salt/modules/bcache.py
# -*- coding: utf-8 -*-
'''
Module for managing BCache sets
BCache is a block-level caching mechanism similar to ZFS L2ARC/ZIL, dm-cache and fscache.
It works by formatting one block device as a cache set, then adding backend devices
(which need to be formatted as such) to the set and activating them.
It's available in Linux mainline kernel since 3.10
https://www.kernel.org/doc/Documentation/bcache.txt
This module needs the bcache userspace tools to function.
.. versionadded: 2016.3.0
'''
# Import python libs
from __future__ import absolute_import, print_function, unicode_literals
import logging
import os
import time
import re
from salt.ext import six
# Import salt libs
import salt.utils.path
log = logging.getLogger(__name__)
LOG = {
'trace': logging.TRACE,
'debug': logging.DEBUG,
'info': logging.INFO,
'warn': logging.WARNING,
'error': logging.ERROR,
'crit': logging.CRITICAL,
}
__func_alias__ = {
'attach_': 'attach',
'config_': 'config',
'super_': 'super',
}
HAS_BLKDISCARD = salt.utils.path.which('blkdiscard') is not None
def __virtual__():
'''
Only work when make-bcache is installed
'''
return salt.utils.path.which('make-bcache') is not None
def uuid(dev=None):
'''
Return the bcache UUID of a block device.
If no device is given, the Cache UUID is returned.
CLI example:
.. code-block:: bash
salt '*' bcache.uuid
salt '*' bcache.uuid /dev/sda
salt '*' bcache.uuid bcache0
'''
try:
if dev is None:
# take the only directory in /sys/fs/bcache and return it's basename
return list(salt.utils.path.os_walk('/sys/fs/bcache/'))[0][1][0]
else:
# basename of the /sys/block/{dev}/bcache/cache symlink target
return os.path.basename(_bcsys(dev, 'cache'))
except Exception:
return False
def attach_(dev=None):
'''
Attach a backing devices to a cache set
If no dev is given, all backing devices will be attached.
CLI example:
.. code-block:: bash
salt '*' bcache.attach sdc
salt '*' bcache.attach /dev/bcache1
:return: bool or None if nuttin' happened
'''
cache = uuid()
if not cache:
log.error('No cache to attach %s to', dev)
return False
if dev is None:
res = {}
for dev, data in status(alldevs=True).items():
if 'cache' in data:
res[dev] = attach_(dev)
return res if res else None
bcache = uuid(dev)
if bcache:
if bcache == cache:
log.info('%s is already attached to bcache %s, doing nothing', dev, cache)
return None
elif not detach(dev):
return False
log.debug('Attaching %s to bcache %s', dev, cache)
if not _bcsys(dev, 'attach', cache,
'error', 'Error attaching {0} to bcache {1}'.format(dev, cache)):
return False
return _wait(lambda: uuid(dev) == cache,
'error', '{0} received attach to bcache {1}, but did not comply'.format(dev, cache))
def detach(dev=None):
'''
Detach a backing device(s) from a cache set
If no dev is given, all backing devices will be attached.
Detaching a backing device will flush it's write cache.
This should leave the underlying device in a consistent state, but might take a while.
CLI example:
.. code-block:: bash
salt '*' bcache.detach sdc
salt '*' bcache.detach bcache1
'''
if dev is None:
res = {}
for dev, data in status(alldevs=True).items():
if 'cache' in data:
res[dev] = detach(dev)
return res if res else None
log.debug('Detaching %s', dev)
if not _bcsys(dev, 'detach', 'goaway', 'error', 'Error detaching {0}'.format(dev)):
return False
return _wait(lambda: uuid(dev) is False, 'error', '{0} received detach, but did not comply'.format(dev), 300)
def start():
'''
Trigger a start of the full bcache system through udev.
CLI example:
.. code-block:: bash
salt '*' bcache.start
'''
if not _run_all('udevadm trigger', 'error', 'Error starting bcache: %s'):
return False
elif not _wait(lambda: uuid() is not False, 'warn', 'Bcache system started, but no active cache set found.'):
return False
return True
def stop(dev=None):
'''
Stop a bcache device
If no device is given, all backing devices will be detached from the cache, which will subsequently be stopped.
.. warning::
'Stop' on an individual backing device means hard-stop;
no attempt at flushing will be done and the bcache device will seemingly 'disappear' from the device lists
CLI example:
.. code-block:: bash
salt '*' bcache.stop
'''
if dev is not None:
log.warning('Stopping %s, device will only reappear after reregistering!', dev)
if not _bcsys(dev, 'stop', 'goaway', 'error', 'Error stopping {0}'.format(dev)):
return False
return _wait(lambda: _sysfs_attr(_bcpath(dev)) is False, 'error', 'Device {0} did not stop'.format(dev), 300)
else:
cache = uuid()
if not cache:
log.warning('bcache already stopped?')
return None
if not _alltrue(detach()):
return False
elif not _fssys('stop', 'goaway', 'error', 'Error stopping cache'):
return False
return _wait(lambda: uuid() is False, 'error', 'Cache did not stop', 300)
def back_make(dev, cache_mode='writeback', force=False, attach=True, bucket_size=None):
'''
Create a backing device for attachment to a set.
Because the block size must be the same, a cache set already needs to exist.
CLI example:
.. code-block:: bash
salt '*' bcache.back_make sdc cache_mode=writeback attach=True
:param cache_mode: writethrough, writeback, writearound or none.
:param force: Overwrite existing bcaches
:param attach: Immediately attach the backing device to the set
:param bucket_size: Size of a bucket (see kernel doc)
'''
# pylint: disable=too-many-return-statements
cache = uuid()
if not cache:
log.error('No bcache set found')
return False
elif _sysfs_attr(_bcpath(dev)):
if not force:
log.error('%s already contains a bcache. Wipe it manually or use force', dev)
return False
elif uuid(dev) and not detach(dev):
return False
elif not stop(dev):
return False
dev = _devpath(dev)
block_size = _size_map(_fssys('block_size'))
# You might want to override, we pick the cache set's as sane default
if bucket_size is None:
bucket_size = _size_map(_fssys('bucket_size'))
cmd = 'make-bcache --block {0} --bucket {1} --{2} --bdev {3}'.format(block_size, bucket_size, cache_mode, dev)
if force:
cmd += ' --wipe-bcache'
if not _run_all(cmd, 'error', 'Error creating backing device {0}: %s'.format(dev)):
return False
elif not _sysfs_attr('fs/bcache/register', _devpath(dev),
'error', 'Error registering backing device {0}'.format(dev)):
return False
elif not _wait(lambda: _sysfs_attr(_bcpath(dev)) is not False,
'error', 'Backing device {0} did not register'.format(dev)):
return False
elif attach:
return attach_(dev)
return True
def cache_make(dev, reserved=None, force=False, block_size=None, bucket_size=None, attach=True):
'''
Create BCache cache on a block device.
If blkdiscard is available the entire device will be properly cleared in advance.
CLI example:
.. code-block:: bash
salt '*' bcache.cache_make sdb reserved=10% block_size=4096
:param reserved: if dev is a full device, create a partition table with this size empty.
.. note::
this increases the amount of reserved space available to SSD garbage collectors,
potentially (vastly) increasing performance
:param block_size: Block size of the cache; defaults to devices' logical block size
:param force: Overwrite existing BCache sets
:param attach: Attach all existing backend devices immediately
'''
# TODO: multiple devs == md jbod
# pylint: disable=too-many-return-statements
# ---------------- Preflight checks ----------------
cache = uuid()
if cache:
if not force:
log.error('BCache cache %s is already on the system', cache)
return False
cache = _bdev()
dev = _devbase(dev)
udev = __salt__['udev.env'](dev)
if ('ID_FS_TYPE' in udev or (udev.get('DEVTYPE', None) != 'partition' and 'ID_PART_TABLE_TYPE' in udev)) \
and not force:
log.error('%s already contains data, wipe first or force', dev)
return False
elif reserved is not None and udev.get('DEVTYPE', None) != 'disk':
log.error('Need a partitionable blockdev for reserved to work')
return False
_, block, bucket = _sizes(dev)
if bucket_size is None:
bucket_size = bucket
# TODO: bucket from _sizes() makes no sense
bucket_size = False
if block_size is None:
block_size = block
# ---------------- Still here, start doing destructive stuff ----------------
if cache:
if not stop():
return False
# Wipe the current cache device as well,
# forever ruining any chance of it accidentally popping up again
elif not _wipe(cache):
return False
# Can't do enough wiping
if not _wipe(dev):
return False
if reserved:
cmd = 'parted -m -s -a optimal -- ' \
'/dev/{0} mklabel gpt mkpart bcache-reserved 1M {1} mkpart bcache {1} 100%'.format(dev, reserved)
# if wipe was incomplete & part layout remains the same,
# this is one condition set where udev would make it accidentally popup again
if not _run_all(cmd, 'error', 'Error creating bcache partitions on {0}: %s'.format(dev)):
return False
dev = '{0}2'.format(dev)
# ---------------- Finally, create a cache ----------------
cmd = 'make-bcache --cache /dev/{0} --block {1} --wipe-bcache'.format(dev, block_size)
# Actually bucket_size should always have a value, but for testing 0 is possible as well
if bucket_size:
cmd += ' --bucket {0}'.format(bucket_size)
if not _run_all(cmd, 'error', 'Error creating cache {0}: %s'.format(dev)):
return False
elif not _wait(lambda: uuid() is not False,
'error', 'Cache {0} seemingly created OK, but FS did not activate'.format(dev)):
return False
if attach:
return _alltrue(attach_())
else:
return True
def config_(dev=None, **kwargs):
'''
Show or update config of a bcache device.
If no device is given, operate on the cache set itself.
CLI example:
.. code-block:: bash
salt '*' bcache.config
salt '*' bcache.config bcache1
salt '*' bcache.config errors=panic journal_delay_ms=150
salt '*' bcache.config bcache1 cache_mode=writeback writeback_percent=15
:return: config or True/False
'''
if dev is None:
spath = _fspath()
else:
spath = _bcpath(dev)
# filter out 'hidden' kwargs added by our favourite orchestration system
updates = dict([(key, val) for key, val in kwargs.items() if not key.startswith('__')])
if updates:
endres = 0
for key, val in updates.items():
endres += _sysfs_attr([spath, key], val,
'warn', 'Failed to update {0} with {1}'.format(os.path.join(spath, key), val))
return endres > 0
else:
result = {}
data = _sysfs_parse(spath, config=True, internals=True, options=True)
for key in ('other_ro', 'inter_ro'):
if key in data:
del data[key]
for key in data:
result.update(data[key])
return result
def status(stats=False, config=False, internals=False, superblock=False, alldevs=False):
'''
Show the full status of the BCache system and optionally all it's involved devices
CLI example:
.. code-block:: bash
salt '*' bcache.status
salt '*' bcache.status stats=True
salt '*' bcache.status internals=True alldevs=True
:param stats: include statistics
:param config: include settings
:param internals: include internals
:param superblock: include superblock
'''
bdevs = []
for _, links, _ in salt.utils.path.os_walk('/sys/block/'):
for block in links:
if 'bcache' in block:
continue
for spath, sdirs, _ in salt.utils.path.os_walk('/sys/block/{0}'.format(block), followlinks=False):
if 'bcache' in sdirs:
bdevs.append(os.path.basename(spath))
statii = {}
for bcache in bdevs:
statii[bcache] = device(bcache, stats, config, internals, superblock)
cuuid = uuid()
cdev = _bdev()
if cdev:
count = 0
for dev in statii:
if dev != cdev:
# it's a backing dev
if statii[dev]['cache'] == cuuid:
count += 1
statii[cdev]['attached_backing_devices'] = count
if not alldevs:
statii = statii[cdev]
return statii
def device(dev, stats=False, config=False, internals=False, superblock=False):
'''
Check the state of a single bcache device
CLI example:
.. code-block:: bash
salt '*' bcache.device bcache0
salt '*' bcache.device /dev/sdc stats=True
:param stats: include statistics
:param settings: include all settings
:param internals: include all internals
:param superblock: include superblock info
'''
result = {}
if not _sysfs_attr(_bcpath(dev), None, 'error', '{0} is not a bcache fo any kind'.format(dev)):
return False
elif _bcsys(dev, 'set'):
# ---------------- It's the cache itself ----------------
result['uuid'] = uuid()
base_attr = ['block_size', 'bucket_size', 'cache_available_percent', 'cache_replacement_policy', 'congested']
# ---------------- Parse through both the blockdev & the FS ----------------
result.update(_sysfs_parse(_bcpath(dev), base_attr, stats, config, internals))
result.update(_sysfs_parse(_fspath(), base_attr, stats, config, internals))
result.update(result.pop('base'))
else:
# ---------------- It's a backing device ----------------
back_uuid = uuid(dev)
if back_uuid is not None:
result['cache'] = back_uuid
try:
result['dev'] = os.path.basename(_bcsys(dev, 'dev'))
except Exception:
pass
result['bdev'] = _bdev(dev)
base_attr = ['cache_mode', 'running', 'state', 'writeback_running']
base_path = _bcpath(dev)
result.update(_sysfs_parse(base_path, base_attr, stats, config, internals))
result.update(result.pop('base'))
# ---------------- Modifications ----------------
state = [result['state']]
if result.pop('running'):
state.append('running')
else:
state.append('stopped')
if 'writeback_running' in result:
if result.pop('writeback_running'):
state.append('writeback_running')
else:
state.append('writeback_stopped')
result['state'] = state
# ---------------- Statistics ----------------
if 'stats' in result:
replre = r'(stats|cache)_'
statres = result['stats']
for attr in result['stats']:
if '/' not in attr:
key = re.sub(replre, '', attr)
statres[key] = statres.pop(attr)
else:
stat, key = attr.split('/', 1)
stat = re.sub(replre, '', stat)
key = re.sub(replre, '', key)
if stat not in statres:
statres[stat] = {}
statres[stat][key] = statres.pop(attr)
result['stats'] = statres
# ---------------- Internals ----------------
if internals:
interres = result.pop('inter_ro', {})
interres.update(result.pop('inter_rw', {}))
if interres:
for key in interres:
if key.startswith('internal'):
nkey = re.sub(r'internal[s/]*', '', key)
interres[nkey] = interres.pop(key)
key = nkey
if key.startswith(('btree', 'writeback')):
mkey, skey = re.split(r'_', key, maxsplit=1)
if mkey not in interres:
interres[mkey] = {}
interres[mkey][skey] = interres.pop(key)
result['internals'] = interres
# ---------------- Config ----------------
if config:
configres = result['config']
for key in configres:
if key.startswith('writeback'):
mkey, skey = re.split(r'_', key, maxsplit=1)
if mkey not in configres:
configres[mkey] = {}
configres[mkey][skey] = configres.pop(key)
result['config'] = configres
# ---------------- Superblock ----------------
if superblock:
result['superblock'] = super_(dev)
return result
def super_(dev):
'''
Read out BCache SuperBlock
CLI example:
.. code-block:: bash
salt '*' bcache.device bcache0
salt '*' bcache.device /dev/sdc
'''
dev = _devpath(dev)
ret = {}
res = _run_all('bcache-super-show {0}'.format(dev), 'error', 'Error reading superblock on {0}: %s'.format(dev))
if not res:
return False
for line in res.splitlines(): # pylint: disable=no-member
line = line.strip()
if not line:
continue
key, val = [val.strip() for val in re.split(r'[\s]+', line, maxsplit=1)]
if not (key and val):
continue
mval = None
if ' ' in val:
rval, mval = [val.strip() for val in re.split(r'[\s]+', val, maxsplit=1)]
mval = mval[1:-1]
else:
rval = val
try:
rval = int(rval)
except Exception:
try:
rval = float(rval)
except Exception:
if rval == 'yes':
rval = True
elif rval == 'no':
rval = False
pkey, key = re.split(r'\.', key, maxsplit=1)
if pkey not in ret:
ret[pkey] = {}
if mval is not None:
ret[pkey][key] = (rval, mval)
else:
ret[pkey][key] = rval
return ret
# -------------------------------- HELPER FUNCTIONS --------------------------------
def _devbase(dev):
'''
Basename of just about any dev
'''
dev = os.path.realpath(os.path.expandvars(dev))
dev = os.path.basename(dev)
return dev
def _devpath(dev):
'''
Return /dev name of just about any dev
:return: /dev/devicename
'''
return os.path.join('/dev', _devbase(dev))
def _syspath(dev):
'''
Full SysFS path of a device
'''
dev = _devbase(dev)
dev = re.sub(r'^([vhs][a-z]+)([0-9]+)', r'\1/\1\2', dev)
# name = re.sub(r'^([a-z]+)(?<!(bcache|md|dm))([0-9]+)', r'\1/\1\2', name)
return os.path.join('/sys/block/', dev)
def _bdev(dev=None):
'''
Resolve a bcacheX or cache to a real dev
:return: basename of bcache dev
'''
if dev is None:
dev = _fssys('cache0')
else:
dev = _bcpath(dev)
if not dev:
return False
else:
return _devbase(os.path.dirname(dev))
def _bcpath(dev):
'''
Full SysFS path of a bcache device
'''
return os.path.join(_syspath(dev), 'bcache')
def _fspath():
'''
:return: path of active bcache
'''
cuuid = uuid()
if not cuuid:
return False
else:
return os.path.join('/sys/fs/bcache/', cuuid)
def _fssys(name, value=None, log_lvl=None, log_msg=None):
'''
Simple wrapper to interface with bcache SysFS
'''
fspath = _fspath()
if not fspath:
return False
else:
return _sysfs_attr([fspath, name], value, log_lvl, log_msg)
def _bcsys(dev, name, value=None, log_lvl=None, log_msg=None):
'''
Simple wrapper to interface with backing devs SysFS
'''
return _sysfs_attr([_bcpath(dev), name], value, log_lvl, log_msg)
def _sysfs_attr(name, value=None, log_lvl=None, log_msg=None):
'''
Simple wrapper with logging around sysfs.attr
'''
if isinstance(name, six.string_types):
name = [name]
res = __salt__['sysfs.attr'](os.path.join(*name), value)
if not res and log_lvl is not None and log_msg is not None:
log.log(LOG[log_lvl], log_msg)
return res
def _sysfs_parse(path, base_attr=None, stats=False, config=False, internals=False, options=False):
'''
Helper function for parsing BCache's SysFS interface
'''
result = {}
# ---------------- Parse through the interfaces list ----------------
intfs = __salt__['sysfs.interfaces'](path)
# Actions, we ignore
del intfs['w']
# -------- Sorting hat --------
binkeys = []
if internals:
binkeys.extend(['inter_ro', 'inter_rw'])
if config:
binkeys.append('config')
if stats:
binkeys.append('stats')
bintf = {}
for key in binkeys:
bintf[key] = []
for intf in intfs['r']:
if intf.startswith('internal'):
key = 'inter_ro'
elif 'stats' in intf:
key = 'stats'
else:
# What to do with these???
# I'll utilize 'inter_ro' as 'misc' as well
key = 'inter_ro'
if key in bintf:
bintf[key].append(intf)
for intf in intfs['rw']:
if intf.startswith('internal'):
key = 'inter_rw'
else:
key = 'config'
if key in bintf:
bintf[key].append(intf)
if base_attr is not None:
for intf in bintf:
bintf[intf] = [sintf for sintf in bintf[intf] if sintf not in base_attr]
bintf['base'] = base_attr
mods = {
'stats': ['internal/bset_tree_stats', 'writeback_rate_debug', 'metadata_written', 'nbuckets', 'written',
'average_key_size', 'btree_cache_size'],
}
for modt, modlist in mods.items():
found = []
if modt not in bintf:
continue
for mod in modlist:
for intflist in bintf.values():
if mod in intflist:
found.append(mod)
intflist.remove(mod)
bintf[modt] += found
# -------- Fetch SysFS vals --------
bintflist = [intf for iflist in bintf.values() for intf in iflist]
result.update(__salt__['sysfs.read'](bintflist, path))
# -------- Parse through well known string lists --------
for strlist in ('writeback_rate_debug', 'internal/bset_tree_stats', 'priority_stats'):
if strlist in result:
listres = {}
for line in result[strlist].split('\n'):
key, val = line.split(':', 1)
val = val.strip()
try:
val = int(val)
except Exception:
try:
val = float(val)
except Exception:
pass
listres[key.strip()] = val
result[strlist] = listres
# -------- Parse through selection lists --------
if not options:
for sellist in ('cache_mode', 'cache_replacement_policy', 'errors'):
if sellist in result:
result[sellist] = re.search(r'\[(.+)\]', result[sellist]).groups()[0]
# -------- Parse through well known bools --------
for boolkey in ('running', 'writeback_running', 'congested'):
if boolkey in result:
result[boolkey] = bool(result[boolkey])
# -------- Recategorize results --------
bresult = {}
for iftype, intflist in bintf.items():
ifres = {}
for intf in intflist:
if intf in result:
ifres[intf] = result.pop(intf)
if ifres:
bresult[iftype] = ifres
return bresult
def _size_map(size):
'''
Map Bcache's size strings to real bytes
'''
try:
# I know, I know, EAFP.
# But everything else is reason for None
if not isinstance(size, int):
if re.search(r'[Kk]', size):
size = 1024 * float(re.sub(r'[Kk]', '', size))
elif re.search(r'[Mm]', size):
size = 1024**2 * float(re.sub(r'[Mm]', '', size))
size = int(size)
return size
except Exception:
return None
def _sizes(dev):
'''
Return neigh useless sizing info about a blockdev
:return: (total size in blocks, blocksize, maximum discard size in bytes)
'''
dev = _devbase(dev)
# standarization yay
block_sizes = ('hw_sector_size', 'minimum_io_size', 'physical_block_size', 'logical_block_size')
discard_sizes = ('discard_max_bytes', 'discard_max_hw_bytes', )
sysfs = __salt__['sysfs.read'](
('size',
'queue/hw_sector_size', '../queue/hw_sector_size',
'queue/discard_max_bytes', '../queue/discard_max_bytes'),
root=_syspath(dev))
# TODO: makes no sense
# First of all, it has to be a power of 2
# Secondly, this returns 4GiB - 512b on Intel 3500's for some weird reason
# discard_granularity seems in bytes, resolves to 512b ???
# max_hw_sectors_kb???
# There's also discard_max_hw_bytes more recently
# See: https://www.kernel.org/doc/Documentation/block/queue-sysfs.txt
# Also, I cant find any docs yet regarding bucket sizes;
# it's supposed to be discard_max_hw_bytes,
# but no way to figure that one reliably out apparently
discard = sysfs.get('queue/discard_max_bytes', sysfs.get('../queue/discard_max_bytes', None))
block = sysfs.get('queue/hw_sector_size', sysfs.get('../queue/hw_sector_size', None))
return 512*sysfs['size'], block, discard
def _wipe(dev):
'''
REALLY DESTRUCTIVE STUFF RIGHT AHEAD
'''
endres = 0
dev = _devbase(dev)
size, block, discard = _sizes(dev)
if discard is None:
log.error('Unable to read SysFS props for %s', dev)
return None
elif not discard:
log.warning('%s seems unable to discard', dev)
wiper = 'dd'
elif not HAS_BLKDISCARD:
log.warning('blkdiscard binary not available, properly wipe the dev manually for optimal results')
wiper = 'dd'
else:
wiper = 'blkdiscard'
wipe_failmsg = 'Error wiping {0}: %s'.format(dev)
if wiper == 'dd':
blocks = 4
cmd = 'dd if=/dev/zero of=/dev/{0} bs=1M count={1}'.format(dev, blocks)
endres += _run_all(cmd, 'warn', wipe_failmsg)
# Some stuff (<cough>GPT</cough>) writes stuff at the end of a dev as well
cmd += ' seek={0}'.format((size/1024**2) - blocks)
endres += _run_all(cmd, 'warn', wipe_failmsg)
elif wiper == 'blkdiscard':
cmd = 'blkdiscard /dev/{0}'.format(dev)
endres += _run_all(cmd, 'warn', wipe_failmsg)
# TODO: fix annoying bug failing blkdiscard by trying to discard 1 sector past blkdev
endres = 1
return endres > 0
def _wait(lfunc, log_lvl=None, log_msg=None, tries=10):
'''
Wait for lfunc to be True
:return: True if lfunc succeeded within tries, False if it didn't
'''
i = 0
while i < tries:
time.sleep(1)
if lfunc():
return True
else:
i += 1
if log_lvl is not None:
log.log(LOG[log_lvl], log_msg)
return False
def _run_all(cmd, log_lvl=None, log_msg=None, exitcode=0):
'''
Simple wrapper around cmd.run_all
log_msg can contain {0} for stderr
:return: True or stdout, False if retcode wasn't exitcode
'''
res = __salt__['cmd.run_all'](cmd)
if res['retcode'] == exitcode:
if res['stdout']:
return res['stdout']
else:
return True
if log_lvl is not None:
log.log(LOG[log_lvl], log_msg, res['stderr'])
return False
def _alltrue(resdict):
if resdict is None:
return True
return len([val for val in resdict.values() if val]) > 0