def run(self, event):
"""Run the alert processor!
Args:
event (dict): Lambda invocation event containing at least the rule name and alert ID.
Returns:
dict: Maps output (str) to whether it sent successfully (bool).
An empty dict is returned if the Alert was improperly formatted.
"""
# Grab the alert record from Dynamo (if needed).
if set(event) == {'AlertID', 'RuleName'}:
LOGGER.info('Retrieving %s from alerts table', event)
alert_record = self.alerts_table.get_alert_record(event['RuleName'], event['AlertID'])
if not alert_record:
LOGGER.error('%s does not exist in the alerts table', event)
return {}
else:
alert_record = event
# Convert record to an Alert instance.
try:
alert = Alert.create_from_dynamo_record(alert_record)
except AlertCreationError:
LOGGER.exception('Invalid alert %s', event)
return {}
# Remove normalization key from the record.
# TODO: Consider including this in at least some outputs, e.g. default Athena firehose
if NORMALIZATION_KEY in alert.record:
del alert.record[NORMALIZATION_KEY]
result = self._send_to_outputs(alert)
self._update_table(alert, result)
return result
def _dispatch(self, alert, descriptor):
"""Send alert to Cloudwatch Logger for Lambda
Args:
alert (Alert): Alert instance which triggered a rule
descriptor (str): Output descriptor
"""
LOGGER.info('New Alert:\n%s', json.dumps(alert.output_dict(),
indent=4))
return True
def dispatch(self, **kwargs):
"""Send alert to a Kinesis Firehose Delivery Stream
Keyword Args:
descriptor (str): Service descriptor (ie: slack channel, pd integration)
rule_name (str): Name of the triggered rule
alert (dict): Alert relevant to the triggered rule
Returns:
bool: Indicates a successful or failed dispatch of the alert
"""
@backoff.on_exception(backoff.fibo,
ClientError,
max_tries=self.MAX_BACKOFF_ATTEMPTS,
jitter=backoff.full_jitter,
on_backoff=backoff_handler,
on_success=success_handler,
on_giveup=giveup_handler)
def _firehose_request_wrapper(json_alert, delivery_stream):
"""Make the PutRecord request to Kinesis Firehose with backoff
Args:
json_alert (str): The JSON dumped alert body
delivery_stream (str): The Firehose Delivery Stream to send to
Returns:
dict: Firehose response in the format below
{'RecordId': 'string'}
"""
return self.__aws_client__.put_record(
DeliveryStreamName=delivery_stream,
Record={'Data': json_alert})
if self.__aws_client__ is None:
self.__aws_client__ = boto3.client('firehose',
region_name=self.region)
json_alert = json.dumps(kwargs['alert'], separators=(',', ':')) + '\n'
if len(json_alert) > self.MAX_RECORD_SIZE:
LOGGER.error('Alert too large to send to Firehose: \n%s...',
json_alert[0:1000])
return False
delivery_stream = self.config[self.__service__][kwargs['descriptor']]
LOGGER.info('Sending alert [%s] to aws-firehose:%s',
kwargs['rule_name'], delivery_stream)
resp = _firehose_request_wrapper(json_alert, delivery_stream)
if resp.get('RecordId'):
LOGGER.info(
'Alert [%s] successfully sent to aws-firehose:%s with RecordId:%s',
kwargs['rule_name'], delivery_stream, resp['RecordId'])
return self._log_status(resp, kwargs['descriptor'])
def _log_status(cls, success):
"""Log the status of sending the alerts
Args:
success (bool or dict): Indicates if the dispatching of alerts was successful
"""
if success:
LOGGER.info('Successfully sent alert to %s', cls.__service__)
else:
LOGGER.error('Failed to send alert to %s', cls.__service__)
return bool(success)
def _log_status(cls, success, descriptor):
"""Log the status of sending the alerts
Args:
success (bool or dict): Indicates if the dispatching of alerts was successful
descriptor (str): Service descriptor
"""
if success:
LOGGER.info('Successfully sent alert to %s:%s', cls.__service__,
descriptor)
else:
LOGGER.error('Failed to send alert to %s:%s', cls.__service__,
descriptor)
def _dispatch(self, alert, descriptor):
"""Send alert to a Kinesis Firehose Delivery Stream
Args:
alert (Alert): Alert instance which triggered a rule
