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# to you under the Apache License, Version 2.0 (the
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#
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# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
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# KIND, either express or implied. See the License for the
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# under the License.
import re
import sys
import time
from collections import deque
from datetime import datetime, timedelta
from logging import Logger
from threading import Event, Thread
from typing import Dict, Generator, Optional
from botocore.exceptions import ClientError
from botocore.waiter import Waiter
from airflow.exceptions import AirflowException
from airflow.models import BaseOperator, XCom
from airflow.providers.amazon.aws.exceptions import ECSOperatorError
from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
from airflow.providers.amazon.aws.hooks.logs import AwsLogsHook
from airflow.typing_compat import Protocol, runtime_checkable
from airflow.utils.session import provide_session
[docs]def should_retry(exception: Exception):
"""Check if exception is related to ECS resource quota (CPU, MEM)."""
if isinstance(exception, ECSOperatorError):
return any(
quota_reason in failure['reason']
for quota_reason in ['RESOURCE:MEMORY', 'RESOURCE:CPU']
for failure in exception.failures
)
return False
[docs]@runtime_checkable
class ECSProtocol(Protocol):
"""
A structured Protocol for ``boto3.client('ecs')``. This is used for type hints on
:py:meth:`.ECSOperator.client`.
.. seealso::
- https://mypy.readthedocs.io/en/latest/protocols.html
- https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ecs.html
"""
[docs] def run_task(self, **kwargs) -> Dict:
"""https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ecs.html#ECS.Client.run_task""" # noqa: E501
...
[docs] def get_waiter(self, x: str) -> Waiter:
"""https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ecs.html#ECS.Client.get_waiter""" # noqa: E501
...
[docs] def describe_tasks(self, cluster: str, tasks) -> Dict:
"""https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ecs.html#ECS.Client.describe_tasks""" # noqa: E501
...
[docs] def stop_task(self, cluster, task, reason: str) -> Dict:
"""https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ecs.html#ECS.Client.stop_task""" # noqa: E501
...
[docs] def describe_task_definition(self, taskDefinition: str) -> Dict:
"""https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ecs.html#ECS.Client.describe_task_definition""" # noqa: E501
...
[docs] def list_tasks(self, cluster: str, launchType: str, desiredStatus: str, family: str) -> Dict:
"""https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ecs.html#ECS.Client.list_tasks""" # noqa: E501
...
[docs]class ECSTaskLogFetcher(Thread):
"""
Fetches Cloudwatch log events with specific interval as a thread
and sends the log events to the info channel of the provided logger.
"""
def __init__(
self,
*,
aws_conn_id: Optional[str] = 'aws_default',
region_name: Optional[str] = None,
log_group: str,
log_stream_name: str,
fetch_interval: timedelta,
logger: Logger,
):
super().__init__()
self._event = Event()
self.fetch_interval = fetch_interval
self.logger = logger
self.log_group = log_group
self.log_stream_name = log_stream_name
self.hook = AwsLogsHook(aws_conn_id=aws_conn_id, region_name=region_name)
[docs] def run(self) -> None:
logs_to_skip = 0
while not self.is_stopped():
log_events = self._get_log_events(logs_to_skip)
for log_event in log_events:
self.logger.info(self._event_to_str(log_event))
logs_to_skip += 1
time.sleep(self.fetch_interval.total_seconds())
def _get_log_events(self, skip: int = 0) -> Generator:
try:
yield from self.hook.get_log_events(self.log_group, self.log_stream_name, skip=skip)
except ClientError as error:
if error.response['Error']['Code'] != 'ResourceNotFoundException':
self.logger.warning('Error on retrieving Cloudwatch log events', error)
yield from ()
def _event_to_str(self, event: dict) -> str:
event_dt = datetime.utcfromtimestamp(event['timestamp'] / 1000.0)
formatted_event_dt = event_dt.strftime('%Y-%m-%d %H:%M:%S,%f')[:-3]
message = event['message']
return f'[{formatted_event_dt}] {message}'
[docs] def get_last_log_messages(self, number_messages) -> list:
return [log['message'] for log in deque(self._get_log_events(), maxlen=number_messages)]
[docs] def get_last_log_message(self) -> Optional[str]:
try:
return self.get_last_log_messages(1)[0]
except IndexError:
return None
[docs] def is_stopped(self) -> bool:
return self._event.is_set()
[docs] def stop(self):
self._event.set()
[docs]class ECSOperator(BaseOperator):
"""
Execute a task on AWS ECS (Elastic Container Service)
.. seealso::
For more information on how to use this operator, take a look at the guide:
:ref:`howto/operator:ECSOperator`
:param task_definition: the task definition name on Elastic Container Service
:type task_definition: str
:param cluster: the cluster name on Elastic Container Service
:type cluster: str
:param overrides: the same parameter that boto3 will receive (templated):
https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ecs.html#ECS.Client.run_task
:type overrides: dict
:param aws_conn_id: connection id of AWS credentials / region name. If None,
credential boto3 strategy will be used
(http://boto3.readthedocs.io/en/latest/guide/configuration.html).
