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# Copyright 2016 Andreas Florath (andreas@florath.net)
#
# 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 logging
import os
from diskimage_builder.block_device.exception import \
BlockDeviceSetupException
from diskimage_builder.block_device.plugin import NodeBase
from diskimage_builder.block_device.plugin import PluginBase
from diskimage_builder.block_device.utils import exec_sudo
from diskimage_builder.block_device.utils import parse_abs_size_spec
logger = logging.getLogger(__name__)
def image_create(filename, size):
logger.info("Create image file [%s]", filename)
with open(filename, "w") as fd:
fd.seek(size - 1)
fd.write("\0")
def image_delete(filename):
logger.info("Remove image file [%s]", filename)
os.remove(filename)
def loopdev_attach(filename, block_size):
if str(block_size) not in ['512', '4096']:
logger.warning("Block device size is set to %s, only 512 and "
"4096 has been tested.", block_size)
logger.info("loopdev attach")
log_msg = ("Calling [sudo losetup --sector-size %s --show -f %s]"
% (str(block_size), filename))
logger.debug(log_msg)
block_device = exec_sudo(["losetup", "--sector-size", str(block_size),
"--show", "-f", filename])
# [:-1]: Cut of the newline
block_device = block_device[:-1]
logger.info("New block device [%s]", block_device)
return block_device
def loopdev_detach(loopdev):
logger.info("loopdev detach")
# loopback dev may be tied up a bit by udev events triggered
# by partition events
for try_cnt in range(10, 1, -1):
try:
exec_sudo(["losetup", "-d", loopdev])
return
except BlockDeviceSetupException as e:
# Do not raise an error - maybe other cleanup methods
# can at least do some more work.
logger.error("loopdev detach failed (%s)", e.returncode)
logger.debug("Gave up trying to detach [%s]", loopdev)
return 1
class LocalLoopNode(NodeBase):
"""Level0: Local loop image device handling.
This class handles local loop devices that can be used
for VM image installation.
"""
def __init__(self, config, default_config, state):
logger.debug("Creating LocalLoop object; config [%s] "
"default_config [%s]", config, default_config)
super(LocalLoopNode, self).__init__(config['name'], state)
if 'size' in config:
self.size = parse_abs_size_spec(config['size'])
logger.debug("Image size [%s]", self.size)
else:
self.size = parse_abs_size_spec(default_config['image-size'])
logger.debug("Using default image size [%s]", self.size)
if 'directory' in config:
self.image_dir = config['directory']
else:
self.image_dir = default_config['image-dir']
if 'DIB_BLOCK_SIZE' in os.environ:
self.block_size = os.environ['DIB_BLOCK_SIZE']
elif 'block_size' in config:
self.block_size = config['block_size']
else:
self.block_size = 512
self.filename = os.path.join(self.image_dir, self.name + ".raw")
def get_edges(self):
"""Because this is created without base, there are no edges."""
return ([], [])
def create(self):
logger.debug("[%s] Creating loop on [%s] with size [%d]",
self.name, self.filename, self.size)
self.add_rollback(image_delete, self.filename)
image_create(self.filename, self.size)
block_device = loopdev_attach(self.filename, self.block_size)
self.add_rollback(loopdev_detach, block_device)
if 'blockdev' not in self.state:
self.state['blockdev'] = {}
self.state['blockdev'][self.name] = {"device": block_device,
"image": self.filename}
logger.debug("Created loop name [%s] device [%s] image [%s]",
self.name, block_device, self.filename)
return
def umount(self):
loopdev_detach(self.state['blockdev'][self.name]['device'])
def delete(self):
image_delete(self.state['blockdev'][self.name]['image'])
class LocalLoop(PluginBase):
def __init__(self, config, defaults, state):
super(LocalLoop, self).__init__()
self.node = LocalLoopNode(config, defaults, state)
def get_nodes(self):
return [self.node]
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