Source code for ceilometer.declarative

# 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
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# Unless required by applicable law or agreed to in writing, software
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import os

from jsonpath_rw_ext import parser
from oslo_config import cfg
from oslo_log import log
import six
import yaml

from ceilometer.i18n import _, _LI

LOG = log.getLogger(__name__)

[docs]class DefinitionException(Exception): def __init__(self, message, definition_cfg): super(DefinitionException, self).__init__(message) self.definition_cfg = definition_cfg
[docs]class Definition(object): JSONPATH_RW_PARSER = parser.ExtentedJsonPathParser() GETTERS_CACHE = {} def __init__(self, name, cfg, plugin_manager): self.cfg = cfg = name self.plugin = None if isinstance(cfg, dict): if 'fields' not in cfg: raise DefinitionException( _("The field 'fields' is required for %s") % name, self.cfg) if 'plugin' in cfg: plugin_cfg = cfg['plugin'] if isinstance(plugin_cfg, six.string_types): plugin_name = plugin_cfg plugin_params = {} else: try: plugin_name = plugin_cfg['name'] except KeyError: raise DefinitionException( _('Plugin specified, but no plugin name supplied ' 'for %s') % name, self.cfg) plugin_params = plugin_cfg.get('parameters') if plugin_params is None: plugin_params = {} try: plugin_ext = plugin_manager[plugin_name] except KeyError: raise DefinitionException( _('No plugin named %(plugin)s available for ' '%(name)s') % dict( plugin=plugin_name, name=name), self.cfg) plugin_class = plugin_ext.plugin self.plugin = plugin_class(**plugin_params) fields = cfg['fields'] else: # Simple definition "foobar: jsonpath" fields = cfg if isinstance(fields, list): # NOTE(mdragon): if not a string, we assume a list. if len(fields) == 1: fields = fields[0] else: fields = '|'.join('(%s)' % path for path in fields) if isinstance(fields, six.integer_types): self.getter = fields else: try: self.getter = self.make_getter(fields) except Exception as e: raise DefinitionException( _("Parse error in JSONPath specification " "'%(jsonpath)s' for %(name)s: %(err)s") % dict(jsonpath=fields, name=name, err=e), self.cfg) def _get_path(self, match): if match.context is not None: for path_element in self._get_path(match.context): yield path_element yield str(match.path)
[docs] def parse(self, obj, return_all_values=False): if callable(self.getter): values = self.getter(obj) else: return self.getter values = [match for match in values if return_all_values or match.value is not None] if self.plugin is not None: if return_all_values and not self.plugin.support_return_all_values: raise DefinitionException("Plugin %s don't allows to " "return multiple values" % self.cfg["plugin"]["name"], self.cfg) values_map = [('.'.join(self._get_path(match)), match.value) for match in values] values = [v for v in self.plugin.trait_values(values_map) if v is not None] else: values = [match.value for match in values if match is not None] if return_all_values: return values else: return values[0] if values else None
[docs] def make_getter(self, fields): if fields in self.GETTERS_CACHE: return self.GETTERS_CACHE[fields] else: getter = self.JSONPATH_RW_PARSER.parse(fields).find self.GETTERS_CACHE[fields] = getter return getter
def load_definitions(defaults, config_file, fallback_file=None): """Setup a definitions from yaml config file.""" if not os.path.exists(config_file): config_file = cfg.CONF.find_file(config_file) if not config_file and fallback_file is not None: LOG.debug("No Definitions configuration file found!" "Using default config.") config_file = fallback_file if config_file is not None: LOG.debug("Loading definitions configuration file: %s", config_file) with open(config_file) as cf: config = try: definition_cfg = yaml.safe_load(config) except yaml.YAMLError as err: if hasattr(err, 'problem_mark'): mark = err.problem_mark errmsg = (_("Invalid YAML syntax in Definitions file " "%(file)s at line: %(line)s, column: %(column)s.") % dict(file=config_file, line=mark.line + 1, column=mark.column + 1)) else: errmsg = (_("YAML error reading Definitions file " "%(file)s") % dict(file=config_file)) LOG.error(errmsg) raise else: LOG.debug("No Definitions configuration file found!" "Using default config.") definition_cfg = defaults"Definitions: %s"), definition_cfg) return definition_cfg

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