# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
from __future__ import annotations
import asyncio
from collections.abc import AsyncIterator, Iterable
from functools import cached_property
from typing import Any
from boto3.dynamodb.types import TypeDeserializer
from botocore.exceptions import ClientError
from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
from airflow.providers.amazon.version_compat import AIRFLOW_V_3_0_PLUS
if AIRFLOW_V_3_0_PLUS:
from airflow.triggers.base import BaseEventTrigger, TriggerEvent
else:
from airflow.triggers.base import ( # type: ignore
BaseTrigger as BaseEventTrigger,
TriggerEvent,
)
[docs]
class DynamoDBValueSensorTrigger(BaseEventTrigger):
"""
Asynchronously poll a DynamoDB item until the given attribute matches one of the expected values.
The polling uses the low-level DynamoDB client (aiobotocore exposes clients only, not the
boto3 resource API used by ``DynamoDBHook``), so keys are sent as typed string attributes,
matching the string-typed key parameters of :class:`~airflow.providers.amazon.aws.sensors.dynamodb.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: expected DynamoDB attribute value (or values, any of which matches)
:param sort_key_name: (optional) DynamoDB sort key name
:param sort_key_value: (optional) DynamoDB sort key value
:param waiter_delay: The time in seconds to wait between DynamoDB API calls
:param aws_conn_id: The Airflow connection used for AWS credentials.
: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
"""
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,
waiter_delay: int = 60,
aws_conn_id: str | None = "aws_default",
region_name: str | None = None,
verify: bool | str | None = None,
botocore_config: dict | None = None,
):
[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] if isinstance(attribute_value, str) else list(attribute_value)
)
[docs]
self.sort_key_name = sort_key_name
[docs]
self.sort_key_value = sort_key_value
[docs]
self.waiter_delay = waiter_delay
[docs]
self.aws_conn_id = aws_conn_id
[docs]
self.region_name = region_name
[docs]
self.botocore_config = botocore_config
[docs]
def serialize(self) -> tuple[str, dict[str, Any]]:
return (
self.__class__.__module__ + "." + self.__class__.__qualname__,
{
"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": self.waiter_delay,
"aws_conn_id": self.aws_conn_id,
"region_name": self.region_name,
"verify": self.verify,
"botocore_config": self.botocore_config,
},
)
@cached_property
[docs]
def hook(self) -> AwsBaseHook:
# DynamoDBHook is resource-based, but async connections are only available for
# clients, so the trigger talks to DynamoDB through a client-type hook instead.
return AwsBaseHook(
aws_conn_id=self.aws_conn_id,
region_name=self.region_name,
verify=self.verify,
config=self.botocore_config,
client_type="dynamodb",
)
@property
[docs]
def key(self) -> dict[str, Any]:
key = {self.partition_key_name: {"S": self.partition_key_value}}
if self.sort_key_name and self.sort_key_value:
key[self.sort_key_name] = {"S": self.sort_key_value}
return key
[docs]
async def poke(self, client: Any) -> bool:
"""Test the DynamoDB item for a matching attribute value, mirroring the sensor's poke."""
self.log.info(
"Checking table %s for item with key %s, waiting for attribute %s to be one of %s",
self.table_name,
self.key,
self.attribute_name,
self.attribute_value,
)
try:
response = await client.get_item(TableName=self.table_name, Key=self.key)
except ClientError as err:
# Same tolerance as the sensor's poke: log and keep trying until the task times out.
self.log.error(
"Couldn't get %s from table %s.\nError Code: %s\nError Message: %s",
self.key,
self.table_name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
return False
try:
typed_attribute_value = response["Item"][self.attribute_name]
except KeyError:
return False
item_attribute_value = TypeDeserializer().deserialize(typed_attribute_value)
self.log.info("Got: %s = %s", self.attribute_name, item_attribute_value)
return item_attribute_value in self.attribute_value
[docs]
async def run(self) -> AsyncIterator[TriggerEvent]:
while True:
# This loop runs until the timeout set in the sensor's self.defer call is reached.
async with await self.hook.get_async_conn() as client:
if await self.poke(client=client):
yield TriggerEvent({"status": "success"})
return
await asyncio.sleep(self.waiter_delay)