nova/nova/block_device.py

75 lines
2.1 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 Isaku Yamahata <yamahata@valinux co jp>
# 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.
import re
DEFAULT_ROOT_DEV_NAME = '/dev/sda1'
def properties_root_device_name(properties):
"""get root device name from image meta data.
If it isn't specified, return None.
"""
root_device_name = None
# NOTE(yamahata): see image_service.s3.s3create()
for bdm in properties.get('mappings', []):
if bdm['virtual'] == 'root':
root_device_name = bdm['device']
# NOTE(yamahata): register_image's command line can override
# <machine>.manifest.xml
if 'root_device_name' in properties:
root_device_name = properties['root_device_name']
return root_device_name
_ephemeral = re.compile('^ephemeral(\d|[1-9]\d+)$')
def is_ephemeral(device_name):
return _ephemeral.match(device_name)
def ephemeral_num(ephemeral_name):
assert is_ephemeral(ephemeral_name)
return int(_ephemeral.sub('\\1', ephemeral_name))
def is_swap_or_ephemeral(device_name):
return device_name == 'swap' or is_ephemeral(device_name)
def mappings_prepend_dev(mappings):
"""Prepend '/dev/' to 'device' entry of swap/ephemeral virtual type"""
for m in mappings:
virtual = m['virtual']
if (is_swap_or_ephemeral(virtual) and
(not m['device'].startswith('/'))):
m['device'] = '/dev/' + m['device']
return mappings
_dev = re.compile('^/dev/')
def strip_dev(device_name):
"""remove leading '/dev/'"""
return _dev.sub('', device_name)