Check for nova exception.Conflict rather than task_state

When detaching and attaching volumes nova would raise an
exception.Conflict, if attach and detach can't happen. Let's
use that to retry rather than using task_state.

Change-Id: I50904e4254568cd807b9ff18eef482cadb626ce5
Task: 40169
(cherry picked from commit 01c230e793043310614d5b88096476ce0eac2c78)

3 files changed, 25 insertions, 48 deletions

diff --git a/heat/engine/clients/os/nova.py b/heat/engine/clients/os/nova.py
index 78126dd3e..228116ff3 100644
--- a/heat/engine/clients/os/nova.py
+++ b/heat/engine/clients/os/nova.py
@@ -696,7 +696,9 @@ echo -e '%s\tALL=(ALL)\tNOPASSWD: ALL' >> /etc/sudoers
                 volume_id=volume_id,
                 device=device)
         except Exception as ex:
-            if self.is_client_exception(ex):
+            if self.is_conflict(ex):
+                return False
+            elif self.is_client_exception(ex):
                 raise exception.Error(_(
                     "Failed to attach volume %(vol)s to server %(srv)s "
                     "- %(err)s") % {'vol': volume_id,
@@ -711,12 +713,15 @@ echo -e '%s\tALL=(ALL)\tNOPASSWD: ALL' >> /etc/sudoers
         try:
             self.client().volumes.delete_server_volume(server_id, attach_id)
         except Exception as ex:
-            if not (self.is_not_found(ex)
-                    or self.is_bad_request(ex)):
+            if self.is_conflict(ex):
+                return False
+            elif not (self.is_not_found(ex)
+                      or self.is_bad_request(ex)):
                 raise exception.Error(
                     _("Could not detach attachment %(att)s "
                       "from server %(srv)s.") % {'srv': server_id,
                                                  'att': attach_id})
+        return True
 
     def check_detach_volume_complete(self, server_id, attach_id):
         """Check that nova server lost attachment.
diff --git a/heat/engine/resources/openstack/cinder/volume.py b/heat/engine/resources/openstack/cinder/volume.py
index b4e1a84f8..a47efb0c0 100644
--- a/heat/engine/resources/openstack/cinder/volume.py
+++ b/heat/engine/resources/openstack/cinder/volume.py
@@ -508,17 +508,9 @@ class CinderVolume(vb.BaseVolume, sh.SchedulerHintsMixin):
 
     def _detach_volume_to_complete(self, prg_detach):
         if not prg_detach.called:
-            # Waiting OS-EXT-STS:task_state in server to become available for
-            # detach
-            task_state = self.client_plugin('nova').fetch_server_attr(
-                prg_detach.srv_id, 'OS-EXT-STS:task_state')
-            # Wait till out of any resize steps (including resize_finish)
-            if task_state is not None and 'resize' in task_state:
-                prg_detach.called = False
-            else:
-                self.client_plugin('nova').detach_volume(prg_detach.srv_id,
-                                                         prg_detach.attach_id)
-                prg_detach.called = True
+            prg_detach.called = self.client_plugin(
+                'nova').detach_volume(prg_detach.srv_id,
+                                      prg_detach.attach_id)
             return False
         if not prg_detach.cinder_complete:
             prg_detach.cinder_complete = self.client_plugin(
@@ -533,16 +525,8 @@ class CinderVolume(vb.BaseVolume, sh.SchedulerHintsMixin):
 
     def _attach_volume_to_complete(self, prg_attach):
         if not prg_attach.called:
-            # Waiting OS-EXT-STS:task_state in server to become available for
-            # attach
-            task_state = self.client_plugin('nova').fetch_server_attr(
-                prg_attach.srv_id, 'OS-EXT-STS:task_state')
-            # Wait till out of any resize steps (including resize_finish)
-            if task_state is not None and 'resize' in task_state:
-                prg_attach.called = False
-            else:
-                prg_attach.called = self.client_plugin('nova').attach_volume(
-                    prg_attach.srv_id, prg_attach.vol_id, prg_attach.device)
+            prg_attach.called = self.client_plugin('nova').attach_volume(
+                prg_attach.srv_id, prg_attach.vol_id, prg_attach.device)
             return False
         if not prg_attach.complete:
             prg_attach.complete = self.client_plugin(
@@ -768,17 +752,8 @@ class CinderVolumeAttachment(vb.BaseVolumeAttachment):
             prg_detach = progress.VolumeDetachProgress(
                 server_id, volume_id, self.resource_id)
 
