nova/nova/virt/powervm/blockdev.py

426 lines
16 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2012 IBM
#
# 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 hashlib
import os
import re
from eventlet import greenthread
from nova import utils
from nova.image import glance
from nova.openstack.common import cfg
from nova.openstack.common import excutils
from nova.openstack.common import log as logging
from nova.virt import images
from nova.virt.powervm import command
from nova.virt.powervm import common
from nova.virt.powervm import constants
from nova.virt.powervm import exception
LOG = logging.getLogger(__name__)
CONF = cfg.CONF
class PowerVMDiskAdapter(object):
pass
class PowerVMLocalVolumeAdapter(PowerVMDiskAdapter):
"""Default block device providor for PowerVM
This disk adapter uses logical volumes on the hosting VIOS
to provide backing block devices for instances/LPARs
"""
def __init__(self, connection):
super(PowerVMLocalVolumeAdapter, self).__init__()
self.command = command.IVMCommand()
self._connection = None
self.connection_data = connection
def _set_connection(self):
if self._connection is None:
self._connection = common.ssh_connect(self.connection_data)
def create_volume(self, size):
"""Creates a logical volume with a minimum size
:param size: size of the logical volume in bytes
:returns: string -- the name of the new logical volume.
:raises: PowerVMNoSpaceLeftOnVolumeGroup
"""
return self._create_logical_volume(size)
def delete_volume(self, disk_name):
"""Removes the Logical Volume and its associated vSCSI connection
:param disk_name: name of Logical Volume device in /dev/
"""
LOG.debug(_("Removing the logical volume '%s'") % disk_name)
self._remove_logical_volume(disk_name)
def create_volume_from_image(self, context, instance, image_id):
"""Creates a Logical Volume and copies the specified image to it
:param context: nova context used to retrieve image from glance
:param instance: instance to create the volume for
:param image_id: image_id reference used to locate image in glance
:returns: dictionary with the name of the created
Logical Volume device in 'device_name' key
"""
file_name = '.'.join([image_id, 'gz'])
file_path = os.path.join(CONF.powervm_img_local_path,
file_name)
if not os.path.isfile(file_path):
LOG.debug(_("Fetching image '%s' from glance") % image_id)
images.fetch_to_raw(context, image_id, file_path,
instance['user_id'],
project_id=instance['project_id'])
else:
LOG.debug((_("Using image found at '%s'") % file_path))
LOG.debug(_("Ensuring image '%s' exists on IVM") % file_path)
remote_path = CONF.powervm_img_remote_path
remote_file_name, size = self._copy_image_file(file_path, remote_path)
# calculate root device size in bytes
# we respect the minimum root device size in constants
size_gb = max(instance['instance_type']['root_gb'],
constants.POWERVM_MIN_ROOT_GB)
size = size_gb * 1024 * 1024 * 1024
try:
LOG.debug(_("Creating logical volume of size %s bytes") % size)
disk_name = self._create_logical_volume(size)
LOG.debug(_("Copying image to the device '%s'") % disk_name)
self._copy_file_to_device(remote_file_name, disk_name)
except Exception:
LOG.error(_("Error while creating logical volume from image. "
"Will attempt cleanup."))
# attempt cleanup of logical volume before re-raising exception
with excutils.save_and_reraise_exception():
try:
self.delete_volume(disk_name)
except Exception:
msg = _('Error while attempting cleanup of failed '
'deploy to logical volume.')
LOG.exception(msg)
return {'device_name': disk_name}
def create_image_from_volume(self, device_name, context,
image_id, image_meta):
"""Capture the contents of a volume and upload to glance
:param device_name: device in /dev/ to capture
:param context: nova context for operation
:param image_id: image reference to pre-created image in glance
:param image_meta: metadata for new image
"""
# do the disk copy
dest_file_path = common.aix_path_join(CONF.powervm_img_remote_path,
image_id)
self._copy_device_to_file(device_name, dest_file_path)
# compress and copy the file back to the nova-compute host
snapshot_file_path = self._copy_image_file_from_host(
dest_file_path, CONF.powervm_img_local_path,
compress=True)
# get glance service
glance_service, image_id = glance.get_remote_image_service(
context, image_id)
# upload snapshot file to glance
with open(snapshot_file_path, 'r') as img_file:
glance_service.update(context,
image_id,
image_meta,
img_file)
LOG.debug(_("Snapshot added to glance."))
