Add attaching state for Volumes

bug 897726 Add "attaching" status for volumes and clear state on error
This closes a gap where multiple calls of attach for the same volume
can happen before the volume is actually attached.

Change-Id: I59d22ceda83729c1a455af9994c9ffec1912e23b

Authors

@@ -106,6 +106,7 @@ Kevin L. Mitchell <kevin.mitchell@rackspace.com>
 Kiall Mac Innes <kiall@managedit.ie>
 Kirill Shileev <kshileev@gmail.com>
 Koji Iida <iida.koji@lab.ntt.co.jp>
+Liam Kelleher  <liam.kelleher@hp.com>
 Likitha Shetty <likitha.shetty@citrix.com>
 Loganathan Parthipan <parthipan@hp.com>
 Lorin Hochstein <lorin@isi.edu>

nova/tests/policy.json

@@ -127,6 +127,8 @@
 
     "volume:attach": [],
     "volume:detach": [],
+    "volume:reserve_volume": [],
+    "volume:unreserve_volume": [],
     "volume:check_attach": [],
     "volume:check_detach": [],
     "volume:initialize_connection": [],

nova/tests/test_compute.py

@@ -3049,12 +3049,16 @@ class ComputeAPITestCase(BaseTestCase):
         def fake_check_attach(*args, **kwargs):
             pass
 
+        def fake_reserve_volume(*args, **kwargs):
+            pass
+
         def fake_volume_get(self, context, volume_id):
             return {'id': volume_id}
 
         self.stubs.Set(nova.volume.api.API, 'get', fake_volume_get)
         self.stubs.Set(nova.volume.api.API, 'check_attach', fake_check_attach)
-
+        self.stubs.Set(nova.volume.api.API, 'reserve_volume',
+                       fake_reserve_volume)
         instance = self._create_fake_instance()
         self.compute_api.attach_volume(self.context, instance, 1, '/dev/vdb')