Integrate Rally & Alembic

Alembic allows us to change in future DB schema,
which we are going to do soon.

This patch adds under rally/common/db/sqlalchemy/migrations
required files for alembic as well as a first init migrations
that was autogenerated from models that we have.

As well this patch adds CLI commands for DB management

Change-Id: I7caa090aa5c4c6563b7e34d0d09baa039a3aa718
Co-Authored-By: Illia Khudoshyn <ikhudoshyn@mirantis.com>

.coveragerc

@@ -5,3 +5,4 @@ source = rally
 [report]
 ignore_errors = True
 precision = 3
+omit = */migrations/versions/ca3626f62937_init_migration.py

doc/source/db_migrations.rst

@@ -0,0 +1 @@
+../../rally/common/db/sqlalchemy/migrations/README.rst

doc/source/index.rst

@@ -33,6 +33,7 @@ Contents
    user_stories
    plugins
    plugin/plugin_reference
+   db_migrations
    contribute
    gates
    feature_requests

rally/cli/manage.py

@@ -28,11 +28,34 @@ class DBCommands(object):
     """Commands for DB management."""
 
     def recreate(self):
-        """Drop and create Rally database."""
-        db.db_drop()
-        db.db_create()
+        """Drop and create Rally database.
+
+        This will delete all existing data.
+        """
+        db.schema_cleanup()
+        db.schema_create()
         envutils.clear_env()
 
+    def create(self):
+        """Create Rally database."""
+        db.schema_create()
+
+    def upgrade(self):
+        """Upgrade Rally database to the latest state."""
+        db.schema_upgrade()
+
+    @cliutils.args("--revision",
+                   help=("Downgrade to specified revision UUID. "
+                         "Current revision of DB could be found by calling "
+                         "'rally-manage db revision'"))
+    def downgrade(self, revision):
+        """Downgrade Rally database."""
+        db.schema_downgrade(revision)
+
+    def revision(self):
+        """Print current Rally database revision UUID."""
+        print(db.schema_revision())
+
 
 def main():
     categories = {"db": DBCommands}

rally/common/db/api.py

@@ -65,19 +65,39 @@ def get_impl():
     return IMPL
 
 
-def db_cleanup():
-    """Recreate engine."""
-    get_impl().db_cleanup()
+def engine_reset():
+    """Reset DB engine."""
+    get_impl().engine_reset()
 
 
-def db_create():
-    """Initialize DB. This method will drop existing database."""
-    get_impl().db_create()
+def schema_cleanup():
+    """Drop DB schema. This method drops existing database."""
+    get_impl().schema_cleanup()
 
 
-def db_drop():
-    """Drop DB. This method drop existing database."""
-    get_impl().db_drop()
+def schema_upgrade(revision=None):
+    """Migrate the database to `revision` or the most recent revision."""
+    return get_impl().schema_upgrade(revision)
+
+
+def schema_create():
+    """Create database schema from models description."""
+    return get_impl().schema_create()
+
+
+def schema_downgrade(revision):
+    """Downgrade DB schema to specified revision."""
+    return get_impl().schema_downgrade(revision)
+
+
+def schema_revision():
+    """Return the schema revision."""
+    return get_impl().schema_revision()
+
+
+def schema_stamp(revision):
+    """Stamps database with provided revision."""
+    return get_impl().schema_stamp(revision)
 
 
 def task_get(uuid):

rally/common/db/sqlalchemy/alembic.ini

@@ -0,0 +1,68 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = rally.common.db.sqlalchemy:migrations
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# max length of characters to apply to the
+# "slug" field
+#truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; this defaults
+# to alembic/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path
+# version_locations = %(here)s/bar %(here)s/bat alembic/versions
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+sqlalchemy.url = driver://user:pass@localhost/dbname
+
+
+# Logging configuration
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

rally/common/db/sqlalchemy/api.py

@@ -16,6 +16,11 @@
 SQLAlchemy implementation for DB.API
 """
 
