deb-heat/heat/engine/clients/__init__.py
LiuNanke 208d2debd0 Using LOG.warning replace LOG.warn
*Python 3 deprecated the logger.warn method, see:
*https://docs.python.org/3/library/logging.html#logging.warning
*so we prefer to use warning to avoid DeprecationWarning.

Change-Id: I07ee9c97c3548c965aaf83d34b37b23e9baba584
2015-12-29 09:32:42 +00:00

143 lines
4.4 KiB
Python

#
# 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 weakref
from oslo_config import cfg
from oslo_log import log as logging
from oslo_utils import importutils
import six
from stevedore import enabled
from heat.common import exception
from heat.common.i18n import _
from heat.common.i18n import _LW
LOG = logging.getLogger(__name__)
_default_backend = "heat.engine.clients.OpenStackClients"
cloud_opts = [
cfg.StrOpt('cloud_backend',
default=_default_backend,
help="Fully qualified class name to use as a client backend.")
]
cfg.CONF.register_opts(cloud_opts)
class OpenStackClients(object):
"""Convenience class to create and cache client instances."""
def __init__(self, context):
self._context = weakref.ref(context)
self._clients = {}
self._client_plugins = {}
@property
def context(self):
ctxt = self._context()
assert ctxt is not None, "Need a reference to the context"
return ctxt
def invalidate_plugins(self):
"""Used to force plugins to clear any cached client."""
for name in self._client_plugins:
self._client_plugins[name].invalidate()
def client_plugin(self, name):
global _mgr
if name in self._client_plugins:
return self._client_plugins[name]
if _mgr and name in _mgr.names():
client_plugin = _mgr[name].plugin(self.context)
self._client_plugins[name] = client_plugin
return client_plugin
def client(self, name):
client_plugin = self.client_plugin(name)
if client_plugin:
return client_plugin.client()
if name in self._clients:
return self._clients[name]
# call the local method _<name>() if a real client plugin
# doesn't exist
method_name = '_%s' % name
if callable(getattr(self, method_name, None)):
client = getattr(self, method_name)()
self._clients[name] = client
return client
LOG.warning(_LW('Requested client "%s" not found'), name)
@property
def auth_token(self):
# Always use the auth_token from the keystone() client, as
# this may be refreshed if the context contains credentials
# which allow reissuing of a new token before the context
# auth_token expiry (e.g trust_id or username/password)
return self.client('keystone').auth_token
class ClientBackend(object):
"""Class for delaying choosing the backend client module.
Delay choosing the backend client module until the client's class needs
to be initialized.
"""
def __new__(cls, context):
if cfg.CONF.cloud_backend == _default_backend:
return OpenStackClients(context)
else:
try:
return importutils.import_object(cfg.CONF.cloud_backend,
context)
except (ImportError, RuntimeError, cfg.NoSuchOptError) as err:
msg = _('Invalid cloud_backend setting in heat.conf '
'detected - %s') % six.text_type(err)
LOG.error(msg)
raise exception.Invalid(reason=msg)
Clients = ClientBackend
_mgr = None
def has_client(name):
return _mgr and name in _mgr.names()
def initialise():
global _mgr
if _mgr:
return
def client_is_available(client_plugin):
if not hasattr(client_plugin.plugin, 'is_available'):
# if the client does not have a is_available() class method, then
# we assume it wants to be always available
return True
# let the client plugin decide if it wants to register or not
return client_plugin.plugin.is_available()
_mgr = enabled.EnabledExtensionManager(
namespace='heat.clients',
check_func=client_is_available,
invoke_on_load=False)
def list_opts():
yield None, cloud_opts