From 6da781734ab55eb8840b20964fcbd65b7bc25a5a Mon Sep 17 00:00:00 2001
From: Mike Fedosin <mfedosin@gmail.com>
Date: Tue, 3 Jan 2017 23:12:31 +0300
Subject: [PATCH] Allow to specify data and lock apis with config

Change-Id: Ib8aecda22b89218a3106b301ec56baf081b164bf
---
 glare/common/wsgi.py  | 28 ++++++++++++++++++++++++++++
 glare/engine.py       |  4 ++--
 glare/objects/base.py | 16 +++-------------
 glare/opts.py         |  1 +
 4 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/glare/common/wsgi.py b/glare/common/wsgi.py
index d56dc19..a706f04 100644
--- a/glare/common/wsgi.py
+++ b/glare/common/wsgi.py
@@ -104,6 +104,33 @@ eventlet_opts = [
                       'wait forever.')),
 ]
 
+data_api_opts = [
+    cfg.StrOpt('data_api',
+               default='glare.db.artifact_api.ArtifactAPI',
+               help=("""
+Python class path of data access API.
+
+Specifies the path to the API to use for accessing the data model.
+This option determines how the artifact catalog data will be accessed.
+
+If this option is set to ``glare.db.artifact_api.ArtifactAPI`` then
+the artifact catalog data is stored in and read from the database via the
+SQLAlchemy Core and ORM APIs.
+""")),
+    cfg.StrOpt('lock_api',
+               default='glare.db.artifact_api.ArtifactLockApi',
+               help=("""
+Python class path of API for setting locks on artifacts.
+
+Specifies the path to the API to use for locking.
+This option determines how the locking will be accessed.
+
+If this option is set to ``glare.db.artifact_api.ArtifactLockApi``
+then the locks are stored in and read from the database via the
+SQLAlchemy Core and ORM APIs.
+"""))
+]
+
 
 LOG = logging.getLogger(__name__)
 
@@ -111,6 +138,7 @@ CONF = cfg.CONF
 CONF.register_opts(bind_opts)
 CONF.register_opts(socket_opts)
 CONF.register_opts(eventlet_opts)
+CONF.register_opts(data_api_opts)
 profiler_opts.set_defaults(CONF)
 
 ASYNC_EVENTLET_THREAD_POOL_LIST = []
diff --git a/glare/engine.py b/glare/engine.py
index 8b29bc8..af3e378 100644
--- a/glare/engine.py
+++ b/glare/engine.py
@@ -19,12 +19,12 @@ import jsonpatch
 from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import excutils
+from oslo_utils import importutils
 
 from glare.common import exception
 from glare.common import policy
 from glare.common import store_api
 from glare.common import utils
-from glare.db import artifact_api
 from glare.i18n import _, _LI
 from glare import locking
 from glare.notification import Notifier
@@ -52,7 +52,7 @@ class Engine(object):
 
     registry = glare_registry.ArtifactRegistry
     registry.register_all_artifacts()
-    lock_engine = locking.LockEngine(artifact_api.ArtifactLockApi())
+    lock_engine = locking.LockEngine(importutils.import_class(CONF.lock_api)())
 
     @classmethod
     def _get_schemas(cls, reg):
diff --git a/glare/objects/base.py b/glare/objects/base.py
index 43c930a..d52fd47 100644
--- a/glare/objects/base.py
+++ b/glare/objects/base.py
@@ -18,6 +18,7 @@ import uuid
 
 from oslo_config import cfg
 from oslo_log import log as logging
+from oslo_utils import importutils
 from oslo_utils import timeutils
 from oslo_versionedobjects import base
 from oslo_versionedobjects import fields
@@ -27,7 +28,6 @@ import six.moves.urllib.request as urlrequest
 from glare.common import exception
 from glare.common import store_api
 from glare.common import utils
-from glare.db import artifact_api
 from glare import locking
 from glare.i18n import _, _LI
 from glare.objects.meta import attribute
@@ -233,24 +233,14 @@ class BaseArtifact(base.VersionedObject):
 
     _DB_API = None
 
-    @classmethod
-    def init_db_api(cls):
-        """Provide initialized db api to interact with artifact database.
-
-        To interact with database each artifact type must provide an api
-        to execute db operations with artifacts.
-        :return: subtype of glare.db.api.BaseDBAPI
-        """
-        return artifact_api.ArtifactAPI(cls)
-
     @classproperty
     def db_api(cls):
         """Return current database API"""
         if cls._DB_API is None:
-            cls._DB_API = cls.init_db_api()
+            cls._DB_API = importutils.import_class(CONF.data_api)(cls)
         return cls._DB_API
 
-    lock_engine = locking.LockEngine(artifact_api.ArtifactLockApi())
+    lock_engine = locking.LockEngine(importutils.import_class(CONF.lock_api)())
 
     @classmethod
     def _lock_version(cls, context, values):
diff --git a/glare/opts.py b/glare/opts.py
index 0220f30..065251f 100644
--- a/glare/opts.py
+++ b/glare/opts.py
@@ -37,6 +37,7 @@ _artifacts_opts = [
         glare.api.versions.versions_opts,
         glare.common.config.common_opts,
         glare.common.wsgi.bind_opts,
+        glare.common.wsgi.data_api_opts,
         glare.common.wsgi.eventlet_opts,
         glare.common.wsgi.socket_opts,
         glare.notification.notifier_opts,