# clean up local image file
try:
os.remove(snapshot_file_path)
except OSError as ose:
LOG.warn(_("Failed to clean up snapshot file "
"%(snapshot_file_path)s") % locals())
def migrate_volume(self):
raise NotImplementedError()
def attach_volume_to_host(self, *args, **kargs):
pass
def detach_volume_from_host(self, *args, **kargs):
pass
def _create_logical_volume(self, size):
"""Creates a logical volume with a minimum size.
:param size: size of the logical volume in bytes
:returns: string -- the name of the new logical volume.
:raises: PowerVMNoSpaceLeftOnVolumeGroup
"""
vgs = self.run_vios_command(self.command.lsvg())
cmd = self.command.lsvg('%s -field vgname freepps -fmt :' %
' '.join(vgs))
output = self.run_vios_command(cmd)
found_vg = None
# If it's not a multiple of 1MB we get the next
# multiple and use it as the megabyte_size.
megabyte = 1024 * 1024
if (size % megabyte) != 0:
megabyte_size = int(size / megabyte) + 1
else:
megabyte_size = size / megabyte
# Search for a volume group with enough free space for
# the new logical volume.
for vg in output:
# Returned output example: 'rootvg:396 (25344 megabytes)'
match = re.search(r'^(\w+):\d+\s\((\d+).+$', vg)
if match is None:
continue
vg_name, avail_size = match.groups()
if megabyte_size <= int(avail_size):
found_vg = vg_name
break
if not found_vg:
LOG.error(_('Could not create logical volume. '
'No space left on any volume group.'))
raise exception.PowerVMNoSpaceLeftOnVolumeGroup()
cmd = self.command.mklv('%s %sB' % (found_vg, size / 512))
lv_name = self.run_vios_command(cmd)[0]
return lv_name
def _remove_logical_volume(self, lv_name):
"""Removes the lv and the connection between its associated vscsi.
:param lv_name: a logical volume name
"""
cmd = self.command.rmvdev('-vdev %s -rmlv' % lv_name)
self.run_vios_command(cmd)
def _copy_file_to_device(self, source_path, device, decompress=True):
"""Copy file to device.
:param source_path: path to input source file
:param device: output device name
:param decompress: if True (default) the file will be decompressed
on the fly while being copied to the drive
"""
if decompress:
cmd = ('gunzip -c %s | dd of=/dev/%s bs=1024k' %
(source_path, device))
else:
cmd = 'dd if=%s of=/dev/%s bs=1024k' % (source_path, device)
self.run_vios_command_as_root(cmd)
def _copy_device_to_file(self, device_name, file_path):
"""Copy a device to a file using dd
:param device_name: device name to copy from
:param file_path: output file path
"""
cmd = 'dd if=/dev/%s of=%s bs=1024k' % (device_name, file_path)
self.run_vios_command_as_root(cmd)
def _md5sum_remote_file(self, remote_path):
# AIX6/VIOS cannot md5sum files with sizes greater than ~2GB
cmd = ("perl -MDigest::MD5 -e 'my $file = \"%s\"; open(FILE, $file); "
"binmode(FILE); "
"print Digest::MD5->new->addfile(*FILE)->hexdigest, "
"\" $file\n\";'" % remote_path)
output = self.run_vios_command_as_root(cmd)
return output[0]
def _copy_image_file(self, source_path, remote_path, decompress=False):
"""Copy file to VIOS, decompress it, and return its new size and name.