+import os
+
+import alembic
+from alembic import config as alembic_config
+import alembic.migration as alembic_migration
 from oslo_config import cfg
 from oslo_db import exception as db_exc
 from oslo_db.sqlalchemy import session as db_session
@@ -33,6 +38,8 @@ CONF = cfg.CONF
 
 _FACADE = None
 
+INITIAL_REVISION_UUID = "ca3626f62937"
+
 
 def _create_facade_lazily():
     global _FACADE
@@ -58,19 +65,93 @@ def get_backend():
     return Connection()
 
 
+def _alembic_config():
+    path = os.path.join(os.path.dirname(__file__), "alembic.ini")
+    config = alembic_config.Config(path)
+    return config
+
+
 class Connection(object):
 
-    def db_cleanup(self):
+    def engine_reset(self):
         global _FACADE
 
         _FACADE = None
 
-    def db_create(self):
-        models.create_db()
-
-    def db_drop(self):
+    def schema_cleanup(self):
         models.drop_db()
 
+    def schema_revision(self, config=None, engine=None):
+        """Current database revision.
+
+        :param config: Instance of alembic config
+        :param engine: Instance of DB engine
+        :returns: Database revision
+        :rtype: string
+        """
+        engine = engine or get_engine()
+        with engine.connect() as conn:
+            context = alembic_migration.MigrationContext.configure(conn)
+            return context.get_current_revision()
+
+    def schema_upgrade(self, revision=None, config=None, engine=None):
+        """Used for upgrading database.
+
+        :param revision: Desired database version
+        :type revision: string
+        :param config: Instance of alembic config
+        :param engine: Instance of DB engine
+        """
+        revision = revision or "head"
+        config = config or _alembic_config()
+        engine = engine or get_engine()
+
+        if self.schema_revision() is None:
+            self.schema_stamp(INITIAL_REVISION_UUID, config=config)
+
+        alembic.command.upgrade(config, revision or "head")
+
+    def schema_create(self, config=None, engine=None):
+        """Create database schema from models description.
+
+        Can be used for initial installation instead of upgrade('head').
+        :param config: Instance of alembic config
+        :param engine: Instance of DB engine
+        """
+        engine = engine or get_engine()
+
+        # NOTE(viktors): If we will use metadata.create_all() for non empty db
+        #                schema, it will only add the new tables, but leave
+        #                existing as is. So we should avoid of this situation.
+        if self.schema_revision(engine=engine) is not None:
+            raise db_exc.DbMigrationError("DB schema is already under version"
+                                          " control. Use upgrade() instead")
+
+        models.BASE.metadata.create_all(engine)
+        self.schema_stamp("head", config=config)
+
+    def schema_downgrade(self, revision, config=None):
+        """Used for downgrading database.
+
+        :param revision: Desired database revision
+        :type revision: string
+        :param config: Instance of alembic config
+        """
+        config = config or _alembic_config()
+        return alembic.command.downgrade(config, revision)
+
+    def schema_stamp(self, revision, config=None):
+        """Stamps database with provided revision.
+
+        Don't run any migrations.
+        :param revision: Should match one from repository or head - to stamp
+                         database with most recent revision
+        :type revision: string
+        :param config: Instance of alembic config
+        """
+        config = config or _alembic_config()
+        return alembic.command.stamp(config, revision=revision)
+
     def model_query(self, model, session=None):
         """The helper method to create query.
 

