Fix v2 requests to non-bleeding edge servers

In the case where v2 requests are sent to a server which is not running
head of tree which includes the v2 metadef code some 404 cases need to
be handled to enable standard requests to complete.

This patch aslo improves fetching schemas -- they are now only
fetched as needed.

Change-Id: I8c871f11b909337bd7df19b77e606772dbc634b2
Closes-bug: #1367326

glanceclient/common/utils.py

@@ -21,6 +21,7 @@ import json
 import os
 import re
 import sys
+import threading
 import uuid
 
 import six
@@ -36,6 +37,8 @@ from glanceclient import exc
 from glanceclient.openstack.common import importutils
 from glanceclient.openstack.common import strutils
 
+_memoized_property_lock = threading.Lock()
+
 
 # Decorator for cli-args
 def arg(*args, **kwargs):
@@ -367,3 +370,18 @@ def integrity_iter(iter, checksum):
         raise IOError(errno.EPIPE,
                       'Corrupt image download. Checksum was %s expected %s' %
                       (md5sum, checksum))
+
+
+def memoized_property(fn):
+    attr_name = '_lazy_once_' + fn.__name__
+
+    @property
+    def _memoized_property(self):
+        if hasattr(self, attr_name):
+            return getattr(self, attr_name)
+        else:
+            with _memoized_property_lock:
+                if not hasattr(self, attr_name):
+                    setattr(self, attr_name, fn(self))
+            return getattr(self, attr_name)
+    return _memoized_property

glanceclient/v2/client.py

@@ -13,7 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import warlock
 
 from glanceclient.common import http
 from glanceclient.common import utils
@@ -38,50 +37,21 @@ class Client(object):
         self.http_client = http.HTTPClient(utils.strip_version(endpoint),
                                            *args, **kwargs)
         self.schemas = schemas.Controller(self.http_client)
-        image_model = self._get_image_model()
-        self.images = images.Controller(self.http_client,
-                                        image_model)
-        self.image_tags = image_tags.Controller(self.http_client, image_model)
+
+        self.images = images.Controller(self.http_client, self.schemas)
+        self.image_tags = image_tags.Controller(self.http_client,
+                                                self.schemas)
         self.image_members = image_members.Controller(self.http_client,
-                                                      self._get_member_model())
+                                                      self.schemas)
 
-        resource_type_model = self._get_metadefs_resource_type_model()
         self.metadefs_resource_type = (
-            metadefs.ResourceTypeController(self.http_client,
-                                            resource_type_model))
+            metadefs.ResourceTypeController(self.http_client, self.schemas))
 
-        property_model = self._get_metadefs_property_model()
         self.metadefs_property = (
-            metadefs.PropertyController(self.http_client, property_model))
+            metadefs.PropertyController(self.http_client, self.schemas))
 
-        object_model = self._get_metadefs_object_model()
         self.metadefs_object = (
-            metadefs.ObjectController(self.http_client, object_model))
+            metadefs.ObjectController(self.http_client, self.schemas))
 
-        namespace_model = self._get_metadefs_namespace_model()
         self.metadefs_namespace = (
-            metadefs.NamespaceController(self.http_client, namespace_model))
-
-    def _get_image_model(self):
-        schema = self.schemas.get('image')
-        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
-
-    def _get_member_model(self):
-        schema = self.schemas.get('member')
-        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
-
-    def _get_metadefs_namespace_model(self):
-        schema = self.schemas.get('metadefs/namespace')
-        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
-
-    def _get_metadefs_resource_type_model(self):
-        schema = self.schemas.get('metadefs/resource_type')
-        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
-
-    def _get_metadefs_property_model(self):
-        schema = self.schemas.get('metadefs/property')
-        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
-
-    def _get_metadefs_object_model(self):
-        schema = self.schemas.get('metadefs/object')
-        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
+            metadefs.NamespaceController(self.http_client, self.schemas))

glanceclient/v2/image_members.py

@@ -13,11 +13,21 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import warlock
+
+from glanceclient.common import utils
+from glanceclient.v2 import schemas
+
 