:param source_path: source file path
:param remote_path remote file path
:param decompress: if True, decompressess the file after copying;
if False (default), just copies the file
"""
# Calculate source image checksum
hasher = hashlib.md5()
block_size = 0x10000
img_file = file(source_path, 'r')
buf = img_file.read(block_size)
while len(buf) > 0:
hasher.update(buf)
buf = img_file.read(block_size)
source_cksum = hasher.hexdigest()
comp_path = os.path.join(remote_path, os.path.basename(source_path))
uncomp_path = comp_path.rstrip(".gz")
if not decompress:
final_path = comp_path
else:
final_path = uncomp_path
# Check whether the image is already on IVM
output = self.run_vios_command("ls %s" % final_path,
check_exit_code=False)
# If the image does not exist already
if not output:
# Copy file to IVM
common.ftp_put_command(self.connection_data, source_path,
remote_path)
# Verify image file checksums match
output = self._md5sum_remote_file(final_path)
if not output:
LOG.error(_("Unable to get checksum"))
raise exception.PowerVMFileTransferFailed()
if source_cksum != output.split(' ')[0]:
LOG.error(_("Image checksums do not match"))
raise exception.PowerVMFileTransferFailed()
if decompress:
# Unzip the image
cmd = "/usr/bin/gunzip %s" % comp_path
output = self.run_vios_command_as_root(cmd)
# Remove existing image file
cmd = "/usr/bin/rm -f %s.*" % uncomp_path
output = self.run_vios_command_as_root(cmd)
# Rename unzipped image
cmd = "/usr/bin/mv %s %s" % (uncomp_path, final_path)
output = self.run_vios_command_as_root(cmd)
# Remove compressed image file
cmd = "/usr/bin/rm -f %s" % comp_path
output = self.run_vios_command_as_root(cmd)
else:
LOG.debug(_("Image found on host at '%s'") % final_path)
# Calculate file size in multiples of 512 bytes
output = self.run_vios_command("ls -o %s|awk '{print $4}'" %
final_path, check_exit_code=False)
if output:
size = int(output[0])
else:
LOG.error(_("Uncompressed image file not found"))
raise exception.PowerVMFileTransferFailed()
if (size % 512 != 0):
size = (int(size / 512) + 1) * 512
return final_path, size
def _copy_image_file_from_host(self, remote_source_path, local_dest_dir,
compress=False):
"""
Copy a file from IVM to the nova-compute host,
and return the location of the copy
:param remote_source_path remote source file path
:param local_dest_dir local destination directory
:param compress: if True, compress the file before transfer;
if False (default), copy the file as is
"""
temp_str = common.aix_path_join(local_dest_dir,
os.path.basename(remote_source_path))
local_file_path = temp_str + '.gz'
if compress:
copy_from_path = remote_source_path + '.gz'
else:
copy_from_path = remote_source_path
if compress:
# Gzip the file
cmd = "/usr/bin/gzip %s" % remote_source_path
self.run_vios_command_as_root(cmd)
# Cleanup uncompressed remote file
cmd = "/usr/bin/rm -f %s" % remote_source_path
self.run_vios_command_as_root(cmd)
# Get file checksum
output = self._md5sum_remote_file(copy_from_path)
if not output:
LOG.error(_("Unable to get checksum"))
msg_args = {'file_path': copy_from_path}
raise exception.PowerVMFileTransferFailed(**msg_args)
else:
source_chksum = output.split(' ')[0]
# Copy file to host
common.ftp_get_command(self.connection_data,
copy_from_path,
local_file_path)
# Calculate copied image checksum
with open(local_file_path, 'r') as image_file:
hasher = hashlib.md5()
block_size = 0x10000
buf = image_file.read(block_size)
while len(buf) > 0:
hasher.update(buf)
buf = image_file.read(block_size)
dest_chksum = hasher.hexdigest()
# do comparison
if source_chksum and dest_chksum != source_chksum:
LOG.error(_("Image checksums do not match"))
raise exception.PowerVMFileTransferFailed()
# Cleanup transferred remote file
cmd = "/usr/bin/rm -f %s" % copy_from_path
output = self.run_vios_command_as_root(cmd)
return local_file_path
def run_vios_command(self, cmd, check_exit_code=True):
"""Run a remote command using an active ssh connection.
:param command: String with the command to run.
"""
self._set_connection()
stdout, stderr = utils.ssh_execute(self._connection, cmd,
check_exit_code=check_exit_code)
return stdout.strip().splitlines()
def run_vios_command_as_root(self, command, check_exit_code=True):
"""Run a remote command as root using an active ssh connection.
:param command: List of commands.
"""
self._set_connection()
stdout, stderr = common.ssh_command_as_root(
self._connection, command, check_exit_code=check_exit_code)
return stdout.read().splitlines()