Files
compute-hyperv/hyperv/nova/imagecache.py
Claudiu Belu cb34a86abf Fixes minor issues
Fix some word spellings in messages.
Do not log twice with different level.
config options: use nova.conf.
Remove unused CONF imports.
Remove unused logging import and LOG global var.
Add transitional support for migrate data objects.

Change-Id: I34006a82c134398f17512de7e7b6c52980460521
2016-02-28 22:45:54 +00:00

250 lines
9.8 KiB
Python

# Copyright 2013 Cloudbase Solutions Srl
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""
Image caching and management.
"""
import os
import re
import nova.conf
from nova import exception
from nova import utils
from nova.virt import imagecache
from nova.virt import images
from os_win import utilsfactory
from oslo_log import log as logging
from oslo_utils import excutils
from oslo_utils import units
from oslo_utils import uuidutils
from hyperv.i18n import _
from hyperv.nova import pathutils
LOG = logging.getLogger(__name__)
CONF = nova.conf.CONF
CONF.import_opt('use_cow_images', 'nova.virt.driver')
CONF.import_opt('instances_path', 'nova.compute.manager')
CONF.import_opt('remove_unused_original_minimum_age_seconds',
'nova.virt.imagecache')
def synchronize_with_path(f):
def wrapper(self, image_path):
@utils.synchronized(image_path)
def inner():
return f(self, image_path)
return inner()
return wrapper
class ImageCache(imagecache.ImageCacheManager):
def __init__(self):
super(ImageCache, self).__init__()
self._pathutils = pathutils.PathUtils()
self._vhdutils = utilsfactory.get_vhdutils()
self.used_images = []
self.unexplained_images = []
self.originals = []
def _get_root_vhd_size_gb(self, instance):
if instance.old_flavor:
return instance.old_flavor.root_gb
else:
return instance.root_gb
def _resize_and_cache_vhd(self, instance, vhd_path):
vhd_size = self._vhdutils.get_vhd_size(vhd_path)['VirtualSize']
root_vhd_size_gb = self._get_root_vhd_size_gb(instance)
root_vhd_size = root_vhd_size_gb * units.Gi
root_vhd_internal_size = (
self._vhdutils.get_internal_vhd_size_by_file_size(
vhd_path, root_vhd_size))
if root_vhd_internal_size < vhd_size:
raise exception.FlavorDiskSmallerThanImage(
flavor_size=root_vhd_size, image_size=vhd_size)
if root_vhd_internal_size > vhd_size:
path_parts = os.path.splitext(vhd_path)
resized_vhd_path = '%s_%s%s' % (path_parts[0],
root_vhd_size_gb,
path_parts[1])
@utils.synchronized(resized_vhd_path)
def copy_and_resize_vhd():
if not self._pathutils.exists(resized_vhd_path):
try:
LOG.debug("Copying VHD %(vhd_path)s to "
"%(resized_vhd_path)s",
{'vhd_path': vhd_path,
'resized_vhd_path': resized_vhd_path})
self._pathutils.copyfile(vhd_path, resized_vhd_path)
LOG.debug("Resizing VHD %(resized_vhd_path)s to new "
"size %(root_vhd_size)s",
{'resized_vhd_path': resized_vhd_path,
'root_vhd_size': root_vhd_size})
self._vhdutils.resize_vhd(resized_vhd_path,
root_vhd_internal_size,
is_file_max_size=False)
except Exception:
with excutils.save_and_reraise_exception():
if self._pathutils.exists(resized_vhd_path):
self._pathutils.remove(resized_vhd_path)
copy_and_resize_vhd()
return resized_vhd_path
def get_cached_image(self, context, instance, rescue_image_id=None):
image_id = rescue_image_id or instance.image_ref
image_type = instance.system_metadata['image_disk_format']
base_image_dir = self._pathutils.get_base_vhd_dir()
base_image_path = os.path.join(base_image_dir, image_id)
@utils.synchronized(base_image_path)
def fetch_image_if_not_existing():
image_path = None
for format_ext in ['vhd', 'vhdx', 'iso']:
test_path = base_image_path + '.' + format_ext
if self._pathutils.exists(test_path):
image_path = test_path
self._update_image_timestamp(image_id)
break
if not image_path:
try:
images.fetch(context, image_id, base_image_path,