 class Controller(object):
-    def __init__(self, http_client, model):
+    def __init__(self, http_client, schema_client):
         self.http_client = http_client
-        self.model = model
+        self.schema_client = schema_client
+
+    @utils.memoized_property
+    def model(self):
+        schema = self.schema_client.get('member')
+        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
 
     def list(self, image_id):
         url = '/v2/images/%s/members' % image_id

glanceclient/v2/image_tags.py

@@ -13,11 +13,21 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import warlock
+
+from glanceclient.common import utils
+from glanceclient.v2 import schemas
+
 
 class Controller(object):
-    def __init__(self, http_client, model):
+    def __init__(self, http_client, schema_client):
         self.http_client = http_client
-        self.model = model
+        self.schema_client = schema_client
+
+    @utils.memoized_property
+    def model(self):
+        schema = self.schema_client.get('image')
+        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
 
     def update(self, image_id, tag_value):
         """

glanceclient/v2/images.py

@@ -21,14 +21,20 @@ import warlock
 from glanceclient.common import utils
 from glanceclient import exc
 from glanceclient.openstack.common import strutils
+from glanceclient.v2 import schemas
 
 DEFAULT_PAGE_SIZE = 20
 
 
 class Controller(object):
-    def __init__(self, http_client, model):
+    def __init__(self, http_client, schema_client):
         self.http_client = http_client
-        self.model = model
+        self.schema_client = schema_client
+
+    @utils.memoized_property
+    def model(self):
+        schema = self.schema_client.get('image')
+        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
 
     def list(self, **kwargs):
         """Retrieve a listing of Image objects

glanceclient/v2/metadefs.py

@@ -19,14 +19,20 @@ import warlock
 
 from glanceclient.common import utils
 from glanceclient.openstack.common import strutils
+from glanceclient.v2 import schemas
 
 DEFAULT_PAGE_SIZE = 20
 
 
 class NamespaceController(object):
-    def __init__(self, http_client, model):
+    def __init__(self, http_client, schema_client):
         self.http_client = http_client
-        self.model = model
+        self.schema_client = schema_client
+
+    @utils.memoized_property
+    def model(self):
+        schema = self.schema_client.get('metadefs/namespace')
+        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
 
     def create(self, **kwargs):
         """Create a namespace.
@@ -75,7 +81,7 @@ class NamespaceController(object):
 
         url = '/v2/metadefs/namespaces/{0}{1}'.format(namespace, query_params)
         resp, body = self.http_client.get(url)
-        #NOTE(bcwaldon): remove 'self' for now until we have an elegant
+        # NOTE(bcwaldon): remove 'self' for now until we have an elegant
         # way to pass it into the model constructor without conflict
         body.pop('self', None)
         return self.model(**body)
@@ -141,9 +147,14 @@ class NamespaceController(object):
 
 
 class ResourceTypeController(object):
-    def __init__(self, http_client, model):
+    def __init__(self, http_client, schema_client):
         self.http_client = http_client
-        self.model = model
+        self.schema_client = schema_client
+
+    @utils.memoized_property
+    def model(self):
+        schema = self.schema_client.get('metadefs/resource_type')
+        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
 
     def associate(self, namespace, **kwargs):
         """Associate a resource type with a namespace."""
@@ -184,9 +195,14 @@ class ResourceTypeController(object):
 
 
 class PropertyController(object):
-    def __init__(self, http_client, model):
+    def __init__(self, http_client, schema_client):
         self.http_client = http_client
-        self.model = model
+        self.schema_client = schema_client
+
+    @utils.memoized_property
+    def model(self):
+        schema = self.schema_client.get('metadefs/property')
+        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
 
     def create(self, namespace, **kwargs):
         """Create a property.
@@ -259,9 +275,14 @@ class PropertyController(object):
 
 
 class ObjectController(object):
-    def __init__(self, http_client, model):
+    def __init__(self, http_client, schema_client):
         self.http_client = http_client
-        self.model = model
+        self.schema_client = schema_client
+
+    @utils.memoized_property
+    def model(self):
+        schema = self.schema_client.get('metadefs/object')
+        return warlock.model_factory(schema.raw(), schemas.SchemaBasedModel)
 
     def create(self, namespace, **kwargs):
         """Create an object.