:type aws_conn_id: str
:param region_name: region name to use in AWS Hook.
Override the region_name in connection (if provided)
:type region_name: str
:param launch_type: the launch type on which to run your task ('EC2' or 'FARGATE')
:type launch_type: str
:param capacity_provider_strategy: the capacity provider strategy to use for the task.
When capacity_provider_strategy is specified, the launch_type parameter is omitted.
If no capacity_provider_strategy or launch_type is specified,
the default capacity provider strategy for the cluster is used.
:type capacity_provider_strategy: list
:param group: the name of the task group associated with the task
:type group: str
:param placement_constraints: an array of placement constraint objects to use for
the task
:type placement_constraints: list
:param placement_strategy: an array of placement strategy objects to use for
the task
:type placement_strategy: list
:param platform_version: the platform version on which your task is running
:type platform_version: str
:param network_configuration: the network configuration for the task
:type network_configuration: dict
:param tags: a dictionary of tags in the form of {'tagKey': 'tagValue'}.
:type tags: dict
:param awslogs_group: the CloudWatch group where your ECS container logs are stored.
Only required if you want logs to be shown in the Airflow UI after your job has
finished.
:type awslogs_group: str
:param awslogs_region: the region in which your CloudWatch logs are stored.
If None, this is the same as the `region_name` parameter. If that is also None,
this is the default AWS region based on your connection settings.
:type awslogs_region: str
:param awslogs_stream_prefix: the stream prefix that is used for the CloudWatch logs.
This is usually based on some custom name combined with the name of the container.
Only required if you want logs to be shown in the Airflow UI after your job has
finished.
:type awslogs_stream_prefix: str
:param awslogs_fetch_interval: the interval that the ECS task log fetcher should wait
in between each Cloudwatch logs fetches.
:type awslogs_fetch_interval: timedelta
:param quota_retry: Config if and how to retry the launch of a new ECS task, to handle
transient errors.
:type quota_retry: dict
:param reattach: If set to True, will check if the task previously launched by the task_instance
is already running. If so, the operator will attach to it instead of starting a new task.
This is to avoid relaunching a new task when the connection drops between Airflow and ECS while
the task is running (when the Airflow worker is restarted for example).
:type reattach: bool
:param number_logs_exception: Number of lines from the last Cloudwatch logs to return in the
AirflowException if an ECS task is stopped (to receive Airflow alerts with the logs of what
failed in the code running in ECS).
