DB & Object layer for node.shard

DB and object implementations for new node.shard key.

Story: 2010768
Task: 46624
Change-Id: Ia7ef3cffc321c93501b1cc5185972a4ac1dcb212

11 files changed, 132 insertions, 4 deletions

diff --git a/ironic/api/controllers/v1/node.py b/ironic/api/controllers/v1/node.py
index 312143500..4b2f61b1c 100644
--- a/ironic/api/controllers/v1/node.py
+++ b/ironic/api/controllers/v1/node.py
@@ -180,6 +180,7 @@ def node_schema():
             'retired': {'type': ['string', 'boolean', 'null']},
             'retired_reason': {'type': ['string', 'null']},
             'secure_boot': {'type': ['string', 'boolean', 'null']},
+            'shard': {'type': ['string', 'null']},
             'storage_interface': {'type': ['string', 'null']},
             'uuid': {'type': ['string', 'null']},
             'vendor_interface': {'type': ['string', 'null']},
@@ -1383,6 +1384,7 @@ def _get_fields_for_node_query(fields=None):
                     'retired',
                     'retired_reason',
                     'secure_boot',
+                    'shard',
                     'storage_interface',
                     'target_power_state',
                     'target_provision_state',
diff --git a/ironic/common/release_mappings.py b/ironic/common/release_mappings.py
index 79636e30e..6d96bf20b 100644
--- a/ironic/common/release_mappings.py
+++ b/ironic/common/release_mappings.py
@@ -516,7 +516,7 @@ RELEASE_MAPPING = {
         'objects': {
             'Allocation': ['1.1'],
             'BIOSSetting': ['1.1'],
-            'Node': ['1.36'],
+            'Node': ['1.37'],
             'NodeHistory': ['1.0'],
             'NodeInventory': ['1.0'],
             'Conductor': ['1.3'],
diff --git a/ironic/db/api.py b/ironic/db/api.py
index dc723a5fc..a9024f66b 100644
--- a/ironic/db/api.py
+++ b/ironic/db/api.py
@@ -72,6 +72,7 @@ class Connection(object, metaclass=abc.ABCMeta):
                         :reserved_by_any_of: [conductor1, conductor2]
                         :resource_class: resource class name
                         :retired: True | False
+                        :shard_in: shard (multiple possibilities)
                         :provision_state: provision state of node
                         :provision_state_in:
                             provision state of node (multiple possibilities)
@@ -106,6 +107,7 @@ class Connection(object, metaclass=abc.ABCMeta):
                         :provisioned_before:
                             nodes with provision_updated_at field before this
                             interval in seconds
+                        :shard: nodes with the given shard
         :param limit: Maximum number of nodes to return.
         :param marker: the last item of the previous page; we return the next
                        result set.
@@ -1455,3 +1457,10 @@ class Connection(object, metaclass=abc.ABCMeta):
         :param node_id: The integer node ID.
         :returns: An inventory of a node.
         """
+
+    @abc.abstractmethod
+    def get_shard_list(self):
+        """Retrieve a list of shards.
+
+        :returns: list of dicts containing shard names and count
+        """
diff --git a/ironic/db/sqlalchemy/alembic/versions/4dbec778866e_create_node_shard.py b/ironic/db/sqlalchemy/alembic/versions/4dbec778866e_create_node_shard.py
new file mode 100644
index 000000000..a446da701
--- /dev/null
+++ b/ironic/db/sqlalchemy/alembic/versions/4dbec778866e_create_node_shard.py
@@ -0,0 +1,31 @@
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+"""create node.shard
+
+Revision ID: 4dbec778866e
+Revises: 0ac0f39bc5aa
+Create Date: 2022-11-10 14:20:59.175355
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '4dbec778866e'
+down_revision = '0ac0f39bc5aa'
+
+
+def upgrade():
+    op.add_column('nodes', sa.Column('shard', sa.String(length=255),
+                                     nullable=True))
+    op.create_index('shard_idx', 'nodes', ['shard'], unique=False)
diff --git a/ironic/db/sqlalchemy/api.py b/ironic/db/sqlalchemy/api.py
index 7a6e6862e..7e9254b05 100644
--- a/ironic/db/sqlalchemy/api.py
+++ b/ironic/db/sqlalchemy/api.py
@@ -2588,3 +2588,31 @@ class Connection(api.Connection):
             return query.one()
         except NoResultFound:
             raise exception.NodeInventoryNotFound(node_id=node_id)
+
+    def get_shard_list(self):
+        """Return a list of shards.
+
+        :returns: A list of dicts containing the keys name and count.
+        """
+        # Note(JayF): This should never be a large enough list to require
+        #             pagination. Furthermore, it wouldn't really be a sensible
+        #             thing to paginate as the data it's fetching can mutate.
+        #             So we just aren't even going to try.
+        shard_list = []
+        with _session_for_read() as session:
+            res = session.execute(
+                # Note(JayF): SQLAlchemy counts are notoriously slow because
+                #             sometimes they will use a subquery. Be careful
+                #             before changing this to use any magic.
+                sa.text(
+                    "SELECT count(id), shard from nodes group by shard;"
+                )).fetchall()
+
+            if res:
+                res.sort(key=lambda x: x[0], reverse=True)
+                for shard in res:
+                    shard_list.append(
+                        {"name": str(shard[1]), "count": shard[0]}
+                    )
+
+        return shard_list
diff --git a/ironic/db/sqlalchemy/models.py b/ironic/db/sqlalchemy/models.py
index 6fc8e21ab..29863603c 100644
--- a/ironic/db/sqlalchemy/models.py
+++ b/ironic/db/sqlalchemy/models.py
@@ -134,6 +134,7 @@ class NodeBase(Base):
         Index('reservation_idx', 'reservation'),
         Index('conductor_group_idx', 'conductor_group'),
         Index('resource_class_idx', 'resource_class'),
+        Index('shard_idx', 'shard'),
         table_args())
     id = Column(Integer, primary_key=True)
     uuid = Column(String(36))
@@ -214,6 +215,8 @@ class NodeBase(Base):
     boot_mode = Column(String(16), nullable=True)
     secure_boot = Column(Boolean, nullable=True)
 
