ceilometer.event.trait_plugins

Source code for ceilometer.event.trait_plugins

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# Copyright 2013 Rackspace Hosting.
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#      http://www.apache.org/licenses/LICENSE-2.0
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import abc

from debtcollector import moves
from oslo_log import log
from oslo_utils import timeutils
import six

LOG = log.getLogger(__name__)


[docs]@six.add_metaclass(abc.ABCMeta) class TraitPluginBase(object): """Base class for plugins. It converts notification fields to Trait values. """ support_return_all_values = False """If True, an exception will be raised if the user expect the plugin to return one trait per match_list, but the plugin doesn't allow/support that. """ def __init__(self, **kw): """Setup the trait plugin. For each Trait definition a plugin is used on in a conversion definition, a new instance of the plugin will be created, and initialized with the parameters (if any) specified in the config file. :param kw: the parameters specified in the event definitions file. """ super(TraitPluginBase, self).__init__()
[docs] @moves.moved_method('trait_values', version=6.0, removal_version="?") def trait_value(self, match_list): pass
[docs] def trait_values(self, match_list): """Convert a set of fields to one or multiple Trait values. This method is called each time a trait is attempted to be extracted from a notification. It will be called *even if* no matching fields are found in the notification (in that case, the match_list will be empty). If this method returns None, the trait *will not* be added to the event. Any other value returned by this method will be used as the value for the trait. Values returned will be coerced to the appropriate type for the trait. :param match_list: A list (may be empty if no matches) of *tuples*. Each tuple is (field_path, value) where field_path is the jsonpath for that specific field. Example:: trait's fields definition: ['payload.foobar', 'payload.baz', 'payload.thing.*'] notification body: { 'metadata': {'message_id': '12345'}, 'publisher': 'someservice.host', 'payload': { 'foobar': 'test', 'thing': { 'bar': 12, 'boing': 13, } } } match_list will be: [('payload.foobar','test'), ('payload.thing.bar',12), ('payload.thing.boing',13)] Here is a plugin that emulates the default (no plugin) behavior: .. code-block:: python class DefaultPlugin(TraitPluginBase): "Plugin that returns the first field value." def __init__(self, **kw): super(DefaultPlugin, self).__init__() def trait_value(self, match_list): if not match_list: return None return [ match[1] for match in match_list] """ # For backwards compatibility for the renamed method. return [self.trait_value(match_list)]
[docs]class SplitterTraitPlugin(TraitPluginBase): """Plugin that splits a piece off of a string value.""" support_return_all_values = True def __init__(self, separator=".", segment=0, max_split=None, **kw): """Setup how do split the field. :param separator: String to split on. default "." :param segment: Which segment to return. (int) default 0 :param max_split: Limit number of splits. Default: None (no limit) """ LOG.warning('split plugin is deprecated, ' 'add ".`split(%(sep)s, %(segment)d, ' '%(max_split)d)`" to your jsonpath instead' % dict(sep=separator, segment=segment, max_split=(-1 if max_split is None else max_split))) self.separator = separator self.segment = segment self.max_split = max_split super(SplitterTraitPlugin, self).__init__(**kw)
[docs] def trait_values(self, match_list): return [self._trait_value(match) for match in match_list]
def _trait_value(self, match): value = six.text_type(match[1]) if self.max_split is not None: values = value.split(self.separator, self.max_split) else: values = value.split(self.separator) try: return values[self.segment] except IndexError: return None
[docs]class BitfieldTraitPlugin(TraitPluginBase): """Plugin to set flags on a bitfield.""" def __init__(self, initial_bitfield=0, flags=None, **kw): """Setup bitfield trait. :param initial_bitfield: (int) initial value for the bitfield Flags that are set will be OR'ed with this. :param flags: List of dictionaries defining bitflags to set depending on data in the notification. Each one has the following keys: path: jsonpath of field to match. bit: (int) number of bit to set (lsb is bit 0) value: set bit if corresponding field's value matches this. If value is not provided, bit will be set if the field exists (and is non-null), regardless of its value. """ self.initial_bitfield = initial_bitfield if flags is None: flags = [] self.flags = flags super(BitfieldTraitPlugin, self).__init__(**kw)
[docs] def trait_values(self, match_list): matches = dict(match_list) bitfield = self.initial_bitfield for flagdef in self.flags: path = flagdef['path'] bit = 2 ** int(flagdef['bit']) if path in matches: if 'value' in flagdef: if matches[path] == flagdef['value']: bitfield |= bit else: bitfield |= bit return [bitfield]
[docs]class TimedeltaPluginMissedFields(Exception): def __init__(self): msg = ('It is required to use two timestamp field with Timedelta ' 'plugin.') super(TimedeltaPluginMissedFields, self).__init__(msg)
[docs]class TimedeltaPlugin(TraitPluginBase): """Setup timedelta meter volume of two timestamps fields. Example:: trait's fields definition: ['payload.created_at', 'payload.launched_at'] value is been created as total seconds between 'launched_at' and 'created_at' timestamps. """ # TODO(idegtiarov): refactor code to have meter_plugins separate from # trait_plugins
[docs] def trait_value(self, match_list): if len(match_list) != 2: LOG.warning('Timedelta plugin is required two timestamp fields' ' to create timedelta value.') return start, end = match_list try: start_time = timeutils.parse_isotime(start[1]) end_time = timeutils.parse_isotime(end[1]) except Exception as err: LOG.warning('Failed to parse date from set fields, both ' 'fields %(start)s and %(end)s must be datetime: ' '%(err)s' % dict(start=start[0], end=end[0], err=err) ) return return abs((end_time - start_time).total_seconds())
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