# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 Nicira Networks, 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.
"""
System-level utilities and helper functions.
"""
import ConfigParser
import datetime
import exceptions as exception
import flags
import inspect
import logging
import os
import random
import subprocess
import socket
import sys
from exceptions import ProcessExecutionError
TIME_FORMAT = "%Y-%m-%dT%H:%M:%SZ"
FLAGS = flags.FLAGS
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 type(subject) == type(bool):
return subject
if hasattr(subject, 'startswith'): # str or unicode...
if subject.strip().lower() in ('true', 'on', '1'):
return True
return False
def import_class(import_str):
"""Returns a class from a string including module and class"""
mod_str, _sep, class_str = import_str.rpartition('.')
try:
#mod_str = os.path.join(FLAGS.state_path, mod_str)
__import__(mod_str)
return getattr(sys.modules[mod_str], class_str)
except (ImportError, ValueError, AttributeError) as e:
print e
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:
cls = import_class(import_str)
return cls()
def fetchfile(url, target):
logging.debug("Fetching %s" % url)
# c = pycurl.Curl()
# fp = open(target, "wb")
# c.setopt(c.URL, url)
# c.setopt(c.WRITEDATA, fp)
# c.perform()
# c.close()
# fp.close()
execute("curl --fail %s -o %s" % (url, target))
def execute(cmd, process_input=None, addl_env=None, check_exit_code=True):
logging.debug("Running cmd: %s", cmd)
env = os.environ.copy()
if addl_env:
env.update(addl_env)
obj = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE,
stdout=subprocess.PIPE, stderr=subprocess.PIPE, env=env)
result = None
if process_input != None:
result = obj.communicate(process_input)
else:
result = obj.communicate()
obj.stdin.close()
if obj.returncode:
logging.debug("Result was %s" % (obj.returncode))
if check_exit_code and obj.returncode != 0:
(stdout, stderr) = result
raise ProcessExecutionError(exit_code=obj.returncode,
stdout=stdout,
stderr=stderr,
cmd=cmd)
return result
def abspath(s):
return os.path.join(os.path.dirname(__file__), s)
# TODO(sirp): when/if utils is extracted to common library, we should remove
# the argument's default.
#def default_flagfile(filename='nova.conf'):
def default_flagfile(filename='quantum.conf'):
for arg in sys.argv:
if arg.find('flagfile') != -1:
break
else:
if not os.path.isabs(filename):
# turn relative filename into an absolute path
script_dir = os.path.dirname(inspect.stack()[-1][1])
filename = os.path.abspath(os.path.join(script_dir, filename))
if os.path.exists(filename):
sys.argv = \
sys.argv[:1] + ['--flagfile=%s' % filename] + sys.argv[1:]
def debug(arg):
logging.debug('debug in callback: %s', arg)
return arg
def runthis(prompt, cmd, check_exit_code=True):
logging.debug("Running %s" % (cmd))
exit_code = subprocess.call(cmd.split(" "))
logging.debug(prompt % (exit_code))
if check_exit_code and exit_code != 0:
raise ProcessExecutionError(exit_code=exit_code,
stdout=None,
stderr=None,
cmd=cmd)
def generate_uid(topic, size=8):
return '%s-%s' % (topic, ''.join(
[random.choice('01234567890abcdefghijklmnopqrstuvwxyz')
for x in xrange(size)]))
def generate_mac():
mac = [0x02, 0x16, 0x3e, random.randint(0x00, 0x7f),
random.randint(0x00, 0xff), random.randint(0x00, 0xff)]
return ':'.join(map(lambda x: "%02x" % x, mac))
def last_octet(address):
return int(address.split(".")[-1])
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 get_plugin_from_config(file="config.ini"):
Config = ConfigParser.ConfigParser()
Config.read(file)
return Config.get("PLUGIN", "provider")
class LazyPluggable(object):
"""A pluggable backend loaded lazily based on some value."""
def __init__(self, pivot, **backends):
self.__backends = backends
self.__pivot = pivot
self.__backend = None
def __get_backend(self):
if not self.__backend:
backend_name = self.__pivot.value
if backend_name not in self.__backends:
raise exception.Error('Invalid backend: %s' % backend_name)
backend = self.__backends[backend_name]
if type(backend) == type(tuple()):
name = backend[0]
fromlist = backend[1]
else:
name = backend
fromlist = backend
self.__backend = __import__(name, None, None, fromlist)
logging.info('backend %s', self.__backend)
return self.__backend
def __getattr__(self, key):
backend = self.__get_backend()
return getattr(backend, key)