openstack/placement
Code Issues Proposed changes

Suppress not image properties for image metadata from volume

Browse Source 
Currently image metadata restored from a bootable volume has some
properties which are not properties of an original image. But Nova
stores these properties into system metadata of an instance booted from
the volume and into properties of snapshot image of the instance. This
leads to consuming of waste DB space, increases traffic with DB, and
confuses end users by unexpected image properties of instnace snapshot.

The reason is that Cinder stores image attributes (id, name, checksum,
etc) as volume image metadata together with true image metadata. Then
Nova loads this metadata and uses it as properties of image metadata as
is, with no modification.

This patch removes this artifical properties from loaded volume image
metadata.

Related-Bug: #1439819
Change-Id: Ic1155449aa47170ffd4e6e87e50de0a4cb5732da
This commit is contained in:
Feodor Tersin
2015-07-23 11:11:59 +03:00
parent a8ece7bec8
commit e2e371bcdd
1 changed files with 17 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
nova/utils.py
View File

@@ -18,6 +18,7 @@
"""Utilities and helper functions."""
import contextlib
import copy
import datetime
import errno
import functools
@@ -172,6 +173,12 @@ SM_SKIP_KEYS = (
# Modern names
'img_mappings', 'img_block_device_mapping',
)
# Image attributes which Cinder stores in volume image metadata
# as regular properties
VIM_IMAGE_ATTRIBUTES = (
'image_id', 'image_name', 'size', 'checksum',
'container_format', 'disk_format', 'min_ram', 'min_disk',
)
_FILE_CACHE = {}
@@ -1161,21 +1168,23 @@ def get_image_from_system_metadata(system_meta):
def get_image_metadata_from_volume(volume):
properties = volume.get('volume_image_metadata', {})
properties = copy.copy(volume.get('volume_image_metadata', {}))
image_meta = {'properties': properties}
# NOTE(yjiang5): restore the basic attributes
# NOTE(mdbooth): These values come from volume_glance_metadata
# in cinder. This is a simple key/value table, and all values
# are strings. We need to convert them to ints to avoid
# unexpected type errors.
image_meta['min_ram'] = int(properties.get('min_ram', 0))
image_meta['min_disk'] = int(properties.get('min_disk', 0))
# Volume size is no longer related to the original image size,
# so we take it from the volume directly. Cinder creates
# volumes in Gb increments, and stores size in Gb, whereas
# glance reports size in bytes. As we're returning glance
# metadata here, we need to convert it.
image_meta['size'] = volume.get('size', 0) * units.Gi
# NOTE(yjiang5): restore the basic attributes
# NOTE(mdbooth): These values come from volume_glance_metadata
# in cinder. This is a simple key/value table, and all values
# are strings. We need to convert them to ints to avoid
# unexpected type errors.
for attr in VIM_IMAGE_ATTRIBUTES:
val = properties.pop(attr, None)
if attr in ('min_ram', 'min_disk'):
image_meta[attr] = int(val or 0)
# NOTE(yjiang5): Always set the image status as 'active'
# and depends on followed volume_api.check_attach() to
# verify it. This hack should be harmless with that check.