From fc225f16a12471bfde9d5d0d378e69fba201e58a Mon Sep 17 00:00:00 2001
From: Takashi NATSUME <natsume.takashi@lab.ntt.co.jp>
Date: Wed, 1 Nov 2017 14:03:12 +0900
Subject: [PATCH] [placement] Fix foreign key constraint error

When deleting a resource provider,
if there are traits on the resource provider,
a foreign key constraint error occurs.

So add deleting trait associations for the resource provider
(records in the 'resource_provider_traits' table)
when deleting the resource provider.

Conflicts:
      nova/objects/resource_provider.py

NOTE(mriedem): The conflict is due to changes introduced by
b10f11d7e8e1afb7a12a470f92c42bf3c23eca95 in Queens which
are not needed in Pike. The test also needed to change since
1df5aad91017b4a7ef51fb6efac29e671f7cc7eb is not in Pike.

Change-Id: I6874567a14beb9b029765bf49067af6de17f2bd2
Closes-Bug: #1727719
(cherry picked from commit 5de3317d68df8fdc6fdaff62baa62822c669bb93)
---
 nova/objects/resource_provider.py             |  4 +++
 .../unit/objects/test_resource_provider.py    | 29 +++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/nova/objects/resource_provider.py b/nova/objects/resource_provider.py
index 8a39d046c960..16ef01d5aa76 100644
--- a/nova/objects/resource_provider.py
+++ b/nova/objects/resource_provider.py
@@ -505,6 +505,10 @@ class ResourceProvider(base.NovaObject):
         RPA_model = models.ResourceProviderAggregate
         context.session.query(RPA_model).\
                 filter(RPA_model.resource_provider_id == _id).delete()
+        # delete any trait associations for the resource provider
+        RPT_model = models.ResourceProviderTrait
+        context.session.query(RPT_model).\
+                filter(RPT_model.resource_provider_id == _id).delete()
         # Now delete the RP records
         result = context.session.query(models.ResourceProvider).\
                  filter(models.ResourceProvider.id == _id).delete()
diff --git a/nova/tests/unit/objects/test_resource_provider.py b/nova/tests/unit/objects/test_resource_provider.py
index 746a9257bf1e..f0a43be78fba 100644
--- a/nova/tests/unit/objects/test_resource_provider.py
+++ b/nova/tests/unit/objects/test_resource_provider.py
@@ -140,6 +140,35 @@ class TestResourceProvider(test_objects._LocalTest):
                           objects.ResourceProvider.get_by_uuid,
                           self.context, uuids.missing)
 
+    def test_destroy_with_traits(self):
+        """Test deleting a resource provider that has a trait successfully.
+        """
+        rp = resource_provider.ResourceProvider(self.context,
+                                                uuid=uuids.rp,
+                                                name='fake_rp1')
+        rp.create()
+        custom_trait = resource_provider.Trait(self.context,
+                                               uuid=uuids.trait,
+                                               name='CUSTOM_TRAIT_1')
+        custom_trait.create()
+        rp.set_traits([custom_trait])
+
+        trl = rp.get_traits()
+        self.assertEqual(1, len(trl))
+
+        # Delete a resource provider that has a trait assosiation.
+        rp.destroy()
+
+        # Assert the record has been deleted
+        # in 'resource_provider_traits' table
+        # after Resource Provider object has been destroyed.
+        trl = rp.get_traits()
+        self.assertEqual(0, len(trl))
+        # Assert that NotFound exception is raised.
+        self.assertRaises(exception.NotFound,
+                          resource_provider.ResourceProvider.get_by_uuid,
+                          self.context, uuids.rp)
+
 
 class TestInventoryNoDB(test_objects._LocalTest):
     USES_DB = False