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#
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#
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from __future__ import annotations
from collections.abc import Iterable, Sequence
from datetime import timedelta
from typing import TYPE_CHECKING, Any
from botocore.exceptions import ClientError
from airflow.providers.amazon.aws.hooks.dynamodb import DynamoDBHook
from airflow.providers.amazon.aws.sensors.base_aws import AwsBaseSensor
from airflow.providers.amazon.aws.triggers.dynamodb import DynamoDBValueSensorTrigger
from airflow.providers.amazon.aws.utils import validate_execute_complete_event
from airflow.providers.amazon.aws.utils.mixins import aws_template_fields
from airflow.providers.common.compat.sdk import conf
if TYPE_CHECKING:
from airflow.sdk import Context
[docs]
class DynamoDBValueSensor(AwsBaseSensor[DynamoDBHook]):
"""
Waits for an attribute value to be present for an item in a DynamoDB table.
.. seealso::
For more information on how to use this sensor, take a look at the guide:
:ref:`howto/sensor:DynamoDBValueSensor`
:param table_name: DynamoDB table name
:param partition_key_name: DynamoDB partition key name
:param partition_key_value: DynamoDB partition key value
:param attribute_name: DynamoDB attribute name
:param attribute_value: DynamoDB attribute value
:param sort_key_name: (optional) DynamoDB sort key name
:param sort_key_value: (optional) DynamoDB sort key value
:param deferrable: If True, the sensor will operate in deferrable mode. This mode requires aiobotocore
module to be installed.
(default: False, but can be overridden in config file by setting default_deferrable to True)
:param aws_conn_id: The Airflow connection used for AWS credentials.
If this is ``None`` or empty then the default boto3 behaviour is used. If
running Airflow in a distributed manner and aws_conn_id is None or
empty, then default boto3 configuration would be used (and must be
maintained on each worker node).
:param region_name: AWS region_name. If not specified then the default boto3 behaviour is used.
:param verify: Whether or not to verify SSL certificates. See:
https://boto3.amazonaws.com/v1/documentation/api/latest/reference/core/session.html
:param botocore_config: Configuration dictionary (key-values) for botocore client. See:
https://botocore.amazonaws.com/v1/documentation/api/latest/reference/config.html
"""
[docs]
aws_hook_class = DynamoDBHook
[docs]
template_fields: Sequence[str] = aws_template_fields(
"table_name",
"partition_key_name",
"partition_key_value",
"attribute_name",
"attribute_value",
"sort_key_name",
"sort_key_value",
)
def __init__(
self,
table_name: str,
partition_key_name: str,
partition_key_value: str,
attribute_name: str,
attribute_value: str | Iterable[str],
sort_key_name: str | None = None,
sort_key_value: str | None = None,
deferrable: bool = conf.getboolean("operators", "default_deferrable", fallback=False),
**kwargs: Any,
):
super().__init__(**kwargs)
[docs]
self.table_name = table_name
[docs]
self.partition_key_name = partition_key_name
[docs]
self.partition_key_value = partition_key_value
[docs]
self.attribute_name = attribute_name
[docs]
self.attribute_value = attribute_value
[docs]
self.sort_key_name = sort_key_name
[docs]
self.sort_key_value = sort_key_value
[docs]
self.deferrable = deferrable
[docs]
def execute(self, context: Context) -> Any:
if self.deferrable:
self.defer(
trigger=DynamoDBValueSensorTrigger(
table_name=self.table_name,
partition_key_name=self.partition_key_name,
partition_key_value=self.partition_key_value,
attribute_name=self.attribute_name,
attribute_value=self.attribute_value,
sort_key_name=self.sort_key_name,
sort_key_value=self.sort_key_value,
waiter_delay=int(self.poke_interval),
aws_conn_id=self.aws_conn_id,
region_name=self.region_name,
verify=self.verify,
botocore_config=self.botocore_config,
),
method_name="execute_complete",
timeout=timedelta(seconds=self.timeout),
)
else:
super().execute(context=context)
[docs]
def execute_complete(self, context: Context, event: dict | None = None) -> None:
validated_event = validate_execute_complete_event(event)
if validated_event["status"] != "success":
raise RuntimeError(f"Trigger error: event is {validated_event}")
self.log.info("DynamoDB attribute value match found; sensor complete.")
[docs]
def poke(self, context: Context) -> bool:
"""Test DynamoDB item for matching attribute value."""
key = {self.partition_key_name: self.partition_key_value}
msg = (
f"Checking table {self.table_name} for "
f"item Partition Key: {self.partition_key_name}={self.partition_key_value}"
)
if self.sort_key_name and self.sort_key_value:
key = {self.partition_key_name: self.partition_key_value, self.sort_key_name: self.sort_key_value}
msg += f"\nSort Key: {self.sort_key_name}={self.sort_key_value}"
msg += f"\nattribute: {self.attribute_name}={self.attribute_value}"
self.log.info(msg)
table = self.hook.conn.Table(self.table_name)
self.log.info("Table: %s", table)
self.log.info("Key: %s", key)
try:
response = table.get_item(Key=key)
except ClientError as err:
self.log.error(
"Couldn't get %s from table %s.\nError Code: %s\nError Message: %s",
key,
self.table_name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
return False
else:
try:
item_attribute_value = response["Item"][self.attribute_name]
self.log.info("Response: %s", response)
self.log.info("Want: %s = %s", self.attribute_name, self.attribute_value)
self.log.info("Got: %s = %s", self.attribute_name, item_attribute_value)
return item_attribute_value in (
[self.attribute_value] if isinstance(self.attribute_value, str) else self.attribute_value
)
except KeyError:
return False