Ceilometer/blueprints/alarm-api

原始

AlarmController

class AlarmController(rest.RestController):
    """Manages operations on a single alarm.
    """

    @wsme_pecan.wsexpose(Alarm, wtypes.text)
    def get(self):
        """Return this alarm."""

    @wsme.validate(Alarm)
    @wsme_pecan.wsexpose(Alarm, wtypes.text, body=Alarm)
    def put(self, data):
        """Modify this alarm."""

    @wsme_pecan.wsexpose(None, wtypes.text, status_code=204)
    def delete(self):
        """Delete this alarm."""

    # TODO(eglynn): add pagination marker to signature once overall
    #               API support for pagination is finalized
    @wsme_pecan.wsexpose([AlarmChange], [Query])
    def history(self, q=[]):
        """Assembles the alarm history requested.

        :param q: Filter rules for the changes to be described.
        """

AlarmsController

class AlarmsController(rest.RestController):
    """Manages operations on the alarms collection.
    """

    @wsme.validate(Alarm)
    @wsme_pecan.wsexpose(Alarm, body=Alarm, status_code=201)
    def post(self, data):
        """Create a new alarm."""

    @wsme_pecan.wsexpose([Alarm], [Query])
    def get_all(self, q=[]):
        """Return all alarms, based on the query provided.

        :param q: Filter rules for the alarms to be returned.
        """

Alarm 类

class Alarm(_Base):
    """Representation of an alarm.
    """

    alarm_id = wtypes.text
    "The UUID of the alarm"

    name = wtypes.text
    "The name for the alarm"

    description = wtypes.text
    "The description of the alarm"

    meter_name = wtypes.text
    "The name of meter"

    project_id = wtypes.text
    "The ID of the project or tenant that owns the alarm"

    user_id = wtypes.text
    "The ID of the user who created the alarm"

    comparison_operator = wtypes.Enum(str, 'lt', 'le', 'eq', 'ne', 'ge', 'gt')
    "The comparison against the alarm threshold"

    threshold = float
    "The threshold of the alarm"

    statistic = wtypes.Enum(str, 'max', 'min', 'avg', 'sum', 'count')
    "The statistic to compare to the threshold"

    enabled = bool
    "This alarm is enabled?"

    evaluation_periods = int
    "The number of periods to evaluate the threshold"

    period = int
    "The time range in seconds over which to evaluate the threshold"

    timestamp = datetime.datetime
    "The date of the last alarm definition update"

    state = wtypes.Enum(str, 'ok', 'alarm', 'insufficient data')
    "The state offset the alarm"

    state_timestamp = datetime.datetime
    "The date of the last alarm state changed"

    ok_actions = [wtypes.text]
    "The actions to do when alarm state change to ok"

    alarm_actions = [wtypes.text]
    "The actions to do when alarm state change to alarm"

    insufficient_data_actions = [wtypes.text]
    "The actions to do when alarm state change to insufficient data"

    repeat_actions = bool
    "The actions should be re-triggered on each evaluation cycle"

    matching_metadata = {wtypes.text: wtypes.text}
    "The matching_metadata of the alarm"

更新

Alarm 状态枚举

这个枚举在多个地方被重用。

AlarmState = wtypes.Enum(wtypes.text, 'ok', 'alarm', 'insufficient_data')

AlarmThresholdRule

收集用于定义基于统计值达到阈值的规则的参数。

class AlarmThresholdRule(_Base):

    query = [Query]
    "The query to find the data for computing statistics, including meter_name. Ownership settings are automatically included based on the Alarm owner."

    period = int
    "The time range in seconds over which query"

    comparison_operator = wtypes.Enum(str, 'lt', 'le', 'eq', 'ne', 'ge', 'gt')
    "The comparison against the alarm threshold"

    threshold = float
    "The threshold of the alarm"

    statistic = wtypes.Enum(str, 'max', 'min', 'avg', 'sum', 'count')
    "The statistic to compare to the threshold"

    evaluation_periods = int
    "The number of historical periods to evaluate the threshold"

AlarmCombinationRule

收集与组合多个警报相关的设置。

class AlarmCombinationRule(_Base):

    operator = wtypes.Enum(str, 'or', 'and')
    "How to combine the sub-alarms"

   alarm_ids = [wtypes.text]
   "List of alarm identifiers to combine"

Alarm

父数据结构。

class Alarm(_Base):
    """Representation of an alarm.
    """

    alarm_id = wtypes.text
    "The UUID of the alarm"

    name = wtypes.text
    "The name for the alarm"

    description = wtypes.text
    "The description of the alarm"

    enabled = bool
    "This alarm is enabled?"

    ok_actions = [wtypes.text]
    "The actions to do when alarm state change to ok"

    alarm_actions = [wtypes.text]
    "The actions to do when alarm state change to alarm"

    insufficient_data_actions = [wtypes.text]
    "The actions to do when alarm state change to insufficient data"

    repeat_actions = bool
    "The actions should be re-triggered on each evaluation cycle"

    type = Enum(str, 'threshold', 'combination')
    "Explicit type specifier to select which rule to follow below."

    threshold_rule = AlarmThresholdRule
    "Describe when to trigger the alarm based on computed statistics"

    combination_rule = AlarmCombinationRule
    "Describe when to trigger the alarm based on combining the settings of other alarms"

    # These settings are ignored in the the PUT or POST operations, but are filled in for GET

    project_id = wtypes.text
    "The ID of the project or tenant that owns the alarm"

    user_id = wtypes.text
    "The ID of the user who created the alarm"

    timestamp = datetime.datetime
    "The date of the last alarm definition update"

    # FIXME: Add an explicit "set_state" operation instead of 
    # forcing the caller to PUT the entire definition of the alarm to test it.
    state = alarm_states
    "The current state of the alarm"

    state_timestamp = datetime.datetime
    "The date of the last alarm state changed"

被拒绝的方案

这些选项被考虑过但被拒绝了。

统一规则规范

不幸的是，这两种规则类型之间没有太多共同之处。规则规范的另一种格式是将设置编码为参数列表，但这并不能帮助调用者了解何时需要哪些参数。

class Rule(_Base):

  type = wtypes.Enum(str, 'threshold', 'combination')

  operator = wtypes.Enum(str, 'lt', 'le', 'eq', 'ne', 'ge', 'gt', 'in')

  arguments = [wtypes.text]

DSL

如果我们想变得更加复杂，我们应该考虑创建一个特定领域语言，并用包含该 DSL 的文本块来描述警报规则。我们可以记录 DSL，它不需要复杂的语法。例如，它可以是面向行的，使用空格分隔表达式等。

query field1 >= blah field2 == value
threshold min > 0 or max < 100

combination alarm1 and alarm2

AlarmAction 类

将所有操作统一到一个具有状态和 URL 的类中，而不是保留 3 个单独的列表。

class AlarmAction(_Base):
   """Action to take when alarm changes state.
   """

  state = AlarmState
  "The state for which the action applies."

  url = wtypes.text
  "The URL to visit when the alarm state is reached"