/usr/lib/python2.6/site-packages/oslo_utils
Edit: /usr/lib/python2.6/site-packages/oslo_utils/imageutils.py (6640B)
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
# Copyright (c) 2010 Citrix Systems, Inc.
#
# 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.
"""
Helper methods to deal with images.
.. versionadded:: 3.1
"""
import re
from oslo_utils._i18n import _
from oslo_utils import strutils
class QemuImgInfo(object):
"""Parse Qemu image information from command `qemu-img info`'s output.
The instance of :class:`QemuImgInfo` has properties: `image`,
`backing_file`, `file_format`, `virtual_size`, `cluster_size`,
`disk_size`, `snapshots` and `encrypted`.
"""
BACKING_FILE_RE = re.compile((r"^(.*?)\s*\(actual\s+path\s*:"
r"\s+(.*?)\)\s*$"), re.I)
TOP_LEVEL_RE = re.compile(r"^([\w\d\s\_\-]+):(.*)$")
SIZE_RE = re.compile(r"(\d*\.?\d+)(\w+)?(\s*\(\s*(\d+)\s+bytes\s*\))?",
re.I)
def __init__(self, cmd_output=None):
details = self._parse(cmd_output or '')
self.image = details.get('image')
self.backing_file = details.get('backing_file')
self.file_format = details.get('file_format')
self.virtual_size = details.get('virtual_size')
self.cluster_size = details.get('cluster_size')
self.disk_size = details.get('disk_size')
self.snapshots = details.get('snapshot_list', [])
self.encrypted = details.get('encrypted')
def __str__(self):
lines = [
'image: %s' % self.image,
'file_format: %s' % self.file_format,
'virtual_size: %s' % self.virtual_size,
'disk_size: %s' % self.disk_size,
'cluster_size: %s' % self.cluster_size,
'backing_file: %s' % self.backing_file,
]
if self.snapshots:
lines.append("snapshots: %s" % self.snapshots)
if self.encrypted:
lines.append("encrypted: %s" % self.encrypted)
return "\n".join(lines)
def _canonicalize(self, field):
# Standardize on underscores/lc/no dash and no spaces
# since qemu seems to have mixed outputs here... and
# this format allows for better integration with python
# - i.e. for usage in kwargs and such...
field = field.lower().strip()
for c in (" ", "-"):
field = field.replace(c, '_')
return field
def _extract_bytes(self, details):
# Replace it with the byte amount
real_size = self.SIZE_RE.search(details)
if not real_size:
raise ValueError(_('Invalid input value "%s".') % details)
magnitude = real_size.group(1)
unit_of_measure = real_size.group(2)
bytes_info = real_size.group(3)
if bytes_info:
return int(real_size.group(4))
elif not unit_of_measure:
return int(magnitude)
return strutils.string_to_bytes('%s%sB' % (magnitude, unit_of_measure),
return_int=True)
def _extract_details(self, root_cmd, root_details, lines_after):
real_details = root_details
if root_cmd == 'backing_file':
# Replace it with the real backing file
backing_match = self.BACKING_FILE_RE.match(root_details)
if backing_match:
real_details = backing_match.group(2).strip()
elif root_cmd in ['virtual_size', 'cluster_size', 'disk_size']:
# Replace it with the byte amount (if we can convert it)
if root_details in ('None', 'unavailable'):
real_details = 0
else:
real_details = self._extract_bytes(root_details)
elif root_cmd == 'file_format':
real_details = real_details.strip().lower()
elif root_cmd == 'snapshot_list':
# Next line should be a header, starting with 'ID'
if not lines_after or not lines_after.pop(0).startswith("ID"):
msg = _("Snapshot list encountered but no header found!")
raise ValueError(msg)
real_details = []
# This is the sprintf pattern we will try to match
# "%-10s%-20s%7s%20s%15s"
# ID TAG VM SIZE DATE VM CLOCK (current header)
while lines_after:
line = lines_after[0]
line_pieces = line.split()
if len(line_pieces) != 6:
break
# Check against this pattern in the final position
# "%02d:%02d:%02d.%03d"
date_pieces = line_pieces[5].split(":")
if len(date_pieces) != 3:
break
lines_after.pop(0)
real_details.append({
'id': line_pieces[0],
'tag': line_pieces[1],
'vm_size': line_pieces[2],
'date': line_pieces[3],
'vm_clock': line_pieces[4] + " " + line_pieces[5],
})
return real_details
def _parse(self, cmd_output):
# Analysis done of qemu-img.c to figure out what is going on here
# Find all points start with some chars and then a ':' then a newline
# and then handle the results of those 'top level' items in a separate
# function.
#
# TODO(harlowja): newer versions might have a json output format
# we should switch to that whenever possible.
# see: http://bit.ly/XLJXDX
contents = {}
lines = [x for x in cmd_output.splitlines() if x.strip()]
while lines:
line = lines.pop(0)
top_level = self.TOP_LEVEL_RE.match(line)
if top_level:
root = self._canonicalize(top_level.group(1))
if not root:
continue
root_details = top_level.group(2).strip()
details = self._extract_details(root, root_details, lines)
contents[root] = details
return contents