Add support of defining default store for particular artifact type

Change-Id: I142aaa888a7fab7897b6ef73f075b0863ab8ba59

glare/engine.py

@@ -16,6 +16,7 @@
 import copy
 
 import jsonpatch
+from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import excutils
 
@@ -30,6 +31,7 @@ from glare.notification import Notifier
 from glare.objects.meta import fields as glare_fields
 from glare.objects.meta import registry as glare_registry
 
+CONF = cfg.CONF
 LOG = logging.getLogger(__name__)
 
 
@@ -332,8 +334,16 @@ class Engine(object):
 
         # try to perform blob uploading to storage backend
         try:
+            default_store = af.get_default_store(
+                context, af, field_name, blob_key)
+            if default_store not in set(CONF.glance_store.stores):
+                LOG.warn("Incorrect backend configuration - scheme '%s' is not"
+                         " supported. Fallback to default store."
+                         % default_store)
+                default_store = None
             location_uri, size, checksums = store_api.save_blob_to_store(
-                blob_id, fd, context, af.get_max_blob_size(field_name))
+                blob_id, fd, context, af.get_max_blob_size(field_name),
+                default_store)
         except Exception:
             # if upload failed remove blob from db and storage
             with excutils.save_and_reraise_exception(logger=LOG):

glare/objects/base.py

@@ -843,6 +843,10 @@ class BaseArtifact(base.VersionedObject):
     def validate_publish(cls, context, af):
         pass
 
+    @classmethod
+    def get_default_store(cls, context, af, field_name, blob_key):
+        pass
+
     def to_notification(self):
         """Return notification body that can be send to listeners
 

glare/objects/meta/registry.py

@@ -138,6 +138,7 @@ class ArtifactRegistry(vo_base.VersionedObjectRegistry):
         class_attributes = set(vars(type_class).keys())
         common_attrs = class_attributes & base_attributes
         allowed_attributes = ('VERSION', 'fields', 'init_db_api',
+                              'get_default_store',
                               'get_type_name', 'validate_activate',
                               'validate_publish', 'validate_upload',
                               '__doc__', '__module__')