config options: centralize section "database" + "api_database"

The config options of the "nova.conf" section "database" and
"api_database" got moved to the new central location
"nova/conf/database.py". Also the database related options which are
in DEFAULT section.

Follow up changes will improve the help texts.

bp centralize-config-options-newton

Change-Id: Iaba9b49490fea4950bb25eed3ba1252db206f3c9

nova/conf/__init__.py

@@ -37,7 +37,7 @@ from nova.conf import consoleauth
 # from nova.conf import cors
 # from nova.conf import cors.subdomain
 from nova.conf import crypto
-# from nova.conf import database
+from nova.conf import database
 # from nova.conf import disk
 from nova.conf import ephemeral_storage
 from nova.conf import floating_ips
@@ -110,7 +110,7 @@ consoleauth.register_opts(CONF)
 # cors.register_opts(CONF)
 # cors.subdomain.register_opts(CONF)
 crypto.register_opts(CONF)
-# database.register_opts(CONF)
+database.register_opts(CONF)
 # disk.register_opts(CONF)
 ephemeral_storage.register_opts(CONF)
 floating_ips.register_opts(CONF)

nova/conf/compute.py

@@ -309,6 +309,23 @@ whenever an RPC call to the compute service is made.
 """),
 ]
 
+db_opts = [
+    cfg.StrOpt('osapi_compute_unique_server_name_scope',
+               default='',
+               help='When set, compute API will consider duplicate hostnames '
+                    'invalid within the specified scope, regardless of case. '
+                    'Should be empty, "project" or "global".'),
+    cfg.BoolOpt('enable_new_services',
+                default=True,
+                help='Services to be added to the available pool on create'),
+    cfg.StrOpt('instance_name_template',
+               default='instance-%08x',
+               help='Template string to be used to generate instance names'),
+    cfg.StrOpt('snapshot_name_template',
+               default='snapshot-%s',
+               help='Template string to be used to generate snapshot names'),
+]
+
 ALL_OPTS = list(itertools.chain(
            compute_opts,
            resource_tracker_opts,
@@ -319,6 +336,7 @@ ALL_OPTS = list(itertools.chain(
            running_deleted_opts,
            instance_cleaning_opts,
            rpcapi_opts,
+           db_opts,
            ))
 
 

