deb-sahara/sahara/plugins/base.py
Nikolay Starodubtsev ce62f364cd Rewrite log levels and messages
This is an initial commit to make sahara logs relevant to new
logging spec.
We need to change some log levels to become closer to the spec, also
we need to change some log messages (e.g. for INFO level).

partially-implement bp new-style-logging

Change-Id: I8e7b7c4c3f375648d2999b1d0e19b68390cc22a8
2015-03-12 17:16:06 +03:00

143 lines
3.7 KiB
Python

# Copyright (c) 2013 Mirantis 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 abc
from oslo_config import cfg
from oslo_log import log as logging
import six
from stevedore import enabled
from sahara import exceptions as ex
from sahara.i18n import _
from sahara.i18n import _LI
from sahara.utils import resources
LOG = logging.getLogger(__name__)
opts = [
cfg.ListOpt('plugins',
default=['vanilla', 'hdp', 'spark', 'cdh'],
help='List of plugins to be loaded. Sahara preserves the '
'order of the list when returning it.'),
]
CONF = cfg.CONF
CONF.register_opts(opts)
def required(fun):
return abc.abstractmethod(fun)
def required_with_default(fun):
return fun
def optional(fun):
fun.__not_implemented__ = True
return fun
@six.add_metaclass(abc.ABCMeta)
class PluginInterface(resources.BaseResource):
__resource_name__ = 'plugin'
name = 'plugin_interface'
@required
def get_title(self):
"""Plugin title
For example:
"Vanilla Provisioning"
"""
pass
@required_with_default
def get_description(self):
"""Optional description of the plugin
This information is targeted to be displayed in UI.
"""
pass
def to_dict(self):
return {
'name': self.name,
'title': self.get_title(),
'description': self.get_description(),
}
class PluginManager(object):
def __init__(self):
self.plugins = {}
self._load_cluster_plugins()
def _load_cluster_plugins(self):
config_plugins = CONF.plugins
extension_manager = enabled.EnabledExtensionManager(
check_func=lambda ext: ext.name in config_plugins,
namespace='sahara.cluster.plugins',
invoke_on_load=True
)
for ext in extension_manager.extensions:
if ext.name in self.plugins:
raise ex.ConfigurationError(
_("Plugin with name '%s' already exists.") % ext.name)
ext.obj.name = ext.name
self.plugins[ext.name] = ext.obj
LOG.info(_LI("Plugin {plugin_name} loaded {entry_point}").format(
plugin_name=ext.name,
entry_point=ext.entry_point_target))
if len(self.plugins) < len(config_plugins):
loaded_plugins = set(six.iterkeys(self.plugins))
requested_plugins = set(config_plugins)
raise ex.ConfigurationError(
_("Plugins couldn't be loaded: %s") %
", ".join(requested_plugins - loaded_plugins))
def get_plugins(self, base):
return [
self.plugins[plugin] for plugin in CONF.plugins
if not base or issubclass(self.plugins[plugin].__class__, base)
]
def get_plugin(self, plugin_name):
return self.plugins.get(plugin_name)
def is_plugin_implements(self, plugin_name, fun_name):
plugin = self.get_plugin(plugin_name)
fun = getattr(plugin, fun_name)
if not (fun and callable(fun)):
return False
return not hasattr(fun, '__not_implemented__')
PLUGINS = None
def setup_plugins():
global PLUGINS
PLUGINS = PluginManager()