+    shard = Column(String(255), nullable=True)
+
 
 class Node(NodeBase):
     """Represents a bare metal node."""
diff --git a/ironic/objects/node.py b/ironic/objects/node.py
index 7c6c8bc1a..93df5b3c1 100644
--- a/ironic/objects/node.py
+++ b/ironic/objects/node.py
@@ -78,7 +78,8 @@ class Node(base.IronicObject, object_base.VersionedObjectDictCompat):
     # Version 1.34: Add lessee field
     # Version 1.35: Add network_data field
     # Version 1.36: Add boot_mode and secure_boot fields
-    VERSION = '1.36'
+    # Version 1.37: Add shard field
+    VERSION = '1.37'
 
     dbapi = db_api.get_instance()
 
@@ -170,6 +171,7 @@ class Node(base.IronicObject, object_base.VersionedObjectDictCompat):
         'network_data': object_fields.FlexibleDictField(nullable=True),
         'boot_mode': object_fields.StringField(nullable=True),
         'secure_boot': object_fields.BooleanField(nullable=True),
+        'shard': object_fields.StringField(nullable=True),
     }
 
     def as_dict(self, secure=False, mask_configdrive=True):
@@ -656,6 +658,8 @@ class Node(base.IronicObject, object_base.VersionedObjectDictCompat):
             should be set to empty dict (or removed).
         Version 1.36: boot_mode, secure_boot were was added. Defaults are None.
             For versions prior to this, it should be set to None or removed.
+        Version 1.37: shard was added. Default is None. For versions prior to
+            this, it should be set to None or removed.
 