rally/common/db/sqlalchemy/migrations/README.rst

@@ -0,0 +1,79 @@
+..
+      Copyright 2016 Mirantis Inc. All Rights Reserved.
+
+      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.
+
+.. _db_migrations:
+
+Database upgrade/downgrade in Rally
+===================================
+
+Information for users
+---------------------
+
+Rally supports DB schema versioning (schema versions are called *revisions*)
+and migration (upgrade to later and downgrade to earlier revisions).
+
+End user is provided with the following possibilities:
+
+- Print current revision of DB.
+
+  .. code-block:: shell
+
+    rally-manage db revision
+
+- Upgrade existing DB to the latest state.
+
+  This is needed when previously existing Rally installation is being
+  upgraded to a newer version. In this case user should issue command
+
+  .. code-block:: shell
+
+    rally-manage db upgrade
+
+  **AFTER** upgrading Rally package. DB schema
+  will get upgraded to the latest state and all existing data will be kept.
+
+- Downgrade existing DB to a previous revision.
+
+  This command could be useful if user wants to return to an earlier version
+  of Rally. This could be done by issuing command
+
+  .. code-block:: shell
+
+    rally-manage db downgrade --revision <UUID>
+
+  Database schema downgrade **MUST** be done **BEFORE** Rally package is downgraded.
+  User must  provide revision UUID to which the schema must be downgraded.
+
+Information for developers
+--------------------------
+
+DB migration in Rally is implemented via package *alembic*.
+
+It is highly recommended to get familiar with it's documnetation
+available by the link_ before proceeding.
+
+.. _link: https://alembic.readthedocs.org
+
+If developer is about to change existing DB schema they should
+create new DB revision and migration script with the following command
+
+.. code-block:: shell
+
+  alembic --config rally/common/db/sqlalchemy/alembic.ini revision -m <Message>
+
+It will generate migration script -- a file named `<UUID>_<Message>.py`
+located in `rally/common/db/sqlalchemy/migrations/versions`.
+Generated script should then be checked, edited if it is needed to be
+and added to Rally source tree.

rally/common/db/sqlalchemy/migrations/env.py

@@ -0,0 +1,46 @@
+# Copyright (c) 2016 Mirantis Inc.
+# All Rights Reserved.
+#
+#    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 alembic import context
+
+from rally.common.db.sqlalchemy import api
+from rally.common.db.sqlalchemy import models
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+# from myapp import mymodel
+target_metadata = models.BASE.metadata
+
+# other values from the config, defined by the needs of env.py,
+# can be acquired:
+# my_important_option = config.get_main_option("my_important_option")
+# ... etc.
+
+
+def run_migrations_online():
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+    """
+    engine = api.get_engine()
+    with engine.connect() as connection:
+        context.configure(connection=connection,
+                          target_metadata=target_metadata)
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+run_migrations_online()

rally/common/db/sqlalchemy/migrations/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+def upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

