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https://github.com/kevingruesser/bootstrap-vz.git
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a840dc28f3
automatically from the first available partition. There is no need to fiddle with sizes while keeping the offsets in mind any longer. Introduced Bytes() class which makes it a lot easier to handle size units.
78 lines
3.1 KiB
Python
78 lines
3.1 KiB
Python
from common.fs.loopbackvolume import LoopbackVolume
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from base.fs.exceptions import VolumeError
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from common.tools import log_check_call
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from common.fs import get_partitions
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class QEMUVolume(LoopbackVolume):
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def _before_create(self, e):
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self.image_path = e.image_path
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vol_size = str(self.size.get_qty_in('MiB')) + 'M'
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log_check_call(['/usr/bin/qemu-img', 'create', '-f', self.qemu_format, self.image_path, vol_size])
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def _check_nbd_module(self):
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from base.fs.partitionmaps.none import NoPartitions
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if isinstance(self.partition_map, NoPartitions):
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if not self._module_loaded('nbd'):
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msg = ('The kernel module `nbd\' must be loaded '
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'(`modprobe nbd\') to attach .{extension} images'
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.format(extension=self.extension))
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raise VolumeError(msg)
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else:
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num_partitions = len(self.partition_map.partitions)
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if not self._module_loaded('nbd'):
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msg = ('The kernel module `nbd\' must be loaded '
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'(`modprobe nbd max_part={num_partitions}\') to attach .{extension} images'
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.format(num_partitions=num_partitions, extension=self.extension))
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raise VolumeError(msg)
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nbd_max_part = int(self._module_param('nbd', 'max_part'))
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if nbd_max_part < num_partitions:
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# Found here: http://bethesignal.org/blog/2011/01/05/how-to-mount-virtualbox-vdi-image/
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msg = ('The kernel module `nbd\' was loaded with the max_part '
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'parameter set to {max_part}, which is below '
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'the amount of partitions for this volume ({num_partitions}). '
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'Reload the nbd kernel module with max_part set to at least {num_partitions} '
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'(`rmmod nbd; modprobe nbd max_part={num_partitions}\').'
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.format(max_part=nbd_max_part, num_partitions=num_partitions))
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raise VolumeError(msg)
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def _before_attach(self, e):
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self._check_nbd_module()
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self.loop_device_path = self._find_free_nbd_device()
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log_check_call(['/usr/bin/qemu-nbd', '--connect', self.loop_device_path, self.image_path])
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self.device_path = self.loop_device_path
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def _before_detach(self, e):
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log_check_call(['/usr/bin/qemu-nbd', '--disconnect', self.loop_device_path])
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del self.loop_device_path
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del self.device_path
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def _module_loaded(self, module):
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import re
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regexp = re.compile('^{module} +'.format(module=module))
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with open('/proc/modules') as loaded_modules:
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for line in loaded_modules:
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match = regexp.match(line)
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if match is not None:
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return True
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return False
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def _module_param(self, module, param):
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import os.path
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param_path = os.path.join('/sys/module', module, 'parameters', param)
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with open(param_path) as param:
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return param.read().strip()
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# From http://lists.gnu.org/archive/html/qemu-devel/2011-11/msg02201.html
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# Apparently it's not in the current qemu-nbd shipped with wheezy
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def _is_nbd_used(self, device_name):
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return device_name in get_partitions()
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def _find_free_nbd_device(self):
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import os.path
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for i in xrange(0, 15):
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device_name = 'nbd' + str(i)
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if not self._is_nbd_used(device_name):
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return os.path.join('/dev', device_name)
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raise VolumeError('Unable to find free nbd device.')
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