# Copyright 2013 Rackspace, Inc.
#
# 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 copy
import glob
import os
import shutil
import tempfile
from oslo_concurrency import processutils
from oslo_log import log as logging
from oslo_utils import units
from six.moves.urllib import parse
from ironic_python_agent import errors
LOG = logging.getLogger(__name__)
SUPPORTED_ROOT_DEVICE_HINTS = set(('size', 'model', 'wwn', 'serial', 'vendor',
'wwn_with_extension',
'wwn_vendor_extension'))
# Agent parameters can be passed by kernel command-line arguments and/or
# by virtual media. Virtual media parameters passed would be available
# when the agent is started, but might not be available for re-reading
# later on because:
# * Virtual media might be exposed from Swift and swift temp url might
# expire.
# * Ironic might have removed the floppy image from Swift after starting
# the deploy.
#
# Even if it's available, there is no need to re-read from the device and
# /proc/cmdline again, because it is never going to change. So we cache the
# agent parameters that was passed (by proc/cmdline and/or virtual media)
# when we read it for the first time, and then use this cache.
AGENT_PARAMS_CACHED = dict()
def execute(*cmd, **kwargs):
"""Convenience wrapper around oslo's execute() method.
Executes and logs results from a system command. See docs for
oslo_concurrency.processutils.execute for usage.
:param *cmd: positional arguments to pass to processutils.execute()
:param log_stdout: keyword-only argument: whether to log the output
:param **kwargs: keyword arguments to pass to processutils.execute()
:raises: UnknownArgumentError on receiving unknown arguments
:raises: ProcessExecutionError
:raises: OSError
:returns: tuple of (stdout, stderr)
"""
log_stdout = kwargs.pop('log_stdout', True)
result = processutils.execute(*cmd, **kwargs)
LOG.debug('Execution completed, command line is "%s"', ' '.join(cmd))
if log_stdout:
LOG.debug('Command stdout is: "%s"', result[0])
LOG.debug('Command stderr is: "%s"', result[1])
return result
def try_execute(*cmd, **kwargs):
"""The same as execute but returns None on error.
Executes and logs results from a system command. See docs for
oslo_concurrency.processutils.execute for usage.
Instead of raising an exception on failure, this method simply
returns None in case of failure.
:param *cmd: positional arguments to pass to processutils.execute()
:param log_stdout: keyword-only argument: whether to log the output
:param **kwargs: keyword arguments to pass to processutils.execute()
:raises: UnknownArgumentError on receiving unknown arguments
:returns: tuple of (stdout, stderr) or None in some error cases
"""
try:
return execute(*cmd, **kwargs)
except (processutils.ProcessExecutionError, OSError) as e:
LOG.debug('Command failed: %s', e)
def _read_params_from_file(filepath):
"""Extract key=value pairs from a file.
:param filepath: path to a file containing key=value pairs separated by
whitespace or newlines.
:returns: a dictionary representing the content of the file
"""
with open(filepath) as f:
cmdline = f.read()
options = cmdline.split()
params = {}
for option in options:
if '=' not in option:
continue
k, v = option.split('=', 1)
params[k] = v
return params
def _get_vmedia_device():
"""Finds the device filename of the virtual media device using sysfs.
:returns: a string containing the filename of the virtual media device
"""
sysfs_device_models = glob.glob("/sys/class/block/*/device/model")
vmedia_device_model = "virtual media"
for model_file in sysfs_device_models:
try:
with open(model_file) as model_file_fobj:
if vmedia_device_model in model_file_fobj.read().lower():
vmedia_device = model_file.split('/')[4]
return vmedia_device
except Exception:
pass
def _get_vmedia_params():
"""This method returns the parameters passed through virtual media floppy.
:returns: a partial dict of potential agent configuration parameters
:raises: VirtualMediaBootError when it cannot find the virtual media device
"""
parameters_file = "parameters.txt"
vmedia_device_file_lower_case = "/dev/disk/by-label/ir-vfd-dev"
vmedia_device_file_upper_case = "/dev/disk/by-label/IR-VFD-DEV"
if os.path.exists(vmedia_device_file_lower_case):
vmedia_device_file = vmedia_device_file_lower_case
elif os.path.exists(vmedia_device_file_upper_case):
vmedia_device_file = vmedia_device_file_upper_case
else:
# TODO(rameshg87): This block of code is there only for compatibility
# reasons (so that newer agent can work with older Ironic). Remove
# this after Liberty release.
vmedia_device = _get_vmedia_device()
if not vmedia_device:
msg = "Unable to find virtual media device"
raise errors.VirtualMediaBootError(msg)
vmedia_device_file = os.path.join("/dev", vmedia_device)
vmedia_mount_point = tempfile.mkdtemp()
try:
try:
stdout, stderr = execute("mount", vmedia_device_file,
vmedia_mount_point)
except processutils.ProcessExecutionError as e:
msg = ("Unable to mount virtual media device %(device)s: "
"%(error)s" % {'device': vmedia_device_file, 'error': e})
raise errors.VirtualMediaBootError(msg)
parameters_file_path = os.path.join(vmedia_mount_point,
parameters_file)
params = _read_params_from_file(parameters_file_path)
try:
stdout, stderr = execute("umount", vmedia_mount_point)
except processutils.ProcessExecutionError as e:
pass
finally:
try:
shutil.rmtree(vmedia_mount_point)
except Exception as e:
pass
return params
def _get_cached_params():
"""Helper method to get cached params to ease unit testing."""