rally/common/db/sqlalchemy/migrations/versions/ca3626f62937_init_migration.py

@@ -0,0 +1,223 @@
+# Copyright (c) 2016 Mirantis Inc.
+# All Rights Reserved.
+#
+#    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.
+
+
+"""Init migration
+
+Revision ID: ca3626f62937
+Revises:
+Create Date: 2016-01-07 00:27:39.687814
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = "ca3626f62937"
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+from alembic import op
+import sqlalchemy as sa
+
+import rally
+from rally.common.db.sqlalchemy import api
+
+
+def upgrade():
+    dialect = api.get_engine().dialect
+
+    deployments_columns = [
+        sa.Column("created_at", sa.DateTime(), nullable=True),
+        sa.Column("updated_at", sa.DateTime(), nullable=True),
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("uuid", sa.String(length=36), nullable=False),
+        sa.Column("parent_uuid", sa.String(length=36), nullable=True),
+        sa.Column("name", sa.String(length=255), nullable=True),
+        sa.Column("started_at", sa.DateTime(), nullable=True),
+        sa.Column("completed_at", sa.DateTime(), nullable=True),
+        sa.Column(
+            "config",
+            rally.common.db.sqlalchemy.types.MutableJSONEncodedDict(),
+            nullable=False),
+        sa.Column("admin", sa.PickleType(), nullable=True),
+        sa.Column("users", sa.PickleType(), nullable=False),
+        sa.Column("enum_deployments_status", sa.Enum(
+            "cleanup->failed", "cleanup->finished", "cleanup->started",
+            "deploy->failed", "deploy->finished", "deploy->inconsistent",
+            "deploy->init", "deploy->started", "deploy->subdeploy",
+            name="enum_deploy_status"), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("name")
+    ]
+
+    if dialect.name.startswith("sqlite"):
+        deployments_columns.append(
+            sa.ForeignKeyConstraint(
+                ["parent_uuid"], [u"deployments.uuid"],
+                name="fk_parent_uuid", use_alter=True)
+        )
+
+    # commands auto generated by Alembic - please adjust!
+    op.create_table("deployments", *deployments_columns)
+
+    op.create_index("deployment_parent_uuid", "deployments",
+                    ["parent_uuid"], unique=False)
+
+    op.create_index("deployment_uuid", "deployments", ["uuid"], unique=True)
+
+    if not dialect.name.startswith("sqlite"):
+        op.create_foreign_key("fk_parent_uuid", "deployments", "deployments",
+                              ["parent_uuid"], ["uuid"])
+
+    op.create_table(
+        "workers",
+        sa.Column("created_at", sa.DateTime(), nullable=True),
+        sa.Column("updated_at", sa.DateTime(), nullable=True),
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("hostname", sa.String(length=255), nullable=True),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("hostname", name="uniq_worker@hostname")
+    )
+
+    op.create_table(
+        "resources",
+        sa.Column("created_at", sa.DateTime(), nullable=True),
+        sa.Column("updated_at", sa.DateTime(), nullable=True),
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("provider_name", sa.String(length=255), nullable=True),
+        sa.Column("type", sa.String(length=255), nullable=True),
+        sa.Column(
+            "info",
+            rally.common.db.sqlalchemy.types.MutableJSONEncodedDict(),
+            nullable=False),
+        sa.Column("deployment_uuid", sa.String(length=36), nullable=False),
+        sa.ForeignKeyConstraint(["deployment_uuid"], [u"deployments.uuid"]),
+        sa.PrimaryKeyConstraint("id")
+    )
+    op.create_index("resource_deployment_uuid", "resources",
+                    ["deployment_uuid"], unique=False)
+
+    op.create_index("resource_provider_name", "resources",
+                    ["deployment_uuid", "provider_name"], unique=False)
+
+    op.create_index("resource_provider_name_and_type", "resources",
+                    ["deployment_uuid", "provider_name", "type"],
+                    unique=False)
+
+    op.create_index("resource_type", "resources",
+                    ["deployment_uuid", "type"], unique=False)
+
+    op.create_table(
+        "tasks",
+        sa.Column("created_at", sa.DateTime(), nullable=True),
+        sa.Column("updated_at", sa.DateTime(), nullable=True),
