flavor_nova_api_ge_2_47(server)
+        self._test_instance_resize_get(server)
+
     @helpers.create_mocks({api.nova: ('server_get',)})
     def test_instance_resize_get_server_get_exception(self):
         server = self.servers.first()
@@ -4202,7 +4245,6 @@ class InstanceTests2(InstanceTestBase, InstanceTableTestMixin):
                                       'flavor_list',)})
     def test_instance_resize_get_flavor_list_exception(self):
         server = self.servers.first()
-
         self.mock_server_get.return_value = server
         self.mock_flavor_list.side_effect = self.exceptions.nova
 
@@ -4216,6 +4258,8 @@ class InstanceTests2(InstanceTestBase, InstanceTableTestMixin):
                                                      server.id)
         self.mock_flavor_list.assert_called_once_with(helpers.IsHttpRequest())
 
+    # 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.
     @helpers.create_mocks({api.nova: ('server_get',
                                       'flavor_list',
                                       'flavor_get',
diff --git a/openstack_dashboard/dashboards/project/instances/utils.py b/openstack_dashboard/dashboards/project/instances/utils.py
index 11bd5dc68..0639690db 100644
--- a/openstack_dashboard/dashboards/project/instances/utils.py
+++ b/openstack_dashboard/dashboards/project/instances/utils.py
@@ -10,6 +10,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from collections import namedtuple
 import logging
 from operator import itemgetter
 
@@ -232,3 +233,45 @@ def server_group_field_data(request):
         return [("", _("Select Server Group")), ] + server_groups_list
 
     return [("", _("No server groups available")), ]
+
+
+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
+    """
+    def flavor_from_dict(flavor_dict):
+        """Creates flavor-like objects from dictionary
+
+        :param flavor_dict: dictionary contains vcpu, ram, name, etc. values
+        :return: novaclient.v2.flavors.Flavor like object
+        """
+        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:
+            msg = _('Unable to retrieve flavor information '
+                    'for instance "%s".') % instance.id
+            exceptions.handle(request, msg, ignore=True)
+            fallback_flavor = {
+                'vcpus': 0, 'ram': 0, 'disk': 0, 'ephemeral': 0, 'swap': 0,
+                'name': _('Not available'),
+                'original_name': _('Not available'),
+                'extra_specs': {},
+            }
+            fallback_flavor.update(kwargs)
+            return flavor_from_dict(fallback_flavor)
+    else:
+        instance.flavor['name'] = instance.flavor['original_name']
+        return flavor_from_dict(instance.flavor)
diff --git a/openstack_dashboard/dashboards/project/instances/views.py b/openstack_dashboard/dashboards/project/instances/views.py
index f767c538f..29f3a1b8d 100644
--- a/openstack_dashboard/dashboards/project/instances/views.py
+++ b/openstack_dashboard/dashboards/project/instances/views.py
@@ -51,6 +51,8 @@ from openstack_dashboard.dashboards.project.instances \
 from openstack_dashboard.dashboards.project.instances \
     import tabs as project_tabs
 from openstack_dashboard.dashboards.project.instances \
+    import utils as instance_utils
+from openstack_dashboard.dashboards.project.instances \
     import workflows as project_workflows
 from openstack_dashboard.dashboards.project.networks.ports \
     import views as port_views
@@ -607,19 +609,9 @@ class ResizeView(workflows.WorkflowView):
             redirect = reverse("horizon:project:instances:index")
             msg = _('Unable to retrieve instance details.')
             exceptions.handle(self.request, msg, redirect=redirect)
-        flavor_id = instance.flavor['id']
         flavors = self.get_flavors()
-        if flavor_id in flavors:
-            instance.flavor_name = flavors[flavor_id].name
-        else:
-            try:
-                flavor = api.nova.flavor_get(self.request, flavor_id)
-                instance.flavor_name = flavor.name
-            except Exception:
-                msg = _('Unable to retrieve flavor information for instance '
-                        '"%s".') % instance_id
-                exceptions.handle(self.request, msg, ignore=True)
-                instance.flavor_name = _("Not available")
+        flavor = instance_utils.resolve_flavor(self.request, instance, flavors)
+        instance.flavor_name = flavor.name
         return instance
 
     @memoized.memoized_method
@@ -640,7 +632,6 @@ class ResizeView(workflows.WorkflowView):
             initial.update(
                 {'instance_id': self.kwargs['instance_id'],
                  'name': getattr(_object, 'name', None),
-                 'old_flavor_id': _object.flavor['id'],
                  'old_flavor_name': getattr(_object, 'flavor_name', ''),
                  'flavors': self.get_flavors()})
         return initial
diff --git a/openstack_dashboard/dashboards/project/instances/workflows/resize_instance.py b/openstack_dashboard/dashboards/project/instances/workflows/resize_instance.py
index bbc6906c5..80b12383d 100644
--- a/openstack_dashboard/dashboards/project/instances/workflows/resize_instance.py
+++ b/openstack_dashboard/dashboards/project/instances/workflows/resize_instance.py
@@ -47,11 +47,12 @@ class SetFlavorChoiceAction(workflows.Action):
                               "_flavors_and_quotas.html")
 
     def populate_flavor_choices(self, request, context):
-        old_flavor_id = context.get('old_flavor_id')
+        old_flavor_name = context.get('old_flavor_name')
         flavors = context.get('flavors').values()
 
         # Remove current flavor from the list of flavor choices
-        flavors = [flavor for flavor in flavors if flavor.id != old_flavor_id]
+        flavors = [flavor for flavor in flavors
+                   if flavor.name != old_flavor_name]
 
         if flavors:
             if len(flavors) > 1: