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OpenStack Study: configdrive.py**** CubicPower OpenStack Study ****
# Copyright 2012 Michael Still and Canonical Inc # 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. """Config Drive v2 helper.""" import os import shutil import tempfile from oslo.config import cfg from nova import exception from nova.openstack.common import fileutils from nova.openstack.common.gettextutils import _ from nova.openstack.common import log as logging from nova.openstack.common import units from nova import utils from nova import version LOG = logging.getLogger(__name__) configdrive_opts = [ cfg.StrOpt('config_drive_format', default='iso9660', help='Config drive format. One of iso9660 (default) or vfat'), cfg.StrOpt('config_drive_tempdir', default=tempfile.tempdir, help=('Where to put temporary files associated with ' 'config drive creation')), # force_config_drive is a string option, to allow for future behaviors # (e.g. use config_drive based on image properties) cfg.StrOpt('force_config_drive', help='Set to force injection to take place on a config drive ' '(if set, valid options are: always)'), cfg.StrOpt('mkisofs_cmd', default='genisoimage', help='Name and optionally path of the tool used for ' 'ISO image creation') ] CONF = cfg.CONF CONF.register_opts(configdrive_opts) # Config drives are 64mb, if we can't size to the exact size of the data CONFIGDRIVESIZE_BYTES = 64 * units.Mi
**** CubicPower OpenStack Study **** class ConfigDriveBuilder(object): """Build config drives, optionally as a context manager."""
**** CubicPower OpenStack Study **** def __init__(self, instance_md=None): self.imagefile = None # TODO(mikal): I don't think I can use utils.tempdir here, because # I need to have the directory last longer than the scope of this # method call self.tempdir = tempfile.mkdtemp(dir=CONF.config_drive_tempdir, prefix='cd_gen_') if instance_md is not None: self.add_instance_metadata(instance_md)
**** CubicPower OpenStack Study **** def __enter__(self): return self
**** CubicPower OpenStack Study **** def __exit__(self, exctype, excval, exctb): if exctype is not None: # NOTE(mikal): this means we're being cleaned up because an # exception was thrown. All bets are off now, and we should not # swallow the exception return False self.cleanup()
**** CubicPower OpenStack Study **** def _add_file(self, path, data): filepath = os.path.join(self.tempdir, path) dirname = os.path.dirname(filepath) fileutils.ensure_tree(dirname) with open(filepath, 'wb') as f: f.write(data)
**** CubicPower OpenStack Study **** def add_instance_metadata(self, instance_md): for (path, value) in instance_md.metadata_for_config_drive(): self._add_file(path, value) LOG.debug(_('Added %(filepath)s to config drive'), {'filepath': path})
**** CubicPower OpenStack Study **** def _make_iso9660(self, path): publisher = "%(product)s %(version)s" % { 'product': version.product_string(), 'version': version.version_string_with_package() } utils.execute(CONF.mkisofs_cmd, '-o', path, '-ldots', '-allow-lowercase', '-allow-multidot', '-l', '-publisher', publisher, '-quiet', '-J', '-r', '-V', 'config-2', self.tempdir, attempts=1, run_as_root=False)
**** CubicPower OpenStack Study **** def _make_vfat(self, path): # NOTE(mikal): This is a little horrible, but I couldn't find an # equivalent to genisoimage for vfat filesystems. with open(path, 'wb') as f: f.truncate(CONFIGDRIVESIZE_BYTES) utils.mkfs('vfat', path, label='config-2') mounted = False try: mountdir = tempfile.mkdtemp(dir=CONF.config_drive_tempdir, prefix='cd_mnt_') _out, err = utils.trycmd('mount', '-o', 'loop,uid=%d,gid=%d' % (os.getuid(), os.getgid()), path, mountdir, run_as_root=True) if err: raise exception.ConfigDriveMountFailed(operation='mount', error=err) mounted = True # NOTE(mikal): I can't just use shutils.copytree here, because the # destination directory already exists. This is annoying. for ent in os.listdir(self.tempdir): shutil.copytree(os.path.join(self.tempdir, ent), os.path.join(mountdir, ent)) finally: if mounted: utils.execute('umount', mountdir, run_as_root=True) shutil.rmtree(mountdir)
**** CubicPower OpenStack Study **** def make_drive(self, path): """Make the config drive. :param path: the path to place the config drive image at :raises ProcessExecuteError if a helper process has failed. """ if CONF.config_drive_format == 'iso9660': self._make_iso9660(path) elif CONF.config_drive_format == 'vfat': self._make_vfat(path) else: raise exception.ConfigDriveUnknownFormat( format=CONF.config_drive_format)
**** CubicPower OpenStack Study **** def cleanup(self): if self.imagefile: fileutils.delete_if_exists(self.imagefile) try: shutil.rmtree(self.tempdir) except OSError as e: LOG.error(_('Could not remove tmpdir: %s'), str(e)) def required_by(instance): return instance.get('config_drive') or CONF.force_config_drive
**** CubicPower OpenStack Study **** def required_by(instance): return instance.get('config_drive') or CONF.force_config_drive
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