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("uuid", sa.String(length=36), nullable=False),
+        sa.Column("status", sa.Enum(
+            "aborted", "aborting", "cleaning up", "failed", "finished",
+            "init", "paused", "running", "setting up", "soft_aborting",
+            "verifying", name="enum_tasks_status"), nullable=False),
+        sa.Column("verification_log", sa.Text(), nullable=True),
+        sa.Column("tag", sa.String(length=64), nullable=True),
+        sa.Column("deployment_uuid", sa.String(length=36), nullable=False),
+        sa.ForeignKeyConstraint(["deployment_uuid"], [u"deployments.uuid"], ),
+        sa.PrimaryKeyConstraint("id")
+    )
+
+    op.create_index("task_deployment", "tasks", ["deployment_uuid"],
+                    unique=False)
+
+    op.create_index("task_status", "tasks", ["status"], unique=False)
+
+    op.create_index("task_uuid", "tasks", ["uuid"], unique=True)
+
+    op.create_table(
+        "verifications",
+        sa.Column("created_at", sa.DateTime(), nullable=True),
+        sa.Column("updated_at", sa.DateTime(), nullable=True),
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("uuid", sa.String(length=36), nullable=False),
+        sa.Column("deployment_uuid", sa.String(length=36), nullable=False),
+        sa.Column("status", sa.Enum(
+            "aborted", "aborting", "cleaning up", "failed", "finished",
+            "init", "paused", "running", "setting up", "soft_aborting",
+            "verifying", name="enum_tasks_status"), nullable=False),
+        sa.Column("set_name", sa.String(length=20), nullable=True),
+        sa.Column("tests", sa.Integer(), nullable=True),
+        sa.Column("errors", sa.Integer(), nullable=True),
+        sa.Column("failures", sa.Integer(), nullable=True),
+        sa.Column("time", sa.Float(), nullable=True),
+        sa.ForeignKeyConstraint(["deployment_uuid"], [u"deployments.uuid"], ),
+        sa.PrimaryKeyConstraint("id")
+    )
+
+    op.create_index("verification_uuid", "verifications", ["uuid"],
+                    unique=True)
+
+    op.create_table(
+        "task_results",
+        sa.Column("created_at", sa.DateTime(), nullable=True),
+        sa.Column("updated_at", sa.DateTime(), nullable=True),
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column(
+            "key",
+            rally.common.db.sqlalchemy.types.MutableJSONEncodedDict(),
+            nullable=False),
+        sa.Column(
+            "data",
+            rally.common.db.sqlalchemy.types.BigMutableJSONEncodedDict(),
+            nullable=False),
+        sa.Column("task_uuid", sa.String(length=36), nullable=True),
+        sa.ForeignKeyConstraint(["task_uuid"], ["tasks.uuid"], ),
+        sa.PrimaryKeyConstraint("id")
+    )
+
+    op.create_table(
+        "verification_results",
+        sa.Column("created_at", sa.DateTime(), nullable=True),
+        sa.Column("updated_at", sa.DateTime(), nullable=True),
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("verification_uuid", sa.String(length=36), nullable=True),
+        sa.Column(
+            "data",
+            rally.common.db.sqlalchemy.types.BigMutableJSONEncodedDict(),
+            nullable=False),
+        sa.ForeignKeyConstraint(["verification_uuid"], ["verifications.uuid"]),
+        sa.PrimaryKeyConstraint("id")
+    )
+    # end Alembic commands
+
+
+def downgrade():
+    # commands auto generated by Alembic - please adjust!
+    op.drop_table("verification_results")
+    op.drop_table("task_results")
+    op.drop_index("verification_uuid", table_name="verifications")
+    op.drop_table("verifications")
+    op.drop_index("task_uuid", table_name="tasks")
+    op.drop_index("task_status", table_name="tasks")
+    op.drop_index("task_deployment", table_name="tasks")
+    op.drop_table("tasks")
+    op.drop_index("resource_type", table_name="resources")
+    op.drop_index("resource_provider_name_and_type", table_name="resources")
+    op.drop_index("resource_provider_name", table_name="resources")
+    op.drop_index("resource_deployment_uuid", table_name="resources")
+    op.drop_table("resources")
+    op.drop_table("workers")
+    op.drop_index("deployment_uuid", table_name="deployments")
+    op.drop_index("deployment_parent_uuid", table_name="deployments")
+    op.drop_table("deployments")
+    # end Alembic commands