return AGENT_PARAMS_CACHED
def _set_cached_params(params):
"""Helper method to set cached params to ease unit testing."""
global AGENT_PARAMS_CACHED
AGENT_PARAMS_CACHED = params
def get_agent_params():
"""Gets parameters passed to the agent via kernel cmdline or vmedia.
Parameters can be passed using either the kernel commandline or through
virtual media. If boot_method is vmedia, merge params provided via vmedia
with those read from the kernel command line.
Although it should never happen, if a variable is both set by vmedia and
kernel command line, the setting in vmedia will take precedence.
:returns: a dict of potential configuration parameters for the agent
"""
# Check if we have the parameters cached
params = _get_cached_params()
if not params:
params = _read_params_from_file('/proc/cmdline')
# If the node booted over virtual media, the parameters are passed
# in a text file within the virtual media floppy.
if params.get('boot_method') == 'vmedia':
vmedia_params = _get_vmedia_params()
params.update(vmedia_params)
# Cache the parameters so that it can be used later on.
_set_cached_params(params)
return copy.deepcopy(params)
def normalize(string):
"""Return a normalized string.
Take a urlencoded value from Ironic and urldecode it.
:param string: a urlencoded string
:returns: a normalized version of passed in string
"""
return parse.unquote(string).lower().strip()
def parse_root_device_hints():
"""Parse the root device hints.
Parse the root device hints given by Ironic via kernel cmdline
or vmedia.
:returns: A dict with the hints or an empty dict if no hints are
passed.
:raises: DeviceNotFound if there are unsupported hints.
"""
root_device = get_agent_params().get('root_device')
if not root_device:
return {}
hints = dict((item.split('=') for item in root_device.split(',')))
# Find invalid hints for logging
not_supported = set(hints) - SUPPORTED_ROOT_DEVICE_HINTS
if not_supported:
error_msg = ('No device can be found because the following hints: '
'"%(not_supported)s" are not supported by this version '
'of IPA. Supported hints are: "%(supported)s"',
{'not_supported': ', '.join(not_supported),
'supported': ', '.join(SUPPORTED_ROOT_DEVICE_HINTS)})
raise errors.DeviceNotFound(error_msg)
# Normalise the values
hints = {k: normalize(v) for k, v in hints.items()}
if 'size' in hints:
# NOTE(lucasagomes): Ironic should validate before passing to
# the deploy ramdisk
hints['size'] = int(hints['size'])
return hints
[docs]class AccumulatedFailures(object):
"""Object to accumulate failures without raising exception."""
def __init__(self, exc_class=RuntimeError):
self._failures = []
self._exc_class = exc_class
[docs] def add(self, fail, *fmt):
"""Add failure with optional formatting.
:param fail: exception or error string
:param fmt: formatting arguments (only if fail is a string)
"""
if fmt:
fail = fail % fmt
LOG.error('%s', fail)
self._failures.append(fail)
[docs] def get_error(self):
"""Get error string or None."""
if not self._failures:
return
msg = ('The following errors were encountered:\n%s'
% '\n'.join('* %s' % item for item in self._failures))
return msg
[docs] def raise_if_needed(self):
"""Raise exception if error list is not empty.
:raises: RuntimeError
"""
if self._failures:
raise self._exc_class(self.get_error())
def __nonzero__(self):
return bool(self._failures)
__bool__ = __nonzero__
def __repr__(self): # pragma: no cover
# This is for tests
if self:
return '<%s: %s>' % (self.__class__.__name__,
', '.join(self._failures))
else:
return '<%s: success>' % self.__class__.__name__
def guess_root_disk(block_devices, min_size_required=4 * units.Gi):
"""Find suitable disk provided that root device hints are not given.
If no hints are passed find the first device larger than min_size_required,
assume it is the OS disk
"""
# TODO(russellhaering): This isn't a valid assumption in
# all cases, is there a more reasonable default behavior?
block_devices.sort(key=lambda device: device.size)
if not block_devices or block_devices[-1].size < min_size_required:
raise errors.DeviceNotFound(
"No suitable device was found "
"for deployment - root device hints were not provided "
"and all found block devices are smaller than %iB."
% min_size_required)
for device in block_devices:
if device.size >= min_size_required:
return device