# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 OpenStack LLC.
# 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.
"""
System-level utilities and helper functions.
"""
import datetime
import logging
import os
import random
import shlex
import sys
import types
from eventlet import greenthread
from eventlet.green import subprocess
from openstack.common import exception
TIME_FORMAT = "%Y-%m-%dT%H:%M:%SZ"
LOG = logging.getLogger(__name__)
def int_from_bool_as_string(subject):
"""
Interpret a string as a boolean and return either 1 or 0.
Any string value in:
('True', 'true', 'On', 'on', '1')
is interpreted as a boolean True.
Useful for JSON-decoded stuff and config file parsing
"""
return bool_from_string(subject) and 1 or 0
def bool_from_string(subject):
"""
Interpret a string as a boolean.
Any string value in:
('True', 'true', 'On', 'on', '1')
is interpreted as a boolean True.
Useful for JSON-decoded stuff and config file parsing
"""
if isinstance(subject, types.BooleanType):
return subject
if isinstance(subject, types.StringTypes):
if subject.strip().lower() in ('true', 'on', '1'):
return True
return False
def execute(*cmd, **kwargs):
"""
Helper method to execute command with optional retry.
:cmd Passed to subprocess.Popen.
:process_input Send to opened process.
:check_exit_code Defaults to 0. Raise exception.ProcessExecutionError
unless program exits with this code.
:delay_on_retry True | False. Defaults to True. If set to True, wait a
short amount of time before retrying.
:attempts How many times to retry cmd.
:run_as_root True | False. Defaults to False. If set to True,
the command is prefixed by the command specified
in the root_helper kwarg.
:root_helper command to prefix all cmd's with
:raises exception.Error on receiving unknown arguments
:raises exception.ProcessExecutionError
"""
process_input = kwargs.pop('process_input', None)
check_exit_code = kwargs.pop('check_exit_code', 0)
delay_on_retry = kwargs.pop('delay_on_retry', True)
attempts = kwargs.pop('attempts', 1)
run_as_root = kwargs.pop('run_as_root', False)
root_helper = kwargs.pop('root_helper', '')
if len(kwargs):
raise exception.Error(_('Got unknown keyword args '
'to utils.execute: %r') % kwargs)
if run_as_root:
cmd = shlex.split(root_helper) + list(cmd)
cmd = map(str, cmd)
while attempts > 0:
attempts -= 1
try:
LOG.debug(_('Running cmd (subprocess): %s'), ' '.join(cmd))
_PIPE = subprocess.PIPE # pylint: disable=E1101
obj = subprocess.Popen(cmd,
stdin=_PIPE,
stdout=_PIPE,
stderr=_PIPE,
close_fds=True)
result = None
if process_input is not None:
result = obj.communicate(process_input)
else:
result = obj.communicate()
obj.stdin.close() # pylint: disable=E1101
_returncode = obj.returncode # pylint: disable=E1101
if _returncode:
LOG.debug(_('Result was %s') % _returncode)
if type(check_exit_code) == types.IntType \
and _returncode != check_exit_code:
(stdout, stderr) = result
raise exception.ProcessExecutionError(
exit_code=_returncode,
stdout=stdout,
stderr=stderr,
cmd=' '.join(cmd))
return result
except exception.ProcessExecutionError:
if not attempts:
raise
else:
LOG.debug(_('%r failed. Retrying.'), cmd)
if delay_on_retry:
greenthread.sleep(random.randint(20, 200) / 100.0)
finally:
# NOTE(termie): this appears to be necessary to let the subprocess
# call clean something up in between calls, without
# it two execute calls in a row hangs the second one
greenthread.sleep(0)
def import_class(import_str):
"""Returns a class from a string including module and class"""
mod_str, _sep, class_str = import_str.rpartition('.')
try:
__import__(mod_str)
return getattr(sys.modules[mod_str], class_str)
except (ImportError, ValueError, AttributeError):
raise exception.NotFound('Class %s cannot be found' % class_str)
def import_object(import_str):
"""Returns an object including a module or module and class"""
try:
__import__(import_str)
return sys.modules[import_str]
except ImportError:
return import_class(import_str)
def isotime(at=None):
if not at:
at = datetime.datetime.utcnow()
return at.strftime(TIME_FORMAT)
def parse_isotime(timestr):
return datetime.datetime.strptime(timestr, TIME_FORMAT)
def parse_mailmap(mailmap='.mailmap'):
mapping = {}
if os.path.exists(mailmap):
fp = open(mailmap, 'r')
for l in fp:
l = l.strip()
if not l.startswith('#') and ' ' in l:
canonical_email, alias = l.split(' ')
mapping[alias] = canonical_email
return mapping
def str_dict_replace(s, mapping):
for s1, s2 in mapping.iteritems():
s = s.replace(s1, s2)
return s
def utcnow():
"""Overridable version of utils.utcnow."""
if utcnow.override_time:
return utcnow.override_time
return datetime.datetime.utcnow()
utcnow.override_time = None
def set_time_override(override_time=datetime.datetime.utcnow()):
"""Override utils.utcnow to return a constant time."""
utcnow.override_time = override_time
def clear_time_override():
"""Remove the overridden time."""
utcnow.override_time = None