Base DB: rehome model_base

This change 'rehomes' model_base.py from neutron.

This is not quite a verbatim copy due to the following differences:

 - The field sizes for columns are replaced with the new constants
   from neutron_lib/db/constants.py

 - The tenant_id deprecation message is adjusted slightly.

 - The StandardAttribute table is not included.

We also add some base classes and fixtures for DB unit tests.

Partially Implements: Blueprint neutron-lib

Change-Id: I2087c6f5f66154cdaa4d8fa3d86f5e493f1d24d9

neutron_lib/db/_api.py

@@ -32,6 +32,12 @@ def _create_facade_lazily():
     return _FACADE
 
 
+def get_engine():
+    """Helper method to grab engine."""
+    facade = _create_facade_lazily()
+    return facade.get_engine()
+
+
 def get_session(autocommit=True, expire_on_commit=False, use_slave=False):
     """Helper method to grab session."""
     facade = _create_facade_lazily()

neutron_lib/db/constants.py

@@ -0,0 +1,24 @@
+#    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.
+
+# Database field sizes
+NAME_FIELD_SIZE = 255
+LONG_DESCRIPTION_FIELD_SIZE = 1024
+DESCRIPTION_FIELD_SIZE = 255
+PROJECT_ID_FIELD_SIZE = 255
+DEVICE_ID_FIELD_SIZE = 255
+DEVICE_OWNER_FIELD_SIZE = 255
+UUID_FIELD_SIZE = 36
+STATUS_FIELD_SIZE = 16
+IP_ADDR_FIELD_SIZE = 64  # large enough to hold a v4 or v6 address
+MAC_ADDR_FIELD_SIZE = 32
+RESOURCE_TYPE_FIELD_SIZE = 255

neutron_lib/db/model_base.py

@@ -0,0 +1,113 @@
+#    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.
+
+from oslo_db.sqlalchemy import models
+from oslo_utils import uuidutils
+import sqlalchemy as sa
+from sqlalchemy.ext import declarative
+from sqlalchemy import orm
+
+from neutron_lib.db import constants as db_const
+
+
+class HasProject(object):
+    """Project mixin, add to subclasses that have a user."""
+
+    # NOTE: project_id is just a free form string
+    project_id = sa.Column(sa.String(db_const.PROJECT_ID_FIELD_SIZE),
+                           index=True)
+
+    def get_tenant_id(self):
+        return self.project_id
+
+    def set_tenant_id(self, value):
+        self.project_id = value
+
+    @declarative.declared_attr
+    def tenant_id(cls):
+        return orm.synonym(
+            'project_id',
+            descriptor=property(cls.get_tenant_id, cls.set_tenant_id))
+
+
+class HasProjectNoIndex(HasProject):
+    """Project mixin, add to subclasses that have a user."""
+
+    # NOTE: project_id is just a free form string
+    project_id = sa.Column(sa.String(db_const.PROJECT_ID_FIELD_SIZE))
+
+
+class HasProjectPrimaryKeyIndex(HasProject):
+    """Project mixin, add to subclasses that have a user."""
+
+    # NOTE: project_id is just a free form string
+    project_id = sa.Column(sa.String(db_const.PROJECT_ID_FIELD_SIZE),
+                           nullable=False, primary_key=True, index=True)
+
+
+class HasProjectPrimaryKey(HasProject):
+    """Project mixin, add to subclasses that have a user."""
+
+    # NOTE: project_id is just a free form string
+    project_id = sa.Column(sa.String(db_const.PROJECT_ID_FIELD_SIZE),
+                           nullable=False, primary_key=True)
+
+
+class HasId(object):
+    """id mixin, add to subclasses that have an id."""
+
+    id = sa.Column(sa.String(db_const.UUID_FIELD_SIZE),
+                   primary_key=True,
+                   default=uuidutils.generate_uuid)
+
+
+class HasStatusDescription(object):
+    """Status with description mixin."""
+
+    status = sa.Column(sa.String(db_const.STATUS_FIELD_SIZE),
+                       nullable=False)
+    status_description = sa.Column(sa.String(db_const.DESCRIPTION_FIELD_SIZE))
+
+
+class _NeutronBase(models.ModelBase):
+    """Base class for Neutron Models."""
+
+    __table_args__ = {'mysql_engine': 'InnoDB'}
+
+    def __iter__(self):
+        self._i = iter(orm.object_mapper(self).columns)
+        return self
+
+    def next(self):
+        n = next(self._i).name
+        return n, getattr(self, n)
+
+    __next__ = next
+
+    def __repr__(self):
+        """sqlalchemy based automatic __repr__ method."""
+        items = ['%s=%r' % (col.name, getattr(self, col.name))
+                 for col in self.__table__.columns]
+        return "<%s.%s[object at %x] {%s}>" % (self.__class__.__module__,
+                                               self.__class__.__name__,
+                                               id(self), ', '.join(items))
+
+
+class NeutronBaseV2(_NeutronBase):
+
+    @declarative.declared_attr
+    def __tablename__(cls):
+        # Use the pluralized name of the class as the table name.
+        return cls.__name__.lower() + 's'
+
+
+BASEV2 = declarative.declarative_base(cls=NeutronBaseV2)