instance.user_id,
instance.project_id)
if image_type == 'iso':
format_ext = 'iso'
else:
format_ext = self._vhdutils.get_vhd_format(
base_image_path)
image_path = base_image_path + '.' + format_ext.lower()
self._pathutils.rename(base_image_path, image_path)
except Exception:
with excutils.save_and_reraise_exception():
if self._pathutils.exists(base_image_path):
self._pathutils.remove(base_image_path)
return image_path
image_path = fetch_image_if_not_existing()
# Note: rescue images are not resized.
is_vhd = image_path.split('.')[-1].lower() == 'vhd'
if (CONF.use_cow_images and is_vhd and not rescue_image_id):
# Resize the base VHD image as it's not possible to resize a
# differencing VHD. This does not apply to VHDX images.
resized_image_path = self._resize_and_cache_vhd(instance,
image_path)
if resized_image_path:
return resized_image_path
if rescue_image_id:
self._verify_rescue_image(instance, rescue_image_id, image_path)
return image_path
def _verify_rescue_image(self, instance, rescue_image_id,
rescue_image_path):
rescue_image_info = self._vhdutils.get_vhd_info(rescue_image_path)
rescue_image_size = rescue_image_info['VirtualSize']
flavor_disk_size = instance.root_gb * units.Gi
if rescue_image_size > flavor_disk_size:
err_msg = _('Using a rescue image bigger than the instance '
'flavor disk size is not allowed. '
'Rescue image size: %(rescue_image_size)s. '
'Flavor disk size:%(flavor_disk_size)s. '
'Rescue image id %(rescue_image_id)s.')
raise exception.FlavorDiskSmallerThanImage(err_msg %
{'rescue_image_size': rescue_image_size,
'flavor_disk_size': flavor_disk_size,
'rescue_image_id': rescue_image_id})
def get_image_details(self, context, instance):
image_id = instance.image_ref
return images.get_info(context, image_id)
def _age_and_verify_cached_images(self, context, all_instances, base_dir):
for img in self.originals:
if img in self.used_images:
# change the timestamp on the image so as to reflect the last
# time it was used
self._update_image_timestamp(img)
else:
self._remove_if_old_image(img)
def _update_image_timestamp(self, image_name):
backing_files = self._get_image_backing_files(image_name)
for img in backing_files:
os.utime(img, None)
def _get_image_backing_files(self, image_name):
backing_files = [self._pathutils.lookup_image_basepath(image_name)]
resize_re = re.compile('%s_[0-9]+$' % image_name)
for img in self.unexplained_images:
match = resize_re.match(img)
if match:
backing_files.append(
self._pathutils.lookup_image_basepath(img))
return backing_files
def _remove_if_old_image(self, image_name):
max_age_seconds = CONF.remove_unused_original_minimum_age_seconds
backing_files = self._get_image_backing_files(image_name)
for img in backing_files:
age_seconds = self._pathutils.get_age_of_file(img)
if age_seconds > max_age_seconds:
self.remove_old_image(img)
@synchronize_with_path
def remove_old_image(self, img):
self._pathutils.remove(img)
def update(self, context, all_instances):
base_vhd_dir = self._pathutils.get_base_vhd_dir()
running = self._list_running_instances(context, all_instances)
self.used_images = running['used_images'].keys()
all_files = self.list_base_images(base_vhd_dir)
self.originals = all_files['originals']
self.unexplained_images = all_files['unexplained_images']
self._age_and_verify_cached_images(context, all_instances,
base_vhd_dir)
def list_base_images(self, base_dir):
unexplained_images = []
originals = []
for entry in os.listdir(base_dir):
# remove file extension
file_name = os.path.splitext(entry)[0]
if uuidutils.is_uuid_like(file_name):
originals.append(file_name)
else:
unexplained_images.append(file_name)
return {'unexplained_images': unexplained_images,
'originals': originals}