Wrong usage of "a"

Wrong usage of "a" in the mesages:
"lookup the instance after a instance_destroy_at_top hits"
"returns the PCI address of a an device"
"will result in a additional lookup to glance for said attr"
"This will ensure that a image is not deleted during the spawn"
"Lock to ensure that the spawn will not try and access a image"
"cleanup the _events_delayed dictionary when a event"
"it will raise a exception.NovaException"
"we need to allocate a ephemeral disk if required"
"this may be a endless loop, so check the id of"

Should be:
"lookup the instance after an instance_destroy_at_top hits"
"returns the PCI address of a device"
"will result in an additional lookup to glance for said attr"
"This will ensure that an image is not deleted during the spawn"
"Lock to ensure that the spawn will not try and access an image"
"cleanup the _events_delayed dictionary when an event"
"it will raise an exception.NovaException"
"we need to allocate an ephemeral disk if required"
"this may be an endless loop, so check the id of"

Totally 10 occasions in Nova base code.

Change-Id: I5d5d2d08ea2dbeba519adba73139061702233f7a

nova/compute/cells_api.py

@@ -247,7 +247,7 @@ class ComputeCellsAPI(compute_api.API):
                                     method_name)
             except exception.InstanceNotFound:
                 # NOTE(melwitt): We can get here if anything tries to
-                # lookup the instance after a instance_destroy_at_top hits.
+                # lookup the instance after an instance_destroy_at_top hits.
                 pass
             return
 

nova/image/glance.py

@@ -631,7 +631,7 @@ def _extract_attributes(image, include_locations=False):
             output[attr] = getattr(image, attr) or 0
         else:
             # NOTE(xarses): Anything that is caught with the default value
-            # will result in a additional lookup to glance for said attr.
+            # will result in an additional lookup to glance for said attr.
             # Notable attributes that could have this issue:
             # disk_format, container_format, name, deleted, checksum
             output[attr] = getattr(image, attr, None)

nova/pci/utils.py

@@ -71,7 +71,7 @@ def get_pci_address_fields(pci_addr):
 
 
 def get_function_by_ifname(ifname):
-    """Given the device name, returns the PCI address of a an device
+    """Given the device name, returns the PCI address of a device
     and returns True if the address in a physical function.
     """
     try:

nova/virt/libvirt/driver.py

@@ -804,7 +804,7 @@ class LibvirtDriver(driver.ComputeDriver):
                 raise loopingcall.LoopingCallDone()
 
             # NOTE(wangpan): If the instance was booted again after destroy,
-            #                this may be a endless loop, so check the id of
+            #                this may be an endless loop, so check the id of
             #                domain here, if it changed and the instance is
             #                still running, we should destroy it again.
             # see https://bugs.launchpad.net/nova/+bug/1111213 for more details

nova/virt/libvirt/host.py

@@ -385,7 +385,7 @@ class Host(object):
         """Emit events - possibly delayed."""
         def event_cleanup(gt, *args, **kwargs):
             """Callback function for greenthread. Called
-            to cleanup the _events_delayed dictionary when a event
+            to cleanup the _events_delayed dictionary when an event
             was called.
             """
             event = args[0]
@@ -599,7 +599,7 @@ class Host(object):
         corresponding to the Nova instance, based on
         its name. If not found it will raise an
         exception.InstanceNotFound exception. On other
-        errors, it will raise a exception.NovaException
+        errors, it will raise an exception.NovaException
         exception.
 
         :returns: a libvirt.Domain object

nova/virt/vmwareapi/imagecache.py

@@ -32,7 +32,7 @@ If an image is used then the timestamps will be deleted.
 When accessing a timestamp we make use of locking. This ensure that aging
 will not delete an image during the spawn operation. When spawning
 the timestamp folder will be locked  and the timestamps will be purged.
-This will ensure that a image is not deleted during the spawn.
+This will ensure that an image is not deleted during the spawn.
 """
 
 from oslo_concurrency import lockutils
@@ -85,7 +85,7 @@ class ImageCacheManager(imagecache.ImageCacheManager):
         # is going to be used now.
         path = self.timestamp_folder_get(cache_root_folder, image_id)
 
-        # Lock to ensure that the spawn will not try and access a image
+        # Lock to ensure that the spawn will not try and access an image
         # that is currently being deleted on the datastore.
         with lockutils.lock(str(path), lock_file_prefix='nova-vmware-ts',
                             external=True):
@@ -148,7 +148,7 @@ class ImageCacheManager(imagecache.ImageCacheManager):
         ds_browser = self._get_ds_browser(datastore.ref)
         for image in unused_images:
             path = self.timestamp_folder_get(ds_path, image)
-            # Lock to ensure that the spawn will not try and access a image
+            # Lock to ensure that the spawn will not try and access an image
             # that is currently being deleted on the datastore.
             with lockutils.lock(str(path), lock_file_prefix='nova-vmware-ts',
                                 external=True):

nova/virt/vmwareapi/vmops.py

@@ -613,7 +613,7 @@ class VMwareVMOps(object):
                                                   size, at, path)
 
         # There may be block devices defined but no ephemerals. In this case
-        # we need to allocate a ephemeral disk if required
+        # we need to allocate an ephemeral disk if required
         if not ephemerals and instance.ephemeral_gb:
             size = instance.ephemeral_gb * units.Mi
             filename = vm_util.get_ephemeral_name(0)