vmware-nsx/quantum/common/utils.py
gongysh 00897bd3b7 Add scheduling feature basing on agent management extension
3rd part of blueprint quantum-scheduler

1. Allow networks to be hosted by certain dhcp agents.
Network to dhcp agent is a
many to many relationship. Provide a simple
scheduler to schedule a network randomly
to an active dhcp agent when a network or port is created.
2. Allow admin user to (de)schedule network to a
certain dhcp agent manually.
3. Allow routers to be hosted by a certain l3 agent.
Router to l3 agent is a many to one relationship.
Provide a simple scheduler to
schedule a router to l3 agent if the router is not
scheduled when the router is  updated.
4. Auto schedule networks and routers to agents when agents
start.
5. Only support ovs plugin at this point

Change-Id: Iddec3ea9d4c0fe2d51a59f7db47145722fc5a1cd
2013-02-27 21:20:51 +08:00

191 lines
6.4 KiB
Python

# 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.
#
# Borrowed from nova code base, more utilities will be added/borrowed as and
# when needed.
# @author: Somik Behera, Nicira Networks, Inc.
"""Utilities and helper functions."""
import os
import signal
import socket
from eventlet.green import subprocess
from oslo.config import cfg
from quantum.openstack.common import log as logging
TIME_FORMAT = "%Y-%m-%dT%H:%M:%SZ"
LOG = logging.getLogger(__name__)
def read_cached_file(filename, cache_info, reload_func=None):
"""Read from a file if it has been modified.
:param cache_info: dictionary to hold opaque cache.
:param reload_func: optional function to be called with data when
file is reloaded due to a modification.
:returns: data from file
"""
mtime = os.path.getmtime(filename)
if not cache_info or mtime != cache_info.get('mtime'):
LOG.debug(_("Reloading cached file %s"), filename)
with open(filename) as fap:
cache_info['data'] = fap.read()
cache_info['mtime'] = mtime
if reload_func:
reload_func(cache_info['data'])
return cache_info['data']
def find_config_file(options, config_file):
"""
Return the first config file found.
We search for the paste config file in the following order:
* If --config-file option is used, use that
* Search for the configuration files via common cfg directories
:retval Full path to config file, or None if no config file found
"""
fix_path = lambda p: os.path.abspath(os.path.expanduser(p))
if options.get('config_file'):
if os.path.exists(options['config_file']):
return fix_path(options['config_file'])
dir_to_common = os.path.dirname(os.path.abspath(__file__))
root = os.path.join(dir_to_common, '..', '..', '..', '..')
# Handle standard directory search for the config file
config_file_dirs = [fix_path(os.path.join(os.getcwd(), 'etc')),
fix_path(os.path.join('~', '.quantum-venv', 'etc',
'quantum')),
fix_path('~'),
os.path.join(cfg.CONF.state_path, 'etc'),
os.path.join(cfg.CONF.state_path, 'etc', 'quantum'),
fix_path(os.path.join('~', '.local',
'etc', 'quantum')),
'/usr/etc/quantum',
'/usr/local/etc/quantum',
'/etc/quantum/',
'/etc']
if 'plugin' in options:
config_file_dirs = [
os.path.join(x, 'quantum', 'plugins', options['plugin'])
for x in config_file_dirs
]
if os.path.exists(os.path.join(root, 'plugins')):
plugins = [fix_path(os.path.join(root, 'plugins', p, 'etc'))
for p in os.listdir(os.path.join(root, 'plugins'))]
plugins = [p for p in plugins if os.path.isdir(p)]
config_file_dirs.extend(plugins)
for cfg_dir in config_file_dirs:
cfg_file = os.path.join(cfg_dir, config_file)
if os.path.exists(cfg_file):
return cfg_file
def _subprocess_setup():
# Python installs a SIGPIPE handler by default. This is usually not what
# non-Python subprocesses expect.
signal.signal(signal.SIGPIPE, signal.SIG_DFL)
def subprocess_popen(args, stdin=None, stdout=None, stderr=None, shell=False,
env=None):
return subprocess.Popen(args, shell=shell, stdin=stdin, stdout=stdout,
stderr=stderr, preexec_fn=_subprocess_setup,
close_fds=True, env=env)
def parse_mappings(mapping_list, unique_values=True):
"""Parse a list of of mapping strings into a dictionary.
:param mapping_list: a list of strings of the form '<key>:<value>'
:param unique_values: values must be unique if True
:returns: a dict mapping keys to values
"""
mappings = {}
for mapping in mapping_list:
mapping = mapping.strip()
if not mapping:
continue
split_result = mapping.split(':')
if len(split_result) != 2:
raise ValueError(_("Invalid mapping: '%s'") % mapping)
key = split_result[0].strip()
if not key:
raise ValueError(_("Missing key in mapping: '%s'") % mapping)
value = split_result[1].strip()
if not value:
raise ValueError(_("Missing value in mapping: '%s'") % mapping)
if key in mappings:
raise ValueError(_("Key %(key)s in mapping: '%(mapping)s' not "
"unique") % locals())
if unique_values and value in mappings.itervalues():
raise ValueError(_("Value %(value)s in mapping: '%(mapping)s' "
"not unique") % locals())
mappings[key] = value
return mappings
def get_hostname():
return socket.getfqdn()
def compare_elements(a, b):
""" compare elements if a and b have same elements
This method doesn't consider ordering
"""
if a is None:
a = []
if b is None:
b = []
return set(a) == set(b)
def dict2str(dic):
return ','.join("%s=%s" % (key, val)
for key, val in sorted(dic.iteritems()))
def str2dict(string):
res_dict = {}
for keyvalue in string.split(',', 1):
(key, value) = keyvalue.split('=', 1)
res_dict[key] = value
return res_dict
def diff_list_of_dict(old_list, new_list):
new_set = set([dict2str(l) for l in new_list])
old_set = set([dict2str(l) for l in old_list])
added = new_set - old_set
removed = old_set - new_set
return [str2dict(a) for a in added], [str2dict(r) for r in removed]
def is_extension_supported(plugin, ext_alias):
return ext_alias in getattr(
plugin, "supported_extension_aliases", [])