Set root_provider_id in the database

When nested resource provider feature was added in Rocky,
root_provider_id column, which should be non-None value, is created in
the resource provider DB.

However, online data migration is only done implicitly via listing or
showing resource providers. With this patch, executing the cli command

    `placement-manage db online_data_migrations`

makes sure all the resource providers are ready for nested provider
feature, that is, all the root_provider_ids in the DB have non-None
value.

Change-Id: I42a1afa69f379b095417f5eb106fe52ebff15017
Related-Bug:#1803925

doc/source/cli/placement-manage.rst

@@ -100,6 +100,7 @@ Placement Database
      +---------------------------------------------+-------------+-----------+
      |                  Migration                  | Total Found | Completed |
      +---------------------------------------------+-------------+-----------+
+     |            set_root_provider_ids            |      0      |     0     |
      |         create_incomplete_consumers         |      2      |     2     |
      +---------------------------------------------+-------------+-----------+
 

placement/cmd/manage.py

@@ -25,6 +25,7 @@ from placement import context
 from placement.db.sqlalchemy import migration
 from placement import db_api
 from placement.i18n import _
+from placement.objects import resource_provider as rp_obj
 
 version_info = pbr.version.VersionInfo('openstack-placement')
 LOG = logging.getLogger(__name__)
@@ -44,6 +45,7 @@ online_migrations = (
     # have finished.
 
     # Added in Stein
+    rp_obj.set_root_provider_ids,
 )
 
 

placement/objects/resource_provider.py

@@ -744,7 +744,8 @@ def _has_child_providers(context, rp_id):
 @db_api.placement_context_manager.writer
 def _set_root_provider_id(context, rp_id, root_id):
     """Simply sets the root_provider_id value for a provider identified by
-    rp_id. Used in online data migration.
+    rp_id. Used in implicit online data migration via REST API getting
+    resource providers.
 
     :param rp_id: Internal ID of the provider to update
     :param root_id: Value to set root provider to
@@ -754,6 +755,38 @@ def _set_root_provider_id(context, rp_id, root_id):
     context.session.execute(upd)
 
 
+@db_api.placement_context_manager.writer
+def set_root_provider_ids(context, batch_size):
+    """Simply sets the root_provider_id value for a provider identified by
+    rp_id. Used in explicit online data migration via CLI.
+
+    :param rp_id: Internal ID of the provider to update
+    :param root_id: Value to set root provider to
+    """
+    # UPDATE resource_providers
+    # SET root_provider_id=resource_providers.id
+    # WHERE resource_providers.id
+    # IN (SELECT subq_1.id
+    #     FROM (SELECT resource_providers.id AS id
+    #           FROM resource_providers
+    #           WHERE resource_providers.root_provider_id IS NULL
+    #           LIMIT :param_1)
+    #     AS subq_1)
+
+    subq_1 = context.session.query(_RP_TBL.c.id)
+    subq_1 = subq_1.filter(_RP_TBL.c.root_provider_id.is_(None))
+    subq_1 = subq_1.limit(batch_size)
+    subq_1 = sa.alias(subq_1.as_scalar(), name="subq_1")
+
+    subq_2 = sa.select([subq_1.c.id]).select_from(subq_1)
+
+    upd = _RP_TBL.update().where(_RP_TBL.c.id.in_(subq_2.as_scalar()))
+    upd = upd.values(root_provider_id=_RP_TBL.c.id)
+    res = context.session.execute(upd)
+
+    return res.rowcount, res.rowcount
+
+
 ProviderIds = collections.namedtuple(
     'ProviderIds', 'id uuid parent_id parent_uuid root_id root_uuid')
 

placement/tests/functional/db/test_resource_provider.py

@@ -147,6 +147,78 @@ class ResourceProviderTestCase(tb.PlacementDbBaseTestCase):
         # Make sure the object root_provider_uuid is set on load
         self.assertEqual(rp.root_provider_uuid, uuidsentinel.rp1)
 
+    def test_set_root_provider(self):
+        """Simulate old resource provider records in the database that has no
+        root_provider_uuid set and ensure the root_provider_uuid field in the
+        table is set to the provider's ID via set_root_provider_ids().
+        """
+        # First, set up records for "old-style" resource providers with
+        # no root provider UUID.
+        rp_tbl = rp_obj._RP_TBL
+        conn = self.placement_db.get_engine().connect()
+
+        ins_stmt1 = rp_tbl.insert().values(
+            id=1,
+            uuid=uuidsentinel.rp1,
+            name='rp-1',
+            root_provider_id=None,
+            parent_provider_id=None,
+            generation=42,
+        )
+        ins_stmt2 = rp_tbl.insert().values(
+            id=2,
+            uuid=uuidsentinel.rp2,
+            name='rp-2',
+            root_provider_id=None,
+            parent_provider_id=None,
+            generation=42,
+        )
+        conn.execute(ins_stmt1)
+        conn.execute(ins_stmt2)
+
+        # Second, set up records for "new-style" resource providers
+        # in a tree
+        self._create_provider('root_rp')
+        self._create_provider('child_rp', parent=uuidsentinel.root_rp)
+        self._create_provider('grandchild_rp', parent=uuidsentinel.child_rp)
+
+        # Check rp_1 that it has no root provider id
+        sel_stmt = sa.select([rp_tbl.c.root_provider_id]).where(
+            rp_tbl.c.id == 1)
+        res = conn.execute(sel_stmt).fetchall()
+        self.assertIsNone(res[0][0])
+        # Check rp_2 that it has no root provider id
+        sel_stmt = sa.select([rp_tbl.c.root_provider_id]).where(
+            rp_tbl.c.id == 2)
+        res = conn.execute(sel_stmt).fetchall()
+        self.assertIsNone(res[0][0])
+
+        # Run set_root_provider_ids()
+        found, migrated = rp_obj.set_root_provider_ids(self.ctx, batch_size=10)
+        self.assertEqual(2, found)
+        self.assertEqual(2, migrated)
+
+        # Check rp_1 that it has got the root provider id
+        sel_stmt = sa.select([rp_tbl.c.root_provider_id]).where(
+            rp_tbl.c.id == 1)
+        res = conn.execute(sel_stmt).fetchall()
+        self.assertEqual(1, res[0][0])
+        # Check rp_2 that it has got the root provider id
+        sel_stmt = sa.select([rp_tbl.c.root_provider_id]).where(
+            rp_tbl.c.id == 2)
+        res = conn.execute(sel_stmt).fetchall()
+        self.assertEqual(2, res[0][0])
+
+        # Check the new-style providers remains in a tree,
+        # which means the root provider ids are not changed
+        rps = rp_obj.ResourceProviderList.get_all_by_filters(
+            self.ctx,
+            filters={
+                'in_tree': uuidsentinel.root_rp,
+            }
+        )
+        self.assertEqual(3, len(rps))
+
     def test_inherit_root_from_parent(self):
         """Tests that if we update an existing provider's parent provider UUID,
         that the root provider UUID of the updated provider is automatically

releasenotes/notes/set_root_provider_id-53930a5d1dbd374f.yaml

@@ -0,0 +1,10 @@
+---
+features:
+  - |
+    A new online data migration has been added to populate missing
+    ``root_provider_id`` in the resource_providers table. This can
+    be run during the normal placement-manage db online_data_migrations
+    routine. See the `Bug#1803925`_ for more details.
+
+    .. _Bug#1803925: https://bugs.launchpad.net/nova/+bug/1803925
+