Source code for airflow.providers.amazon.aws.sensors.emr_base
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from typing import Any, Dict, Iterable, Optional
from airflow.exceptions import AirflowException
from airflow.providers.amazon.aws.hooks.emr import EmrHook
from airflow.sensors.base import BaseSensorOperator
from airflow.utils.decorators import apply_defaults
[docs]class EmrBaseSensor(BaseSensorOperator):
"""
Contains general sensor behavior for EMR.
Subclasses should implement following methods:
- ``get_emr_response()``
- ``state_from_response()``
- ``failure_message_from_response()``
Subclasses should set ``target_states`` and ``failed_states`` fields.
:param aws_conn_id: aws connection to uses
:type aws_conn_id: str
"""
@apply_defaults
def __init__(self, *, aws_conn_id: str = 'aws_default', **kwargs):
super().__init__(**kwargs)
self.aws_conn_id = aws_conn_id
self.target_states: Optional[Iterable[str]] = None # will be set in subclasses
self.failed_states: Optional[Iterable[str]] = None # will be set in subclasses
self.hook: Optional[EmrHook] = None
[docs] def get_hook(self) -> EmrHook:
"""Get EmrHook"""
if self.hook:
return self.hook
self.hook = EmrHook(aws_conn_id=self.aws_conn_id)
return self.hook
[docs] def poke(self, context):
response = self.get_emr_response()
if not response['ResponseMetadata']['HTTPStatusCode'] == 200:
self.log.info('Bad HTTP response: %s', response)
return False
state = self.state_from_response(response)
self.log.info('Job flow currently %s', state)
if state in self.target_states:
return True
if state in self.failed_states:
final_message = 'EMR job failed'
failure_message = self.failure_message_from_response(response)
if failure_message:
final_message += ' ' + failure_message
raise AirflowException(final_message)
return False
[docs] def get_emr_response(self) -> Dict[str, Any]:
"""
Make an API call with boto3 and get response.
:return: response
:rtype: dict[str, Any]
"""
raise NotImplementedError('Please implement get_emr_response() in subclass')
@staticmethod
[docs] def state_from_response(response: Dict[str, Any]) -> str:
"""
Get state from response dictionary.
:param response: response from AWS API
:type response: dict[str, Any]
:return: state
:rtype: str
"""
raise NotImplementedError('Please implement state_from_response() in subclass')
@staticmethod
[docs] def failure_message_from_response(response: Dict[str, Any]) -> Optional[str]:
"""
Get failure message from response dictionary.
:param response: response from AWS API
:type response: dict[str, Any]
:return: failure message
:rtype: Optional[str]
"""
raise NotImplementedError('Please implement failure_message_from_response() in subclass')