Add db migrations

This patch adds support for db migrations, it
creates inital migration with higgins_service
table.

Change-Id: I6adad5f1d00e25ca38e9ba592d0d314b1b6cc74f

higgins/db/__init__.py

@@ -13,6 +13,7 @@
 # under the License.
 
 from oslo_config import cfg
+from oslo_db import options
 
 sql_opts = [
     cfg.StrOpt('mysql_engine',
@@ -21,3 +22,4 @@ sql_opts = [
 ]
 
 cfg.CONF.register_opts(sql_opts, 'database')
+options.set_defaults(cfg.CONF)

higgins/db/sqlalchemy/alembic.ini

@@ -0,0 +1,68 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = %(here)s/alembic
+
+# 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

higgins/db/sqlalchemy/alembic/README

@@ -0,0 +1,11 @@
+Please see https://alembic.readthedocs.org/en/latest/index.html for general documentation
+
+To create alembic migrations use:
+$ higgins-db-manage revision --message "description of revision" --autogenerate
+
+Stamp db with most recent migration version, without actually running migrations
+$ higgins-db-manage stamp head
+
+Upgrade can be performed by:
+$ higgins-db-manage upgrade
+$ higgins-db-manage upgrade head

higgins/db/sqlalchemy/alembic/env.py

@@ -0,0 +1,57 @@
+#    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 __future__ import with_statement
+from alembic import context
+from logging.config import fileConfig
+
+from higgins.db.sqlalchemy import api as sqla_api
+from higgins.db.sqlalchemy import models
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+# from myapp import mymodel
+# target_metadata = mymodel.Base.metadata
+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 = sqla_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()

higgins/db/sqlalchemy/alembic/script.py.mako

@@ -0,0 +1,20 @@
+"""${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"}

higgins/db/sqlalchemy/alembic/versions/a9a92eebd9a8_create_table_higgins_service.py

@@ -0,0 +1,48 @@
+#    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_table_higgins_service
+
+Revision ID: a9a92eebd9a8
+Revises:
+Create Date: 2016-05-27 10:53:10.367610
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = 'a9a92eebd9a8'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    op.create_table(
+        'higgins_service',
+        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('report_count', sa.Integer(), nullable=False),
+        sa.Column('host', sa.String(length=255), nullable=True),
+        sa.Column('binary', sa.String(length=255), nullable=True),
+        sa.Column('disabled', sa.Boolean(), nullable=True),
+        sa.Column('disabled_reason', sa.String(length=255), nullable=True),
+        sa.Column('last_seen_up', sa.DateTime(), nullable=True),
+        sa.Column('forced_down', sa.Boolean(), nullable=True),
+        sa.PrimaryKeyConstraint('id'),
+        sa.UniqueConstraint('host', 'binary',
+                            name='uniq_higgins_service0host0binary')
+    )

higgins/db/sqlalchemy/migration.py

@@ -0,0 +1,81 @@
+# Copyright 2010 United States Government as represented by the
+# Administrator of the National Aeronautics and Space Administration.
+# 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.
+
+import os
+
+from oslo_config import cfg
+from oslo_db.sqlalchemy.migration_cli import manager
+
+_MANAGER = None
+
+
+def get_manager():
+    global _MANAGER
+    if not _MANAGER:
+        alembic_path = os.path.abspath(
+            os.path.join(os.path.dirname(__file__), 'alembic.ini'))
+        migrate_path = os.path.abspath(
+            os.path.join(os.path.dirname(__file__), 'alembic'))
+        migration_config = {'alembic_ini_path': alembic_path,
+                            'alembic_repo_path': migrate_path,
+                            'db_url': cfg.CONF.database.connection}
+        _MANAGER = manager.MigrationManager(migration_config)
+
+    return _MANAGER
+
+
+def version():
+    """Current database version.
+
+    :returns: Database version
+    :rtype: string
+    """
+    return get_manager().version()
+
+
+def upgrade(version):
+    """Used for upgrading database.
+
+    :param version: Desired database version
+    :type version: string
+    """
+    version = version or 'head'
+
+    get_manager().upgrade(version)
+
+
+def stamp(revision):
+    """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
+    """
+    get_manager().stamp(revision)
+
+
+def revision(message=None, autogenerate=False):
+    """Creates template for migration.
+
+    :param message: Text that will be used for migration title
+    :type message: string
+    :param autogenerate: If True - generates diff based on current database
+                         state
+    :type autogenerate: bool
+    """
+    return get_manager().revision(message=message, autogenerate=autogenerate)

setup.cfg

@@ -48,6 +48,11 @@ output_file = higgins/locale/higgins.pot
 console_scripts =
     higgins-api = higgins.cmd.api:main
     higgins-conductor = higgins.cmd.conductor:main
+    higgins-db-manage = higgins.cmd.db_manage:main
 
 oslo.config.opts =
     higgins = higgins.opts:list_opts
+
+higgins.database.migration_backend =
+    sqlalchemy = higgins.db.sqlalchemy.migration
+