neutron_lib/tests/unit/db/_base.py

@@ -0,0 +1,51 @@
+#    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.
+
+"""
+Base classes for unit tests needing DB backend.
+Only sqlite is supported in neutron-lib.
+"""
+
+import fixtures
+
+from neutron_lib.db import _api as db_api
+from neutron_lib.db import model_base
+
+from neutron_lib.tests import _base as base
+
+
+class SqlFixture(fixtures.Fixture):
+
+    # flag to indicate that the models have been loaded
+    _TABLES_ESTABLISHED = False
+
+    def _setUp(self):
+        # Register all data models
+        engine = db_api.get_engine()
+        if not SqlFixture._TABLES_ESTABLISHED:
+            model_base.BASEV2.metadata.create_all(engine)
+            SqlFixture._TABLES_ESTABLISHED = True
+
+        def clear_tables():
+            with engine.begin() as conn:
+                for table in reversed(
+                        model_base.BASEV2.metadata.sorted_tables):
+                    conn.execute(table.delete())
+
+        self.addCleanup(clear_tables)
+
+
+class SqlTestCase(base.BaseTestCase):
+
+    def setUp(self):
+        super(SqlTestCase, self).setUp()
+        self.useFixture(SqlFixture())

neutron_lib/tests/unit/db/test_model_base.py

@@ -0,0 +1,61 @@
+#    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.
+
+import sqlalchemy as sa
+
+from neutron_lib import _context as context
+from neutron_lib.db import model_base
+
+from neutron_lib.tests.unit.db import _base as db_base
+
+
+class TestTable(model_base.BASEV2, model_base.HasProject,
+                model_base.HasId, model_base.HasStatusDescription):
+
+    name = sa.Column(sa.String(8), primary_key=True)
+
+
+class TestModelBase(db_base.SqlTestCase):
+
+    def setUp(self):
+        super(TestModelBase, self).setUp()
+        self.ctx = context.Context('user', 'project')
+        self.session = self.ctx.session
+
+    def test_model_base(self):
+        foo = TestTable(name='meh')
+        self.assertEqual('meh', foo.name)
+        self.assertIn('meh', str(foo))  # test foo.__repr__
+        cols = [k for k, _v in foo]  # test foo.__iter__ and foo.next
+        self.assertIn('name', cols)
+
+    def test_get_set_tenant_id_tenant(self):
+        foo = TestTable(tenant_id='tenant')
+        self.assertEqual('tenant', foo.get_tenant_id())
+        foo.set_tenant_id('project')
+        self.assertEqual('project', foo.get_tenant_id())
+
+    def test_get_set_tenant_id_project(self):
+        foo = TestTable(project_id='project')
+        self.assertEqual('project', foo.get_tenant_id())
+        foo.set_tenant_id('tenant')
+        self.assertEqual('tenant', foo.get_tenant_id())
+
+    def test_project_id_attribute(self):
+        foo = TestTable(project_id='project')
+        self.assertEqual('project', foo.project_id)
+        self.assertEqual('project', foo.tenant_id)
+
+    def test_tenant_id_attribute(self):
+        foo = TestTable(project_id='project')
+        self.assertEqual('project', foo.project_id)
+        self.assertEqual('project', foo.tenant_id)

requirements.txt

@@ -5,6 +5,7 @@
 pbr>=1.6 # Apache-2.0
 Babel>=2.3.4 # BSD
 
+SQLAlchemy>=1.0.10,<1.1.0 # MIT
 debtcollector>=1.2.0 # Apache-2.0
 oslo.config>=3.14.0 # Apache-2.0
 oslo.context>=2.6.0 # Apache-2.0

test-requirements.txt

@@ -5,6 +5,8 @@
 hacking<0.12,>=0.11.0 # Apache-2.0
 
 coverage>=3.6 # Apache-2.0
+discover # BSD
+fixtures>=3.0.0 # Apache-2.0/BSD
 python-subunit>=0.0.18 # Apache-2.0/BSD
 sphinx!=1.3b1,<1.3,>=1.2.1 # BSD
 oslosphinx!=3.4.0,>=2.5.0 # Apache-2.0
@@ -12,6 +14,7 @@ oslotest>=1.10.0 # Apache-2.0
 os-api-ref>=0.4.0 # Apache-2.0
 os-testr>=0.7.0 # Apache-2.0
 testrepository>=0.0.18 # Apache-2.0/BSD
+testresources>=0.2.4 # Apache-2.0/BSD
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=1.4.0 # MIT
 pep8==1.5.7 # MIT