rally/common/db/sqlalchemy/models.py

@@ -235,12 +235,6 @@ class Worker(BASE, RallyBase):
     hostname = sa.Column(sa.String(255))
 
 
-def create_db():
-    from rally.common.db.sqlalchemy import api as sa_api
-
-    BASE.metadata.create_all(sa_api.get_engine())
-
-
 # TODO(boris-42): Remove it after oslo.db > 1.4.1 will be released.
 def drop_all_objects(engine):
     """Drop all database objects.

requirements.txt

@@ -1,6 +1,7 @@
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
+alembic>=0.8.0 # MIT
 Babel>=1.3 # BSD
 boto>=2.32.1 # MIT
 decorator>=3.4.0 # BSD

tests/unit/cli/test_manage.py

@@ -36,8 +36,37 @@ class DBCommandsTestCase(test.TestCase):
         super(DBCommandsTestCase, self).setUp()
         self.db_commands = manage.DBCommands()
 
+    @mock.patch("rally.cli.manage.envutils")
     @mock.patch("rally.cli.manage.db")
-    def test_recreate(self, mock_db):
+    def test_recreate(self, mock_db, mock_envutils):
         self.db_commands.recreate()
-        calls = [mock.call.db_drop(), mock.call.db_create()]
+        db_calls = [mock.call.schema_cleanup(),
+                    mock.call.schema_create()]
+        self.assertEqual(db_calls, mock_db.mock_calls)
+        envutils_calls = [mock.call.clear_env()]
+        self.assertEqual(envutils_calls, mock_envutils.mock_calls)
+
+    @mock.patch("rally.cli.manage.db")
+    def test_create(self, mock_db):
+        self.db_commands.create()
+        calls = [mock.call.schema_create()]
         self.assertEqual(calls, mock_db.mock_calls)
+
+    @mock.patch("rally.cli.manage.db")
+    def test_upgrade(self, mock_db):
+        self.db_commands.upgrade()
+        calls = [mock.call.schema_upgrade()]
+        self.assertEqual(calls, mock_db.mock_calls)
+
+    @mock.patch("rally.cli.manage.db")
+    def test_downgrade(self, mock_db):
+        revision = mock.MagicMock()
+        self.db_commands.downgrade(revision)
+        calls = [mock.call.schema_downgrade(revision)]
+        self.assertEqual(calls, mock_db.mock_calls)
+
+    @mock.patch("rally.cli.manage.db")
+    def test_revision(self, mock_db):
+        self.db_commands.revision()
+        calls = [mock.call.schema_revision()]
+        mock_db.assert_has_calls(calls)

