# Copyright (c) 2012 NetApp, 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. import errno import os import time from os_brick.remotefs import remotefs as remotefs_brick from oslo_concurrency import processutils as putils from oslo_config import cfg from oslo_log import log as logging from oslo_utils import units import six from cinder import exception from cinder.i18n import _, _LE, _LI, _LW from cinder.image import image_utils from cinder import utils from cinder.volume import driver from cinder.volume.drivers import remotefs VERSION = '1.3.0' LOG = logging.getLogger(__name__) nfs_opts = [ cfg.StrOpt('nfs_shares_config', default='/etc/cinder/nfs_shares', help='File with the list of available nfs shares'), cfg.BoolOpt('nfs_sparsed_volumes', default=True, help=('Create volumes as sparsed files which take no space.' 'If set to False volume is created as regular file.' 'In such case volume creation takes a lot of time.')), cfg.FloatOpt('nfs_used_ratio', default=0.95, help=('Percent of ACTUAL usage of the underlying volume ' 'before no new volumes can be allocated to the volume ' 'destination.')), cfg.FloatOpt('nfs_oversub_ratio', default=1.0, help=('This will compare the allocated to available space on ' 'the volume destination. If the ratio exceeds this ' 'number, the destination will no longer be valid.')), cfg.StrOpt('nfs_mount_point_base', default='$state_path/mnt', help=('Base dir containing mount points for nfs shares.')), cfg.StrOpt('nfs_mount_options', default=None, help=('Mount options passed to the nfs client. See section ' 'of the nfs man page for details.')), cfg.IntOpt('nfs_mount_attempts', default=3, help=('The number of attempts to mount nfs shares before ' 'raising an error. At least one attempt will be ' 'made to mount an nfs share, regardless of the ' 'value specified.')), ] CONF = cfg.CONF CONF.register_opts(nfs_opts) class NfsDriver(driver.ExtendVD, remotefs.RemoteFSDriver): """NFS based cinder driver. Creates file on NFS share for using it as block device on hypervisor. """ driver_volume_type = 'nfs' driver_prefix = 'nfs' volume_backend_name = 'Generic_NFS' VERSION = VERSION def __init__(self, execute=putils.execute, *args, **kwargs): self._remotefsclient = None super(NfsDriver, self).__init__(*args, **kwargs) self.configuration.append_config_values(nfs_opts) root_helper = utils.get_root_helper() # base bound to instance is used in RemoteFsConnector. self.base = getattr(self.configuration, 'nfs_mount_point_base', CONF.nfs_mount_point_base) self.base = os.path.realpath(self.base) opts = getattr(self.configuration, 'nfs_mount_options', CONF.nfs_mount_options) nas_mount_options = getattr(self.configuration, 'nas_mount_options', None) if nas_mount_options is not None: LOG.debug('overriding nfs_mount_options with nas_mount_options') opts = nas_mount_options self._remotefsclient = remotefs_brick.RemoteFsClient( 'nfs', root_helper, execute=execute, nfs_mount_point_base=self.base, nfs_mount_options=opts) self._sparse_copy_volume_data = True def set_execute(self, execute): super(NfsDriver, self).set_execute(execute) if self._remotefsclient: self._remotefsclient.set_execute(execute) def do_setup(self, context): """Any initialization the volume driver does while starting.""" super(NfsDriver, self).do_setup(context) config = self.configuration.nfs_shares_config if not config: msg = (_("There's no NFS config file configured (%s)") % 'nfs_shares_config') LOG.warning(msg) raise exception.NfsException(msg) if not os.path.exists(config): msg = (_("NFS config file at %(config)s doesn't exist") % {'config': config}) LOG.warning(msg) raise exception.NfsException(msg) if not self.configuration.nfs_oversub_ratio > 0: msg = _("NFS config 'nfs_oversub_ratio' invalid. Must be > 0: " "%s") % self.configuration.nfs_oversub_ratio LOG.error(msg) raise exception.InvalidConfigurationValue(msg) if not ((self.configuration.nfs_used_ratio > 0) and (self.configuration.nfs_used_ratio <= 1)): msg = _("NFS config 'nfs_used_ratio' invalid. Must be > 0 " "and <= 1.0: %s") % self.configuration.nfs_used_ratio LOG.error(msg) raise exception.InvalidConfigurationValue(msg) self.shares = {} # address : options # Check if mount.nfs is installed on this system; note that we don't # need to be root to see if the package is installed. package = 'mount.nfs' try: self._execute(package, check_exit_code=False, run_as_root=False) except OSError as exc: if exc.errno == errno.ENOENT: msg = _('%s is not installed') % package raise exception.NfsException(msg) else: raise # Now that all configuration data has been loaded (shares), # we can "set" our final NAS file security options. self.set_nas_security_options(self._is_voldb_empty_at_startup) def _ensure_share_mounted(self, nfs_share): mnt_flags = [] if self.shares.get(nfs_share) is not None: mnt_flags = self.shares[nfs_share].split() num_attempts = max(1, self.configuration.nfs_mount_attempts) for attempt in range(num_attempts): try: self._remotefsclient.mount(nfs_share, mnt_flags) return except Exception as e: if attempt == (num_attempts - 1): LOG.error(_LE('Mount failure for %(share)s after ' '%(count)d attempts.'), { 'share': nfs_share, 'count': num_attempts}) raise exception.NfsException(six.text_type(e)) LOG.debug('Mount attempt %(attempt)d failed: %(exc)s.\n' 'Retrying mount ...', {'attempt': attempt, 'exc': e}) time.sleep(1) def _find_share(self, volume_size_in_gib): """Choose NFS share among available ones for given volume size. For instances with more than one share that meets the criteria, the share with the least "allocated" space will be selected. :param volume_size_in_gib: int size in GB """ if not self._mounted_shares: raise exception.NfsNoSharesMounted() target_share = None target_share_reserved = 0 for nfs_share in self._mounted_shares: if not self._is_share_eligible(nfs_share, volume_size_in_gib): continue _total_size, _total_available, total_allocated = \ self._get_capacity_info(nfs_share) if target_share is not None: if target_share_reserved > total_allocated: target_share = nfs_share target_share_reserved = total_allocated else: target_share = nfs_share target_share_reserved = total_allocated if target_share is None: raise exception.NfsNoSuitableShareFound( volume_size=volume_size_in_gib) LOG.debug('Selected %s as target nfs share.', target_share) return target_share def _is_share_eligible(self, nfs_share, volume_size_in_gib): """Verifies NFS share is eligible to host volume with given size. First validation step: ratio of actual space (used_space / total_space) is less than 'nfs_used_ratio'. Second validation step: apparent space allocated (differs from actual space used when using sparse files) and compares the apparent available space (total_available * nfs_oversub_ratio) to ensure enough space is available for the new volume. :param nfs_share: nfs share :param volume_size_in_gib: int size in GB """ used_ratio = self.configuration.nfs_used_ratio oversub_ratio = self.configuration.nfs_oversub_ratio requested_volume_size = volume_size_in_gib * units.Gi total_size, total_available, total_allocated = \ self._get_capacity_info(nfs_share) apparent_size = max(0, total_size * oversub_ratio) apparent_available = max(0, apparent_size - total_allocated) used = (total_size - total_available) / total_size if used > used_ratio: # NOTE(morganfainberg): We check the used_ratio first since # with oversubscription it is possible to not have the actual # available space but be within our oversubscription limit # therefore allowing this share to still be selected as a valid # target. LOG.debug('%s is above nfs_used_ratio', nfs_share) return False if apparent_available <= requested_volume_size: LOG.debug('%s is above nfs_oversub_ratio', nfs_share) return False if total_allocated / total_size >= oversub_ratio: LOG.debug('%s reserved space