def CreateFile(cls, path, size, create_folders=False,
_file_path_acceptance_fn=None):
"""Create a new file and its file device helper.
@param size: the size in MiBs the file should be truncated to.
@param create_folders: create the directories for the path if necessary
(using L{ganeti.utils.io.Makedirs})
@rtype: FileDeviceHelper
@return: The FileDeviceHelper object representing the object.
@raise errors.FileStoragePathError: if the file path is disallowed by policy
"""
if not _file_path_acceptance_fn:
_file_path_acceptance_fn = CheckFileStoragePathAcceptance
_file_path_acceptance_fn(path)
if create_folders:
folder = os.path.dirname(path)
io.Makedirs(folder)
try:
fd = os.open(path, os.O_RDWR | os.O_CREAT | os.O_EXCL)
f = os.fdopen(fd, "w")
f.truncate(size * 1024 * 1024)
f.close()
except EnvironmentError as err:
base.ThrowError("%s: can't create: %s", path, str(err))
return FileDeviceHelper(path,
_file_path_acceptance_fn=_file_path_acceptance_fn)
def Mount(self):
"""Try and mount the volume. No-op if the volume is already mounted.
@raises BlockDeviceError: if the mount was unsuccessful
@rtype: context manager
@return: A simple context manager that lets you use this volume for
short lived operations like so::
with volume.mount():
# Do operations on volume
# Volume is now unmounted
"""
class _GlusterVolumeContextManager(object):
def __init__(self, volume):
self.volume = volume
def __enter__(self):
# We're already mounted.
return self
def __exit__(self, *exception_information):
self.volume.Unmount()
return False # do not swallow exceptions.
if self._IsMounted():
return _GlusterVolumeContextManager(self)
command = [
"mount", "-t", "glusterfs",
self._GetFUSEMountString(), self.mount_point
]
io.Makedirs(self.mount_point)
self._run_cmd(
" ".join(command),
# Why set cwd? Because it's an area we control. If,
# for some unfortunate reason, this folder exists:
# "/%s/" % _GetFUSEMountString()
# ...then the gluster parser gets confused and treats
# _GetFUSEMountString() as your mount point and
# self.mount_point becomes a syntax error.
cwd=self.mount_point)
# mount.glusterfs exits with code 0 even after failure.
# https://bugzilla.redhat.com/show_bug.cgi?id=1031973
if not self._IsMounted():
reasons = self._GuessMountFailReasons()
if not reasons:
reasons = "%r failed." % (" ".join(command))
base.ThrowError("%r: mount failure: %s", self.mount_point, reasons)
return _GlusterVolumeContextManager(self)