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# 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
# 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
from nova import flags
_DEFAULT_MAPPINGS = {'ami': 'sda1',
'ephemeral0': 'sda2',
'swap': 'sda3'}
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) if device_name else device_name
_pref = re.compile('^((x?v|s)d)')
def strip_prefix(device_name):
""" remove both leading /dev/ and xvd or sd or vd """
device_name = strip_dev(device_name)
return _pref.sub('', device_name)
def instance_block_mapping(instance, bdms):
root_device_name = instance['root_device_name']
# NOTE(clayg): remove this when xenapi is setting default_root_device
if root_device_name is None:
if FLAGS.compute_driver.endswith('xenapi.XenAPIDriver'):
root_device_name = '/dev/xvda'
mappings = {}
mappings['ami'] = strip_dev(root_device_name)
mappings['root'] = root_device_name
default_ephemeral_device = instance.get('default_ephemeral_device')
if default_ephemeral_device:
mappings['ephemeral0'] = default_ephemeral_device
default_swap_device = instance.get('default_swap_device')
if default_swap_device:
mappings['swap'] = default_swap_device
ebs_devices = []
# 'ephemeralN', 'swap' and ebs
for bdm in bdms:
if bdm['no_device']:
# ebs volume case
if (bdm['volume_id'] or bdm['snapshot_id']):
virtual_name = bdm['virtual_name']
if not virtual_name:
if is_swap_or_ephemeral(virtual_name):
mappings[virtual_name] = bdm['device_name']
# NOTE(yamahata): I'm not sure how ebs device should be numbered.
# Right now sort by device name for deterministic
# result.
if ebs_devices:
nebs = 0
for ebs in ebs_devices:
mappings['ebs%d' % nebs] = ebs
nebs += 1
return mappings
def match_device(device):
"""Matches device name and returns prefix, suffix"""
match = re.match("(^/dev/x{0,1}[a-z]{0,1}d{0,1})([a-z]+)[0-9]*$", device)
if not match:
return None
return match.groups()
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