gantt/nova/block_device.py
Mark McLoughlin 7e9566cf08 Use CONF.import_opt() for nova.config opts
The only reason for importing nova.config now is where one of the
options defined in that file is needed. Rather than importing
nova.config using an import statement, use CONF.import_opt() so
that it is clear which option we actually require.

In future, we will move many options out of nova.config so many
of these import_opt() calls will either go away or cause a module
other than nova.config to be imported.

Change-Id: I0646efddecdf2530903afd50c1f4364cb1d5dce1
2012-11-20 00:04:49 +00:00

150 lines
4.4 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
from nova.openstack.common import cfg
CONF = cfg.CONF
CONF.import_opt('compute_driver', 'nova.config')
DEFAULT_ROOT_DEV_NAME = '/dev/sda1'
_DEFAULT_MAPPINGS = {'ami': 'sda1',
'ephemeral0': 'sda2',
'root': DEFAULT_ROOT_DEV_NAME,
'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 CONF.compute_driver.endswith('xenapi.XenAPIDriver'):
root_device_name = '/dev/xvda'
else:
return _DEFAULT_MAPPINGS
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']:
continue
# ebs volume case
if (bdm['volume_id'] or bdm['snapshot_id']):
ebs_devices.append(bdm['device_name'])
continue
virtual_name = bdm['virtual_name']
if not virtual_name:
continue
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
ebs_devices.sort()
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()