Create a table to track loaded interfaces

A helper table conductor_hardware_interfaces was created to track which
hardware types have which interfaces loaded on which conductors.

Partial-Bug: #1524745
Change-Id: Iae2f3fddb2441b6069c011cf8bf646943d34d0a4

ironic/db/sqlalchemy/alembic/versions/2353895ecfae_add_conductor_hardware_interfaces_table.py

@@ -0,0 +1,47 @@
+#    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.
+
+"""Add conductor_hardware_interfaces table
+
+Revision ID: 2353895ecfae
+Revises: 1a59178ebdf6
+Create Date: 2016-12-12 15:17:22.065056
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '2353895ecfae'
+down_revision = '1d6951876d68'
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    op.create_table('conductor_hardware_interfaces',
+                    sa.Column('id', sa.Integer(), nullable=False),
+                    sa.Column('created_at', sa.DateTime(), nullable=True),
+                    sa.Column('updated_at', sa.DateTime(), nullable=True),
+                    sa.Column('conductor_id', sa.Integer(), nullable=False),
+                    sa.Column('hardware_type', sa.String(length=255),
+                              nullable=False),
+                    sa.Column('interface_type', sa.String(length=16),
+                              nullable=False),
+                    sa.Column('interface_name', sa.String(length=255),
+                              nullable=False),
+                    sa.ForeignKeyConstraint(['conductor_id'],
+                                            ['conductors.id']),
+                    sa.PrimaryKeyConstraint('id'),
+                    sa.UniqueConstraint(
+                        'conductor_id', 'hardware_type',
+                        'interface_type', 'interface_name',
+                        name='uniq_conductorhardwareinterfaces0'))

ironic/db/sqlalchemy/models.py

@@ -88,6 +88,25 @@ class Conductor(Base):
     online = Column(Boolean, default=True)
 
 
+class ConductorHardwareInterfaces(Base):
+    """Internal table used to track what is loaded on each conductor."""
+
+    __tablename__ = 'conductor_hardware_interfaces'
+    __table_args__ = (
+        schema.UniqueConstraint(
+            'conductor_id',
+            'hardware_type',
+            'interface_type',
+            'interface_name',
+            name='uniq_conductorhardwareinterfaces0'),
+        table_args())
+    id = Column(Integer, primary_key=True)
+    conductor_id = Column(Integer, ForeignKey('conductors.id'), nullable=False)
+    hardware_type = Column(String(255), nullable=False)
+    interface_type = Column(String(16), nullable=False)
+    interface_name = Column(String(255), nullable=False)
+
+
 class Node(Base):
     """Represents a bare metal node."""
 

ironic/tests/unit/db/sqlalchemy/test_migrations.py

@@ -630,6 +630,28 @@ class MigrationCheckersMixin(object):
         self.assertIsInstance(nodes.c.storage_interface.type,
                               sqlalchemy.types.String)
 
+    def _check_2353895ecfae(self, engine, data):
+        ifaces = db_utils.get_table(engine, 'conductor_hardware_interfaces')
+        col_names = [column.name for column in ifaces.c]
+        expected_names = ['created_at', 'updated_at', 'id', 'conductor_id',
+                          'hardware_type', 'interface_type', 'interface_name']
+        self.assertEqual(sorted(expected_names), sorted(col_names))
+
+        self.assertIsInstance(ifaces.c.created_at.type,
+                              sqlalchemy.types.DateTime)
+        self.assertIsInstance(ifaces.c.updated_at.type,
+                              sqlalchemy.types.DateTime)
+        self.assertIsInstance(ifaces.c.id.type,
+                              sqlalchemy.types.Integer)
+        self.assertIsInstance(ifaces.c.conductor_id.type,
+                              sqlalchemy.types.Integer)
+        self.assertIsInstance(ifaces.c.hardware_type.type,
+                              sqlalchemy.types.String)
+        self.assertIsInstance(ifaces.c.interface_type.type,
+                              sqlalchemy.types.String)
+        self.assertIsInstance(ifaces.c.interface_name.type,
+                              sqlalchemy.types.String)
+
     def test_upgrade_and_version(self):
         with patch_with_engine(self.engine):
             self.migration_api.upgrade('head')