Add database migration for project tags

This change adds the SQL database migration for adding a new
project_tag table that consists of an project_id and name. The
project_id is the id of a project that the tag is mapped to and
the name is the string value of the tag.

Partially-Implements: bp project-tags
Co-Authored-By: Pilla, Samuel (sp516w) <sp516w@att.com>
Co-Authored-By: Tin Lam <tin@irrational.io>

Change-Id: Ib3db74cb08e7fdec01d55d8988e0906948d80a32

keystone/common/sql/contract_repo/versions/030_contract_add_project_tags_table.py

@@ -0,0 +1,15 @@
+#    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.
+
+
+def upgrade(migrate_engine):
+    pass

keystone/common/sql/core.py

@@ -71,6 +71,7 @@ PrimaryKeyConstraint = sql.PrimaryKeyConstraint
 joinedload = sql.orm.joinedload
 # Suppress flake8's unused import warning for flag_modified:
 flag_modified = flag_modified
+Unicode = sql.Unicode
 
 
 def initialize():

keystone/common/sql/data_migration_repo/versions/030_migrate_add_project_tags_table.py

@@ -0,0 +1,15 @@
+#    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.
+
+
+def upgrade(migrate_engine):
+    pass

keystone/common/sql/expand_repo/versions/030_expand_add_project_tags_table.py

@@ -0,0 +1,44 @@
+# 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 sql
+
+
+def upgrade(migrate_engine):
+
+    meta = sql.MetaData()
+    meta.bind = migrate_engine
+
+    project_table = sql.Table('project', meta, autoload=True)
+
+    # NOTE(lamt) To allow tag name to be case sensitive for MySQL, the 'name'
+    # column needs to use collation, which is incompatible with Postgresql.
+    # Using unicode to mirror nova's server tag:
+    # https://github.com/openstack/nova/blob/master/nova/db/sqlalchemy/models.py
+    project_tags_table = sql.Table(
+        'project_tag',
+        meta,
+        sql.Column('project_id',
+                   sql.String(64),
+                   sql.ForeignKey(project_table.c.id, ondelete='CASCADE'),
+                   nullable=False,
+                   primary_key=True),
+        sql.Column('name',
+                   sql.Unicode(255),
+                   nullable=False,
+                   primary_key=True),
+        sql.UniqueConstraint('project_id', 'name'),
+        mysql_engine='InnoDB',
+        mysql_charset='utf8'
+    )
+
+    project_tags_table.create(migrate_engine, checkfirst=True)

keystone/tests/unit/test_sql_upgrade.py

@@ -2421,6 +2421,74 @@ class FullMigration(SqlMigrateBase, unit.TestCase):
         pw_table = sqlalchemy.Table('password', meta, autoload=True)
         self.assertFalse(pw_table.c.created_at_int.nullable)
 
+    def test_migration_30_expand_add_project_tags_table(self):
+        self.expand(29)
+        self.migrate(29)
+        self.contract(29)
+
+        table_name = 'project_tag'
+        self.assertTableDoesNotExist(table_name)
+
+        self.expand(30)
+        self.migrate(30)
+        self.contract(30)
+
+        self.assertTableExists(table_name)
+        self.assertTableColumns(
+            table_name,
+            ['project_id', 'name'])
+
+    def test_migration_030_project_tags_works_correctly_after_migration(self):
+        if self.engine.name == 'sqlite':
+            self.skipTest('sqlite backend does not support foreign keys')
+
+        self.expand(30)
+        self.migrate(30)
+        self.contract(30)
+
+        project_table = sqlalchemy.Table(
+            'project', self.metadata, autoload=True)
+        tag_table = sqlalchemy.Table(
+            'project_tag', self.metadata, autoload=True)
+
+        session = self.sessionmaker()
+        project_id = uuid.uuid4().hex
+
+        project = {
+            'id': project_id,
+            'name': uuid.uuid4().hex,
+            'enabled': True,
+            'domain_id': resource_base.NULL_DOMAIN_ID,
+            'is_domain': False
+        }
+
+        tag = {
+            'project_id': project_id,
+            'name': uuid.uuid4().hex
+        }
+
+        self.insert_dict(session, 'project', project)
+        self.insert_dict(session, 'project_tag', tag)
+
+        tags_query = session.query(tag_table).filter_by(
+            project_id=project_id).all()
+        self.assertThat(tags_query, matchers.HasLength(1))
+
+        # Adding duplicate tags should cause error.
+        self.assertRaises(db_exception.DBDuplicateEntry,
+                          self.insert_dict,
+                          session, 'project_tag', tag)
+
+        session.execute(
+            project_table.delete().where(project_table.c.id == project_id)
+        )
+
+        tags_query = session.query(tag_table).filter_by(
+            project_id=project_id).all()
+        self.assertThat(tags_query, matchers.HasLength(0))
+
+        session.close()
+
 
 class MySQLOpportunisticFullMigration(FullMigration):
     FIXTURE = test_base.MySQLOpportunisticFixture