tests/unit/common/db/test_migrations.py

@@ -0,0 +1,204 @@
+# Copyright (c) 2016 Mirantis Inc.
+# All Rights Reserved.
+#
+#    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 DB migration."""
+
+
+import pprint
+
+import alembic
+import mock
+from oslo_db.sqlalchemy import test_migrations
+import six
+import sqlalchemy as sa
+
+import rally
+from rally.common import db
+from rally.common.db.sqlalchemy import api
+from rally.common.db.sqlalchemy import models
+from tests.unit import test as rtest
+
+
+class MigrationTestCase(rtest.DBTestCase,
+                        test_migrations.ModelsMigrationsSync):
+    """Test for checking of equality models state and migrations.
+
+    For the opportunistic testing you need to set up a db named
+    'openstack_citest' with user 'openstack_citest' and password
+    'openstack_citest' on localhost.
+    The test will then use that db and user/password combo to run the tests.
+
+    For PostgreSQL on Ubuntu this can be done with the following commands::
+
+        sudo -u postgres psql
+        postgres=# create user openstack_citest with createdb login password
+                  'openstack_citest';
+        postgres=# create database openstack_citest with owner
+                   openstack_citest;
+
+    For MySQL on Ubuntu this can be done with the following commands::
+
+        mysql -u root
+        >create database openstack_citest;
+        >grant all privileges on openstack_citest.* to
+         openstack_citest@localhost identified by 'openstack_citest';
+
+    Output is a list that contains information about differences between db and
+    models. Output example::
+
+       [('add_table',
+         Table('bat', MetaData(bind=None),
+               Column('info', String(), table=<bat>), schema=None)),
+        ('remove_table',
+         Table(u'bar', MetaData(bind=None),
+               Column(u'data', VARCHAR(), table=<bar>), schema=None)),
+        ('add_column',
+         None,
+         'foo',
+         Column('data', Integer(), table=<foo>)),
+        ('remove_column',
+         None,
+         'foo',
+         Column(u'old_data', VARCHAR(), table=None)),
+        [('modify_nullable',
+          None,
+          'foo',
+          u'x',
+          {'existing_server_default': None,
+          'existing_type': INTEGER()},
+          True,
+          False)]]
+
+    * ``remove_*`` means that there is extra table/column/constraint in db;
+
+    * ``add_*`` means that it is missing in db;
+
+    * ``modify_*`` means that on column in db is set wrong
+      type/nullable/server_default. Element contains information:
+
+        - what should be modified,
+        - schema,
+        - table,
+        - column,
+        - existing correct column parameters,
+        - right value,
+        - wrong value.
+    """
+
+    def setUp(self):
+        # we change DB metadata in tests so we reload
+        # models to refresh the metadata to it's original state
+        six.moves.reload_module(rally.common.db.sqlalchemy.models)
+        super(MigrationTestCase, self).setUp()
+        self.alembic_config = api._alembic_config()
+        self.engine = api.get_engine()
+        # remove everything from DB and stamp it as 'base'
+        # so that migration (i.e. upgrade up to 'head')
+        # will actually take place
+        db.schema_cleanup()
+        db.schema_stamp("base")
+
+    def db_sync(self, engine):
+        db.schema_upgrade()
+
+    def get_engine(self):
+        return self.engine
+
+    def get_metadata(self):
+        return models.BASE.metadata
+
+    def include_object(self, object_, name, type_, reflected, compare_to):
+        if type_ == "table" and name == "alembic_version":
+                return False
+
+        return super(MigrationTestCase, self).include_object(
+            object_, name, type_, reflected, compare_to)
+
+    def _create_fake_model(self, table_name):
+        type(
+            "FakeModel",
+            (models.BASE, models.RallyBase),
+            {"__tablename__": table_name,
+             "id": sa.Column(sa.Integer, primary_key=True,
+                             autoincrement=True)}
+        )
+
+    def _get_metadata_diff(self):
+        with self.get_engine().connect() as conn:
+            opts = {
+                "include_object": self.include_object,
+                "compare_type": self.compare_type,
+                "compare_server_default": self.compare_server_default,
+            }
+            mc = alembic.migration.MigrationContext.configure(conn, opts=opts)
+
+            # compare schemas and fail with diff, if it"s not empty
+            diff = self.filter_metadata_diff(
+                alembic.autogenerate.compare_metadata(mc, self.get_metadata()))
+
+        return diff
+
+    @mock.patch("rally.common.db.sqlalchemy.api.Connection.schema_stamp")
+    def test_models_sync(self, mock_connection_schema_stamp):
+        # drop all tables after a test run
+        self.addCleanup(db.schema_cleanup)
+
+        # run migration scripts
+        self.db_sync(self.get_engine())
+
+        diff = self._get_metadata_diff()
+        if diff:
+            msg = pprint.pformat(diff, indent=2, width=20)
+            self.fail(
+                "Models and migration scripts aren't in sync:\n%s" % msg)
+
+    @mock.patch("rally.common.db.sqlalchemy.api.Connection.schema_stamp")
+    def test_models_sync_negative__missing_table_in_script(
+            self, mock_connection_schema_stamp):
+        # drop all tables after a test run
+        self.addCleanup(db.schema_cleanup)
+
+        self._create_fake_model("fake_model")
+
+        # run migration scripts
+        self.db_sync(self.get_engine())
+
+        diff = self._get_metadata_diff()
+
+        self.assertEqual(1, len(diff))
+        action, object = diff[0]
+        self.assertEqual("add_table", action)
+        self.assertIsInstance(object, sa.Table)
+        self.assertEqual("fake_model", object.name)
+
+    @mock.patch("rally.common.db.sqlalchemy.api.Connection.schema_stamp")
+    def test_models_sync_negative__missing_model_in_metadata(
+            self, mock_connection_schema_stamp):
+        # drop all tables after a test run
+        self.addCleanup(db.schema_cleanup)
+
+        table = self.get_metadata().tables["workers"]
+        self.get_metadata().remove(table)
+
+        # run migration scripts
+        self.db_sync(self.get_engine())
+
+        diff = self._get_metadata_diff()
+
+        self.assertEqual(1, len(diff))
+        action, object = diff[0]
+        self.assertEqual("remove_table", action)
+        self.assertIsInstance(object, sa.Table)
+        self.assertEqual("workers", object.name)

tests/unit/test.py

@@ -31,10 +31,10 @@ class DatabaseFixture(fixture.Config):
     def setUp(self):
         super(DatabaseFixture, self).setUp()
         db_url = os.environ.get("RALLY_UNITTEST_DB_URL", "sqlite://")
-        db.db_cleanup()
+        db.engine_reset()
         self.conf.set_default("connection", db_url, group="database")
-        db.db_drop()
-        db.db_create()
+        db.schema_cleanup()
+        db.schema_create()
 
 
 class TestCase(base.BaseTestCase):