From b29ccf8aa5cf2081ed46ac53741a8600ae40f071 Mon Sep 17 00:00:00 2001
From: Balazs Gibizer <balazs.gibizer@est.tech>
Date: Fri, 14 May 2021 09:49:08 +0200
Subject: [PATCH] Support same_subtree in allocation_canadidate query

Extend the allocation candidate query generation to include same_subtree
query parameters based on the RequestSpec.

The same_subtree parameter is available since placement microversion
1.36 but we already bumped our minimum placement requirement to 1.36
in a previous patch.

Change-Id: I7447bbb49fcee5197b176aa64fd5f2c930f70fc0
blueprint: qos-minimum-guaranteed-packet-rate
---
 nova/objects/request_spec.py            |  7 +++++++
 nova/scheduler/utils.py                 |  5 +++++
 nova/tests/unit/scheduler/test_utils.py | 22 ++++++++++++++++++++++
 3 files changed, 34 insertions(+)

diff --git a/nova/objects/request_spec.py b/nova/objects/request_spec.py
index a3efbd0bf51d..ce4529b2a2f2 100644
--- a/nova/objects/request_spec.py
+++ b/nova/objects/request_spec.py
@@ -200,6 +200,12 @@ class RequestSpec(base.NovaObject):
         # respective obj_load_attr methods.
         return self.request_level_params.root_forbidden
 
+    @property
+    def same_subtree(self):
+        # self.request_level_params and .same_subtree lazy-default via their
+        # respective obj_load_attr methods.
+        return self.request_level_params.same_subtree
+
     def _image_meta_from_image(self, image):
         if isinstance(image, objects.ImageMeta):
             self.image = image
@@ -533,6 +539,7 @@ class RequestSpec(base.NovaObject):
         # NOTE(efried): We don't need to handle request_level_params here yet
         #  because they're set dynamically by the scheduler. That could change
         #  in the future.
+        # TODO(gibi): handle same_subtree here coming from the neutron ports
 
         # NOTE(sbauza): Default the other fields that are not part of the
         # original contract
diff --git a/nova/scheduler/utils.py b/nova/scheduler/utils.py
index d3d13ce0e4bb..b68a165480a4 100644
--- a/nova/scheduler/utils.py
+++ b/nova/scheduler/utils.py
@@ -70,6 +70,7 @@ class ResourceRequest(object):
         self._limit = CONF.scheduler.max_placement_results
         self._root_required: ty.Set[str] = set()
         self._root_forbidden: ty.Set[str] = set()
+        self._same_subtree: ty.List[ty.List[str]] = []
         self.suffixed_groups_from_flavor = 0
         # TODO(stephenfin): Remove this parameter once we drop support for
         # 'vcpu_pin_set'
@@ -132,6 +133,7 @@ class ResourceRequest(object):
         res_req._root_required = request_spec.root_required
         # root_required+=!these
         res_req._root_forbidden = request_spec.root_forbidden
+        res_req._same_subtree = request_spec.same_subtree
 
         # TODO(efried): Handle member_of[$S], which will need to be reconciled
         # with destination.aggregates handling in resources_from_request_spec
@@ -513,6 +515,9 @@ class ResourceRequest(object):
                                                   sorted(self._root_forbidden)]
             qparams.append(('root_required', ','.join(vals)))
 
+        for group_suffixes in self._same_subtree:
+            qparams.append(('same_subtree', ','.join(sorted(group_suffixes))))
+
         for rg in self._rg_by_id.values():
             # [('resources[$S]', 'rclass:amount,rclass:amount,...'),
             #  ('required[$S]', 'trait_name,!trait_name,...'),
diff --git a/nova/tests/unit/scheduler/test_utils.py b/nova/tests/unit/scheduler/test_utils.py
index 9763dc238b8c..4790d4a18e59 100644
--- a/nova/tests/unit/scheduler/test_utils.py
+++ b/nova/tests/unit/scheduler/test_utils.py
@@ -771,6 +771,28 @@ class TestUtils(TestUtilsBase):
         )
         self.assertEqual(expected_querystring, resources.to_querystring())
 
+    def test_resources_from_request_spec_with_same_subtree(self):
+        """Tests that there same_subtree query params are added to the
+        GET /allocation_candidates query string based on the request spec
+        """
+        flavor = objects.Flavor(
+            vcpus=1, memory_mb=1024, root_gb=15, ephemeral_gb=0, swap=0)
+        req_lvl_params = objects.RequestLevelParams(
+            same_subtree=[['group1', 'group2'], ['group3', 'group4']])
+        request_spec = objects.RequestSpec(
+            flavor=flavor, request_level_params=req_lvl_params)
+
+        resources = utils.resources_from_request_spec(
+            self.context, request_spec, self.mock_host_manager)
+
+        self.assertEqual(
+            'limit=1000&'
+            'resources=DISK_GB%3A15%2CMEMORY_MB%3A1024%2CVCPU%3A1&'
+            'same_subtree=group1%2Cgroup2&'
+            'same_subtree=group3%2Cgroup4',
+            resources.to_querystring()
+        )
+
     @mock.patch('nova.compute.utils.is_volume_backed_instance',
                 return_value=False)
     def test_resources_from_flavor_no_bfv(self, mock_is_bfv):