         :param target_version: the desired version of the object
         :param remove_unavailable_fields: True to remove fields that are
@@ -671,7 +675,7 @@ class Node(base.IronicObject, object_base.VersionedObjectDictCompat):
                   ('automated_clean', 28), ('protected_reason', 29),
                   ('owner', 30), ('allocation_id', 31), ('description', 32),
                   ('retired_reason', 33), ('lessee', 34), ('boot_mode', 36),
-                  ('secure_boot', 36)]
+                  ('secure_boot', 36), ('shard', 37)]
 
         for name, minor in fields:
             self._adjust_field_to_version(name, None, target_version,
diff --git a/ironic/tests/unit/db/sqlalchemy/test_migrations.py b/ironic/tests/unit/db/sqlalchemy/test_migrations.py
index f9081a6df..4abd1cbc4 100644
--- a/ironic/tests/unit/db/sqlalchemy/test_migrations.py
+++ b/ironic/tests/unit/db/sqlalchemy/test_migrations.py
@@ -1257,6 +1257,10 @@ class MigrationCheckersMixin(object):
         self.assertIsInstance(node_inventory.c.node_id.type,
                               sqlalchemy.types.Integer)
 
+    def _check_4dbec778866e(self, engine, data):
+        nodes = db_utils.get_table(engine, 'nodes')
+        self.assertIsInstance(nodes.c.shard.type, sqlalchemy.types.String)
+
     def test_upgrade_and_version(self):
         with patch_with_engine(self.engine):
             self.migration_api.upgrade('head')
diff --git a/ironic/tests/unit/db/test_shard.py b/ironic/tests/unit/db/test_shard.py
new file mode 100644
index 000000000..b4b7b129f
--- /dev/null
+++ b/ironic/tests/unit/db/test_shard.py
@@ -0,0 +1,46 @@
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+"""Tests for fetching shards via the DB API"""
+import uuid
+
+from oslo_db.sqlalchemy import enginefacade
+
+from ironic.tests.unit.db import base
+from ironic.tests.unit.db import utils
+
+
+class ShardTestCase(base.DbTestCase):
+    def setUp(self):
+        super(ShardTestCase, self).setUp()
+        self.engine = enginefacade.writer.get_engine()
+
+    def test_get_shard_list(self):
+        """Validate shard list is returned, and with correct sorting."""
+        for i in range(1, 2):
+            utils.create_test_node(uuid=str(uuid.uuid4()))
+        for i in range(1, 3):
+            utils.create_test_node(uuid=str(uuid.uuid4()), shard="shard1")
+        for i in range(1, 4):
+            utils.create_test_node(uuid=str(uuid.uuid4()), shard="shard2")
+
+        res = self.dbapi.get_shard_list()
+        self.assertEqual(res, [
+            {"name": "shard2", "count": 3},
+            {"name": "shard1", "count": 2},
+            {"name": "None", "count": 1},
+        ])
+
+    def test_get_shard_empty_list(self):
+        """Validate empty list is returned if no assigned shards."""
+        res = self.dbapi.get_shard_list()
+        self.assertEqual(res, [])
diff --git a/ironic/tests/unit/db/utils.py b/ironic/tests/unit/db/utils.py
index 87ba4b514..bc2b1244e 100644
--- a/ironic/tests/unit/db/utils.py
+++ b/ironic/tests/unit/db/utils.py
@@ -237,6 +237,7 @@ def get_test_node(**kw):
         'network_data': kw.get('network_data'),
         'boot_mode': kw.get('boot_mode', None),
         'secure_boot': kw.get('secure_boot', None),
+        'shard': kw.get('shard', None)
     }
 
     for iface in drivers_base.ALL_INTERFACES:
diff --git a/ironic/tests/unit/objects/test_objects.py b/ironic/tests/unit/objects/test_objects.py
index 017a0d210..8e903eed7 100644
--- a/ironic/tests/unit/objects/test_objects.py
+++ b/ironic/tests/unit/objects/test_objects.py
@@ -676,7 +676,7 @@ class TestObject(_LocalTest, _TestObject):
 # version bump. It is an MD5 hash of the object fields and remotable methods.
 # The fingerprint values should only be changed if there is a version bump.
 expected_object_fingerprints = {
-    'Node': '1.36-8a080e31ba89ca5f09e859bd259b54dc',
+    'Node': '1.37-6b38eb91aec57532547ea8607f95675a',
     'MyObj': '1.5-9459d30d6954bffc7a9afd347a807ca6',
     'Chassis': '1.3-d656e039fd8ae9f34efc232ab3980905',
     'Port': '1.11-97bf15b61224f26c65e90f007d78bfd2',