nova/conf/database.py

@@ -0,0 +1,106 @@
+# Copyright 2015 OpenStack Foundation
+# 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 oslo_config import cfg
+from oslo_db import options as oslo_db_options
+
+
+# NOTE(sdague): we know of at least 1 instance of out of tree usage
+# for this config in RAX. They used this because of performance issues
+# with some queries. We think the right path forward is fixing the
+# SQLA queries to be more performant for everyone.
+db_driver_opt = cfg.StrOpt(
+        'db_driver',
+        default='nova.db',
+        help='DEPRECATED: The driver to use for database access',
+        deprecated_for_removal=True)
+
+
+# NOTE(markus_z): We cannot simply do:
+# conf.register_opts(oslo_db_options.database_opts, 'api_database')
+# If we reuse a db config option for two different groups ("api_database"
+# and "database") and deprecate or rename a config option in one of these
+# groups, "oslo.config" cannot correctly determine which one to update.
+# That's why we copied & pasted these config options for the "api_database"
+# group here. See commit ba407e3 ("Add support for multiple database engines")
+# for more details.
+api_db_opts = [
+    cfg.StrOpt('connection',
+               help='The SQLAlchemy connection string to use to connect to '
+                    'the Nova API database.',
+               secret=True),
+    cfg.BoolOpt('sqlite_synchronous',
+                default=True,
+                help='If True, SQLite uses synchronous mode.'),
+    cfg.StrOpt('slave_connection',
+               secret=True,
+               help='The SQLAlchemy connection string to use to connect to the'
+                    ' slave database.'),
+    cfg.StrOpt('mysql_sql_mode',
+               default='TRADITIONAL',
+               help='The SQL mode to be used for MySQL sessions. '
+                    'This option, including the default, overrides any '
+                    'server-set SQL mode. To use whatever SQL mode '
+                    'is set by the server configuration, '
+                    'set this to no value. Example: mysql_sql_mode='),
+    cfg.IntOpt('idle_timeout',
+               default=3600,
+               help='Timeout before idle SQL connections are reaped.'),
+    cfg.IntOpt('max_pool_size',
+               help='Maximum number of SQL connections to keep open in a '
+                    'pool.'),
+    cfg.IntOpt('max_retries',
+               default=10,
+               help='Maximum number of database connection retries '
+                    'during startup. Set to -1 to specify an infinite '
+                    'retry count.'),
+    cfg.IntOpt('retry_interval',
+               default=10,
+               help='Interval between retries of opening a SQL connection.'),
+    cfg.IntOpt('max_overflow',
+               help='If set, use this value for max_overflow with '
+                    'SQLAlchemy.'),
+    cfg.IntOpt('connection_debug',
+               default=0,
+               help='Verbosity of SQL debugging information: 0=None, '
+                    '100=Everything.'),
+    cfg.BoolOpt('connection_trace',
+                default=False,
+                help='Add Python stack traces to SQL as comment strings.'),
+    cfg.IntOpt('pool_timeout',
+               help='If set, use this value for pool_timeout with '
+                    'SQLAlchemy.'),
+]
+
+
+def register_opts(conf):
+    conf.register_opts(oslo_db_options.database_opts, 'database')
+    conf.register_opt(db_driver_opt)
+    conf.register_opts(api_db_opts, group='api_database')
+
+
+def list_opts():
+    # NOTE(markus_z): 2016-04-04: If we list the oslo_db_options here, they
+    #                 get emitted twice(!) in the "sample.conf" file. First
+    #                 under the namespace "nova.conf" and second under the
+    #                 namespace "oslo.db". This is due to the setting in file
+    #                 "etc/nova/nova-config-generator.conf". As I think it
+    #                 is useful to have the "oslo.db" namespace information
+    #                 in the "sample.conf" file, I omit the listing of the
+    #                 "oslo_db_options" here.
+    return {'DEFAULT': [db_driver_opt],
+            'api_database': api_db_opts,
+            }

nova/db/api.py

@@ -27,28 +27,15 @@ these objects be simple dictionaries.
 
 """
 
-from oslo_config import cfg
 from oslo_db import concurrency
 from oslo_log import log as logging
 
 from nova.cells import rpcapi as cells_rpcapi
+import nova.conf
 from nova.i18n import _LE
 
 
-db_opts = [
+CONF = nova.conf.CONF
-    cfg.BoolOpt('enable_new_services',
-                default=True,
-                help='Services to be added to the available pool on create'),
-    cfg.StrOpt('instance_name_template',
-               default='instance-%08x',
-               help='Template string to be used to generate instance names'),
-    cfg.StrOpt('snapshot_name_template',
-               default='snapshot-%s',
-               help='Template string to be used to generate snapshot names'),
-]
-
-CONF = cfg.CONF
-CONF.register_opts(db_opts)
 
 _BACKEND_MAPPING = {'sqlalchemy': 'nova.db.sqlalchemy.api'}
 

nova/db/base.py

@@ -16,22 +16,12 @@
 
 """Base class for classes that need modular database access."""
 
-from oslo_config import cfg
 from oslo_utils import importutils
 
-# NOTE(sdague): we know of at least 1 instance of out of tree usage
+import nova.conf
-# for this config in RAX. They used this because of performance issues
-# with some queries. We think the right path forward is fixing the
-# SQLA queries to be more performant for everyone.
-db_driver_opt = cfg.StrOpt(
-    'db_driver',
-    default='nova.db',
-    help='DEPRECATED: The driver to use for database access',
-    deprecated_for_removal=True)
 