:type number_logs_exception: int
"""
[docs] template_fields = ('overrides',)
[docs] template_fields_renderers = {
"overrides": "json",
"network_configuration": "json",
"tags": "json",
"quota_retry": "json",
}
[docs] REATTACH_XCOM_KEY = "ecs_task_arn"
[docs] REATTACH_XCOM_TASK_ID_TEMPLATE = "{task_id}_task_arn"
def __init__(
self,
*,
task_definition: str,
cluster: str,
overrides: dict,
aws_conn_id: Optional[str] = None,
region_name: Optional[str] = None,
launch_type: str = 'EC2',
capacity_provider_strategy: Optional[list] = None,
group: Optional[str] = None,
placement_constraints: Optional[list] = None,
placement_strategy: Optional[list] = None,
platform_version: Optional[str] = None,
network_configuration: Optional[dict] = None,
tags: Optional[dict] = None,
awslogs_group: Optional[str] = None,
awslogs_region: Optional[str] = None,
awslogs_stream_prefix: Optional[str] = None,
awslogs_fetch_interval: timedelta = timedelta(seconds=30),
propagate_tags: Optional[str] = None,
quota_retry: Optional[dict] = None,
reattach: bool = False,
number_logs_exception: int = 10,
**kwargs,
):
super().__init__(**kwargs)
self.aws_conn_id = aws_conn_id
self.region_name = region_name
self.task_definition = task_definition
self.cluster = cluster
self.overrides = overrides
self.launch_type = launch_type
self.capacity_provider_strategy = capacity_provider_strategy
self.group = group
self.placement_constraints = placement_constraints
self.placement_strategy = placement_strategy
self.platform_version = platform_version
self.network_configuration = network_configuration
self.tags = tags
self.awslogs_group = awslogs_group
self.awslogs_stream_prefix = awslogs_stream_prefix
self.awslogs_region = awslogs_region
self.awslogs_fetch_interval = awslogs_fetch_interval
self.propagate_tags = propagate_tags
self.reattach = reattach
self.number_logs_exception = number_logs_exception
if self.awslogs_region is None:
self.awslogs_region = region_name
self.hook: Optional[AwsBaseHook] = None
self.client: Optional[ECSProtocol] = None
self.arn: Optional[str] = None
self.retry_args = quota_retry
self.task_log_fetcher: Optional[ECSTaskLogFetcher] = None
@provide_session
[docs] def execute(self, context, session=None):
self.log.info(
'Running ECS Task - Task definition: %s - on cluster %s', self.task_definition, self.cluster
)
self.log.info('ECSOperator overrides: %s', self.overrides)
self.client = self.get_hook().get_conn()
if self.reattach:
self._try_reattach_task(context)
if not self.arn:
self._start_task(context)
if self._aws_logs_enabled():
self.log.info('Starting ECS Task Log Fetcher')
self.task_log_fetcher = self._get_task_log_fetcher()
self.task_log_fetcher.start()
try:
self._wait_for_task_ended()
finally:
self.task_log_fetcher.stop()
self.task_log_fetcher.join()
else:
self._wait_for_task_ended()
self._check_success_task()
self.log.info('ECS Task has been successfully executed')
if self.reattach:
# Clear the XCom value storing the ECS task ARN if the task has completed
# as we can't reattach it anymore
self._xcom_del(session, self.REATTACH_XCOM_TASK_ID_TEMPLATE.format(task_id=self.task_id))
if self.do_xcom_push and self.task_log_fetcher:
return self.task_log_fetcher.get_last_log_message()
return None
def _xcom_del(self, session, task_id):
session.query(XCom).filter(XCom.dag_id == self.dag_id, XCom.task_id == task_id).delete()
def _start_task(self, context):
run_opts = {
'cluster': self.cluster,
'taskDefinition': self.task_definition,
'overrides': self.overrides,
'startedBy': self.owner,
}
if self.capacity_provider_strategy:
run_opts['capacityProviderStrategy'] = self.capacity_provider_strategy
elif self.launch_type:
run_opts['launchType'] = self.launch_type
if self.platform_version is not None:
run_opts['platformVersion'] = self.platform_version
if self.group is not None:
run_opts['group'] = self.group
if self.placement_constraints is not None:
run_opts['placementConstraints'] = self.placement_constraints
if self.placement_strategy is not None:
run_opts['placementStrategy'] = self.placement_strategy
if self.network_configuration is not None:
run_opts['networkConfiguration'] = self.network_configuration
if self.tags is not None:
run_opts['tags'] = [{'key': k, 'value': v} for (k, v) in self.tags.items()]
if self.propagate_tags is not None:
run_opts['propagateTags'] = self.propagate_tags
response = self.client.run_task(**run_opts)