is above nfs_oversub_ratio', nfs_share) return False return True def _get_mount_point_for_share(self, nfs_share): """Needed by parent class.""" return self._remotefsclient.get_mount_point(nfs_share) def _get_capacity_info(self, nfs_share): """Calculate available space on the NFS share. :param nfs_share: example 172.18.194.100:/var/nfs """ run_as_root = self._execute_as_root mount_point = self._get_mount_point_for_share(nfs_share) df, _ = self._execute('stat', '-f', '-c', '%S %b %a', mount_point, run_as_root=run_as_root) block_size, blocks_total, blocks_avail = map(float, df.split()) total_available = block_size * blocks_avail total_size = block_size * blocks_total du, _ = self._execute('du', '-sb', '--apparent-size', '--exclude', '*snapshot*', mount_point, run_as_root=run_as_root) total_allocated = float(du.split()[0]) return total_size, total_available, total_allocated def _get_mount_point_base(self): return self.base def extend_volume(self, volume, new_size): """Extend an existing volume to the new size.""" LOG.info(_LI('Extending volume %s.'), volume['id']) extend_by = int(new_size) - volume['size'] if not self._is_share_eligible(volume['provider_location'], extend_by): raise exception.ExtendVolumeError(reason='Insufficient space to' ' extend volume %s to %sG' % (volume['id'], new_size)) path = self.local_path(volume) LOG.info(_LI('Resizing file to %sG...'), new_size) image_utils.resize_image(path, new_size, run_as_root=self._execute_as_root) if not self._is_file_size_equal(path, new_size): raise exception.ExtendVolumeError( reason='Resizing image file failed.') def _is_file_size_equal(self, path, size): """Checks if file size at path is equal to size.""" data = image_utils.qemu_img_info(path, run_as_root=self._execute_as_root) virt_size = data.virtual_size / units.Gi return virt_size == size def set_nas_security_options(self, is_new_cinder_install): """Determine the setting to use for Secure NAS options. Value of each NAS Security option is checked and updated. If the option is currently 'auto', then it is set to either true or false based upon if this is a new Cinder installation. The RemoteFS variable '_execute_as_root' will be updated for this driver. :param is_new_cinder_install: bool indication of new Cinder install """ doc_html = "http://docs.openstack.org/admin-guide-cloud/content" \ "/nfs_backend.html" self._ensure_shares_mounted() if not self._mounted_shares: raise exception.NfsNoSharesMounted() nfs_mount = self._get_mount_point_for_share(self._mounted_shares[0]) self.configuration.nas_secure_file_permissions = \ self._determine_nas_security_option_setting( self.configuration.nas_secure_file_permissions, nfs_mount, is_new_cinder_install) LOG.debug('NAS variable secure_file_permissions setting is: %s', self.configuration.nas_secure_file_permissions) if self.configuration.nas_secure_file_permissions == 'false': LOG.warning(_LW("The NAS file permissions mode will be 666 " "(allowing other/world read & write access). " "This is considered an insecure NAS environment. " "Please see %s for information on a secure " "NFS configuration."), doc_html) self.configuration.nas_secure_file_operations = \ self._determine_nas_security_option_setting( self.configuration.nas_secure_file_operations, nfs_mount, is_new_cinder_install) # If secure NAS, update the '_execute_as_root' flag to not # run as the root user; run as process' user ID. if self.configuration.nas_secure_file_operations == 'true': self._execute_as_root = False LOG.debug('NAS variable secure_file_operations setting is: %s', self.configuration.nas_secure_file_operations) if self.configuration.nas_secure_file_operations == 'false': LOG.warning(_LW("The NAS file operations will be run as " "root: allowing root level access at the storage " "backend. This is considered an insecure NAS " "environment. Please see %s " "for information on a secure NAS configuration."), doc_html)