descriptor (str): Output descriptor
Returns:
bool: True if alert was sent successfully, False otherwise
"""
@backoff.on_exception(backoff.fibo,
ClientError,
max_tries=self.MAX_BACKOFF_ATTEMPTS,
jitter=backoff.full_jitter,
on_backoff=backoff_handler(),
on_success=success_handler(),
on_giveup=giveup_handler())
def _firehose_request_wrapper(json_alert, delivery_stream):
"""Make the PutRecord request to Kinesis Firehose with backoff
Args:
json_alert (str): The JSON dumped alert body
delivery_stream (str): The Firehose Delivery Stream to send to
Returns:
dict: Firehose response in the format below
{'RecordId': 'string'}
"""
self.__aws_client__.put_record(DeliveryStreamName=delivery_stream,
Record={'Data': json_alert})
if self.__aws_client__ is None:
self.__aws_client__ = boto3.client('firehose',
region_name=self.region)
json_alert = json.dumps(alert.output_dict(),
separators=(',', ':')) + '\n'
if len(json_alert) > self.MAX_RECORD_SIZE:
LOGGER.error('Alert too large to send to Firehose: \n%s...',
json_alert[0:1000])
return False
delivery_stream = self.config[self.__service__][descriptor]
LOGGER.info('Sending %s to aws-firehose:%s', alert, delivery_stream)
_firehose_request_wrapper(json_alert, delivery_stream)
LOGGER.info('%s successfully sent to aws-firehose:%s', alert,
delivery_stream)
return True
def _send_alert(alert_payload, output, dispatcher):
"""Send a single alert to the given output.
Returns:
bool: True if the alert was sent successfully.
"""
LOGGER.info('Sending alert %s to %s', alert_payload['id'], output)
try:
return dispatcher.dispatch(descriptor=output.split(':')[1],
rule_name=alert_payload['rule_name'],
alert=alert_payload)
except Exception: # pylint: disable=broad-except
LOGGER.exception(
'Exception when sending alert %s to %s. Alert:\n%s',
alert_payload['id'], output, json.dumps(alert_payload,
indent=2))
return False
def _send_alert(alert, output, dispatcher):
"""Send a single alert to the given output.
Args:
alert (Alert): Alert to be sent
output (str): Alert output, e.g. "aws-sns:topic-name"
dispatcher (OutputDispatcher): Dispatcher to receive the alert
Returns:
bool: True if the alert was sent successfully.
"""
LOGGER.info('Sending %s to %s', alert, output)
try:
return dispatcher.dispatch(alert, output.split(':')[1])
except Exception: # pylint: disable=broad-except
LOGGER.exception('Exception when sending %s to %s. Alert:\n%s',
alert, output, repr(alert))
return False
def _item_verify(self, item_str, item_key, item_type, get_id=True):
"""Method to verify the existance of an item with the API
Args:
item_str (str): Service to query about in the API
item_key (str): Endpoint/key to be extracted from search results
item_type (str): Type of item reference to be returned
get_id (boolean): Whether to generate a dict with result and reference
Returns:
dict: JSON object be used in the API call, containing the item id
and the item reference, True if it just exists or False if it fails
"""
item_url = self._get_endpoint(self._base_url, item_key)
item_id = self._check_exists(item_str, item_url, item_key, get_id)
if not item_id:
LOGGER.info('%s not found in %s, %s', item_str, item_key, self.__service__)
return False
if get_id:
return {'id': item_id, 'type': item_type}
return item_id
def dispatch(self, alert, output):
"""Send alerts to the given service.
This wraps the protected subclass method of _dispatch to aid in usability
Args:
alert (Alert): Alert instance which triggered a rule
descriptor (str): Output descriptor (e.g. slack channel, pd integration)
Returns:
bool: True if alert was sent successfully, False otherwise
"""
LOGGER.info('Sending %s to %s', alert, output)
descriptor = output.split(':')[1]
try:
sent = bool(self._dispatch(alert, descriptor))
except Exception: # pylint: disable=broad-except
LOGGER.exception('Exception when sending %s to %s. Alert:\n%s',
alert, output, repr(alert))
sent = False
self._log_status(sent, descriptor)
return sent