failures = response['failures']
if len(failures) > 0:
raise ECSOperatorError(failures, response)
self.log.info('ECS Task started: %s', response)
self.arn = response['tasks'][0]['taskArn']
self.ecs_task_id = self.arn.split("/")[-1]
self.log.info(f"ECS task ID is: {self.ecs_task_id}")
if self.reattach:
# Save the task ARN in XCom to be able to reattach it if needed
self._xcom_set(
context,
key=self.REATTACH_XCOM_KEY,
value=self.arn,
task_id=self.REATTACH_XCOM_TASK_ID_TEMPLATE.format(task_id=self.task_id),
)
def _xcom_set(self, context, key, value, task_id):
XCom.set(
key=key,
value=value,
task_id=task_id,
dag_id=self.dag_id,
execution_date=context["ti"].execution_date,
)
def _try_reattach_task(self, context):
task_def_resp = self.client.describe_task_definition(taskDefinition=self.task_definition)
ecs_task_family = task_def_resp['taskDefinition']['family']
list_tasks_resp = self.client.list_tasks(
cluster=self.cluster, desiredStatus='RUNNING', family=ecs_task_family
)
running_tasks = list_tasks_resp['taskArns']
# Check if the ECS task previously launched is already running
previous_task_arn = self.xcom_pull(
context,
task_ids=self.REATTACH_XCOM_TASK_ID_TEMPLATE.format(task_id=self.task_id),
key=self.REATTACH_XCOM_KEY,
)
if previous_task_arn in running_tasks:
self.arn = previous_task_arn
self.log.info("Reattaching previously launched task: %s", self.arn)
else:
self.log.info("No active previously launched task found to reattach")
def _wait_for_task_ended(self) -> None:
if not self.client or not self.arn:
return
waiter = self.client.get_waiter('tasks_stopped')
waiter.config.max_attempts = sys.maxsize # timeout is managed by airflow
waiter.wait(cluster=self.cluster, tasks=[self.arn])
return
def _aws_logs_enabled(self):
return self.awslogs_group and self.awslogs_stream_prefix
def _get_task_log_fetcher(self) -> ECSTaskLogFetcher:
log_stream_name = f"{self.awslogs_stream_prefix}/{self.ecs_task_id}"
return ECSTaskLogFetcher(
aws_conn_id=self.aws_conn_id,
region_name=self.awslogs_region,
log_group=self.awslogs_group,
log_stream_name=log_stream_name,
fetch_interval=self.awslogs_fetch_interval,
logger=self.log,
)
def _check_success_task(self) -> None:
if not self.client or not self.arn:
return
response = self.client.describe_tasks(cluster=self.cluster, tasks=[self.arn])
self.log.info('ECS Task stopped, check status: %s', response)
if len(response.get('failures', [])) > 0:
raise AirflowException(response)
for task in response['tasks']:
if task.get('stopCode', '') == 'TaskFailedToStart':
raise AirflowException(f"The task failed to start due to: {task.get('stoppedReason', '')}")
# This is a `stoppedReason` that indicates a task has not
# successfully finished, but there is no other indication of failure
# in the response.
# https://docs.aws.amazon.com/AmazonECS/latest/developerguide/stopped-task-errors.html
if re.match(r'Host EC2 \(instance .+?\) (stopped|terminated)\.', task.get('stoppedReason', '')):
raise AirflowException(
'The task was stopped because the host instance terminated: {}'.format(
task.get('stoppedReason', '')
)
)
containers = task['containers']
for container in containers:
if container.get('lastStatus') == 'STOPPED' and container['exitCode'] != 0:
if self.task_log_fetcher:
last_logs = "\n".join(
self.task_log_fetcher.get_last_log_messages(self.number_logs_exception)
)
raise AirflowException(
f"This task is not in success state - last {self.number_logs_exception} "
f"logs from Cloudwatch:\n{last_logs}"
)
else:
raise AirflowException(f'This task is not in success state {task}')
elif container.get('lastStatus') == 'PENDING':
raise AirflowException(f'This task is still pending {task}')
elif 'error' in container.get('reason', '').lower():
raise AirflowException(
'This containers encounter an error during launching : {}'.format(
container.get('reason', '').lower()
)
)
[docs] def get_hook(self) -> AwsBaseHook:
"""Create and return an AwsHook."""
if self.hook:
return self.hook
self.hook = AwsBaseHook(aws_conn_id=self.aws_conn_id, client_type='ecs', region_name=self.region_name)
return self.hook
[docs] def on_kill(self) -> None:
if not self.client or not self.arn:
return
if self.task_log_fetcher:
self.task_log_fetcher.stop()
response = self.client.stop_task(
cluster=self.cluster, task=self.arn, reason='Task killed by the user'
)
self.log.info(response)