Adding Auth, Compute and Blockstorage composites

* Composites aggregate the various clients, behaviors and configs
   for service subpackages into standalone classes for use in
   tests, data generators, fixtures, etc.
 * Cleans up import clutter by providing a single import for the
   entirety of a service's functionality.
 * Self-authing composites pull the data they need (as defined
   by their configs) from the access data usng the AuthProvider
 * Memoized auth method means that a composite will only ever
   auth once no matter how many times it's instantiated, so logs
   aren't cluttered with multiple, superfluous auth attempts.

Change-Id: I347048f3f5d2f7153181df978f0afa3e65a4f145

cloudcafe/blockstorage/composites.py

@@ -0,0 +1,70 @@
+from cloudcafe.auth.provider import MemoizedAuthServiceComposite
+from cloudcafe.blockstorage.config import BlockStorageConfig
+from cloudcafe.blockstorage.volumes_api.common.config import VolumesAPIConfig
+
+from cloudcafe.blockstorage.volumes_api.v1.config import \
+    VolumesAPIConfig as v1Config
+from cloudcafe.blockstorage.volumes_api.v1.client import \
+    VolumesClient as v1Client
+from cloudcafe.blockstorage.volumes_api.v1.behaviors import \
+    VolumesAPI_Behaviors as v1Behaviors
+
+from cloudcafe.blockstorage.volumes_api.v2.config import \
+    VolumesAPIConfig as v2Config
+from cloudcafe.blockstorage.volumes_api.v2.client import \
+    VolumesClient as v2Client
+from cloudcafe.blockstorage.volumes_api.v2.behaviors import \
+    VolumesAPI_Behaviors as v2Behaviors
+
+
+class _BlockstorageAuthComposite(MemoizedAuthServiceComposite):
+    def __init__(self):
+        self.config = BlockStorageConfig()
+        self.availability_zone = \
+            self.config.availability_zone
+        super(_BlockstorageAuthComposite, self).__init__(
+            self.config.identity_service_name, self.config.region)
+
+
+class _BaseVolumesComposite(object):
+    _config = None
+    _client = None
+    _behaviors = None
+
+    def __init__(self):
+        self.blockstorage_auth = _BlockstorageAuthComposite()
+        self.config = self._config()
+        self.client = self._client(
+            url=self.blockstorage_auth.public_url,
+            auth_token=self.blockstorage_auth.token_id,
+            serialize_format=self.config.serialize_format,
+            deserialize_format=self.config.deserialize_format)
+        self.behaviors = self._behaviors(self.client)
+
+
+#For version specific tests
+class VolumesV1Composite(_BaseVolumesComposite):
+    _config = v1Config
+    _client = v1Client
+    _behaviors = v1Behaviors
+
+
+class VolumesV2Composite(_BaseVolumesComposite):
+    _config = v2Config
+    _client = v2Client
+    _behaviors = v2Behaviors
+
+
+#For version agnostic tests
+class VolumesAutoComposite(object):
+    def __new__(cls):
+        config = VolumesAPIConfig()
+        if config.version_under_test == "1":
+            return VolumesV1Composite()
+        if config.version_under_test == "2":
+            return VolumesV2Composite()
+        else:
+            raise Exception(
+                "VolumesAutoComposite cannot be used unless the "
+                "'version_under_test' attribute of the VolumesAPIConfig"
+                " is set to either '1' or '2'")