-            # Waiting OS-EXT-STS:task_state in server to become available for
-            # detach
-            server = self.client_plugin('nova').fetch_server(server_id)
-            task_state = getattr(server, 'OS-EXT-STS:task_state', None)
-            # Wait till out of any resize steps (including resize_finish)
-            if task_state is not None and 'resize' in task_state:
-                prg_detach.called = False
-            else:
-                self.client_plugin('nova').detach_volume(server_id,
-                                                         self.resource_id)
-                prg_detach.called = True
+            prg_detach.called = self.client_plugin(
+                'nova').detach_volume(server_id, self.resource_id)
 
             if self.VOLUME_ID in prop_diff:
                 volume_id = prop_diff.get(self.VOLUME_ID)
@@ -811,16 +786,8 @@ class CinderVolumeAttachment(vb.BaseVolumeAttachment):
                                                      self.resource_id)
             return False
         if not prg_attach.called:
-            # Waiting OS-EXT-STS:task_state in server to become available for
-            # attach
-            server = self.client_plugin('nova').fetch_server(prg_attach.srv_id)
-            task_state = getattr(server, 'OS-EXT-STS:task_state', None)
-            # Wait till out of any resize steps (including resize_finish)
-            if task_state is not None and 'resize' in task_state:
-                prg_attach.called = False
-            else:
-                prg_attach.called = self.client_plugin('nova').attach_volume(
-                    prg_attach.srv_id, prg_attach.vol_id, prg_attach.device)
+            prg_attach.called = self.client_plugin('nova').attach_volume(
+                prg_attach.srv_id, prg_attach.vol_id, prg_attach.device)
             return False
         if not prg_attach.complete:
             prg_attach.complete = self.client_plugin(
diff --git a/heat/tests/openstack/cinder/test_volume.py b/heat/tests/openstack/cinder/test_volume.py
index 221d6880d..d55159869 100644
--- a/heat/tests/openstack/cinder/test_volume.py
+++ b/heat/tests/openstack/cinder/test_volume.py
@@ -17,6 +17,7 @@ import json
 
 from cinderclient import exceptions as cinder_exp
 import mock
+from novaclient import exceptions as nova_exp
 from oslo_config import cfg
 import six
 
@@ -907,7 +908,6 @@ class CinderVolumeTest(vt_base.VolumeTestCase):
                                      fv1, fva,
                                      vt_base.FakeVolume('available'), fv2])
         self.stub_VolumeConstraint_validate()
-
         # delete script
         self.fc.volumes.get_server_volume.side_effect = [
             fva, fva, fakes_nova.fake_exception()]
@@ -916,10 +916,12 @@ class CinderVolumeTest(vt_base.VolumeTestCase):
         stack = utils.parse_stack(self.t, stack_name=self.stack_name)
 
         self.create_volume(self.t, stack, 'volume')
-
         rsrc = self.create_attachment(self.t, stack, 'attachment')
         prg_detach = mock.MagicMock(cinder_complete=True, nova_complete=True)
         prg_attach = mock.MagicMock(called=False, srv_id='InstanceInResize')
+        self.fc.volumes.create_server_volume.side_effect = [
+            nova_exp.Conflict('409')]
+
         self.assertEqual(False,
                          rsrc.check_update_complete((prg_detach, prg_attach)))
         self.assertEqual(False, prg_attach.called)
@@ -1299,6 +1301,8 @@ class CinderVolumeTest(vt_base.VolumeTestCase):
         self.cinder_fc.volumes.create.return_value = fv
         fv_ready = vt_base.FakeVolume('available', id=fv.id)
         self.cinder_fc.volumes.get.side_effect = [fv, fv_ready]
+        self.fc.volumes.delete_server_volume.side_effect = [
+            nova_exp.Conflict('409')]
         self.t['resources']['volume']['properties'].update({
             'volume_type': 'lvm',
         })
@@ -1338,7 +1342,8 @@ class CinderVolumeTest(vt_base.VolumeTestCase):
         self.cinder_fc.volumes.create.return_value = fv
         fv_ready = vt_base.FakeVolume('available', id=fv.id)
         self.cinder_fc.volumes.get.side_effect = [fv, fv_ready]
-
+        self.fc.volumes.create_server_volume.side_effect = [
+            nova_exp.Conflict('409')]
         self.t['resources']['volume']['properties'].update({
             'volume_type': 'lvm',
         })