 
-CONF = cfg.CONF
+CONF = nova.conf.CONF
-CONF.register_opt(db_driver_opt)
 
 
 class Base(object):

nova/db/sqlalchemy/api.py

@@ -25,10 +25,8 @@ import inspect
 import sys
 import uuid
 
-from oslo_config import cfg
 from oslo_db import api as oslo_db_api
 from oslo_db import exception as db_exc
-from oslo_db import options as oslo_db_options
 from oslo_db.sqlalchemy import enginefacade
 from oslo_db.sqlalchemy import update_match
 from oslo_db.sqlalchemy import utils as sqlalchemyutils
@@ -70,66 +68,9 @@ from nova.objects import fields
 from nova import quota
 from nova import safe_utils
 
-db_opts = [
-    cfg.StrOpt('osapi_compute_unique_server_name_scope',
-               default='',
-               help='When set, compute API will consider duplicate hostnames '
-                    'invalid within the specified scope, regardless of case. '
-                    'Should be empty, "project" or "global".'),
-]
-
-api_db_opts = [
-    cfg.StrOpt('connection',
-               help='The SQLAlchemy connection string to use to connect to '
-                    'the Nova API database.',
-               secret=True),
-    cfg.BoolOpt('sqlite_synchronous',
-                default=True,
-                help='If True, SQLite uses synchronous mode.'),
-    cfg.StrOpt('slave_connection',
-               secret=True,
-               help='The SQLAlchemy connection string to use to connect to the'
-                    ' slave database.'),
-    cfg.StrOpt('mysql_sql_mode',
-               default='TRADITIONAL',
-               help='The SQL mode to be used for MySQL sessions. '
-                    'This option, including the default, overrides any '
-                    'server-set SQL mode. To use whatever SQL mode '
-                    'is set by the server configuration, '
-                    'set this to no value. Example: mysql_sql_mode='),
-    cfg.IntOpt('idle_timeout',
-               default=3600,
-               help='Timeout before idle SQL connections are reaped.'),
-    cfg.IntOpt('max_pool_size',
-               help='Maximum number of SQL connections to keep open in a '
-                    'pool.'),
-    cfg.IntOpt('max_retries',
-               default=10,
-               help='Maximum number of database connection retries '
-                    'during startup. Set to -1 to specify an infinite '
-                    'retry count.'),
-    cfg.IntOpt('retry_interval',
-               default=10,
-               help='Interval between retries of opening a SQL connection.'),
-    cfg.IntOpt('max_overflow',
-               help='If set, use this value for max_overflow with '
-                    'SQLAlchemy.'),
-    cfg.IntOpt('connection_debug',
-               default=0,
-               help='Verbosity of SQL debugging information: 0=None, '
-                    '100=Everything.'),
-    cfg.BoolOpt('connection_trace',
-                default=False,
-                help='Add Python stack traces to SQL as comment strings.'),
-    cfg.IntOpt('pool_timeout',
-               help='If set, use this value for pool_timeout with '
-                    'SQLAlchemy.'),
-]
 
 CONF = nova.conf.CONF
-CONF.register_opts(db_opts)
+
-CONF.register_opts(oslo_db_options.database_opts, 'database')
-CONF.register_opts(api_db_opts, group='api_database')
 
 LOG = logging.getLogger(__name__)
 

nova/opts.py

@@ -21,9 +21,6 @@ import nova.conf
 import nova.console.rpcapi
 import nova.console.serial
 import nova.consoleauth.rpcapi
-import nova.db.api
-import nova.db.base
-import nova.db.sqlalchemy.api
 import nova.exception
 import nova.image.download.file
 import nova.volume
@@ -33,12 +30,7 @@ def list_opts():
     return [
         ('DEFAULT',
          itertools.chain(
-             [nova.db.base.db_driver_opt],
-             nova.db.api.db_opts,
-             nova.db.sqlalchemy.api.db_opts,
              nova.exception.exc_log_opts,
              nova.volume._volume_opts,
          )),
-        ('api_database', nova.db.sqlalchemy.api.api_db_opts),
-        ('database', nova.db.sqlalchemy.api.oslo_db_options.database_opts),
     ]