Source code for airflow.providers.redis.sensors.redis_pub_sub

# 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
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.

from typing import TYPE_CHECKING, List, Sequence, Union

from airflow.providers.redis.hooks.redis import RedisHook
from airflow.sensors.base import BaseSensorOperator

    from airflow.utils.context import Context

[docs]class RedisPubSubSensor(BaseSensorOperator): """ Redis sensor for reading a message from pub sub channels :param channels: The channels to be subscribed to (templated) :param redis_conn_id: the redis connection id """
[docs] template_fields: Sequence[str] = ('channels',)
[docs] ui_color = '#f0eee4'
def __init__(self, *, channels: Union[List[str], str], redis_conn_id: str, **kwargs) -> None: super().__init__(**kwargs) self.channels = channels self.redis_conn_id = redis_conn_id self.pubsub = RedisHook(redis_conn_id=self.redis_conn_id).get_conn().pubsub() self.pubsub.subscribe(self.channels)
[docs] def poke(self, context: 'Context') -> bool: """ Check for message on subscribed channels and write to xcom the message with key ``message`` An example of message ``{'type': 'message', 'pattern': None, 'channel': b'test', 'data': b'hello'}`` :param context: the context object :return: ``True`` if message (with type 'message') is available or ``False`` if not """'RedisPubSubSensor checking for message on channels: %s', self.channels) message = self.pubsub.get_message()'Message %s from channel %s', message, self.channels) # Process only message types if message and message['type'] == 'message': context['ti'].xcom_push(key='message', value=message) self.pubsub.unsubscribe(self.channels) return True return False

Was this entry helpful?