Source code for airflow.contrib.sensors.redis_pub_sub_sensor

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from airflow.sensors.base_sensor_operator import BaseSensorOperator
from airflow.utils.decorators import apply_defaults
from airflow.contrib.hooks.redis_hook import RedisHook

[docs]class RedisPubSubSensor(BaseSensorOperator): """ Redis sensor for reading a message from pub sub channels """
[docs] template_fields = ('channels',)
[docs] ui_color = '#f0eee4'
@apply_defaults def __init__(self, channels, redis_conn_id, *args, **kwargs): """ Create a new RedisPubSubSensor and subscribe to the channels :param channels: The channels to be subscribed to (templated) :type channels: str or list of str :param redis_conn_id: the redis connection id :type redis_conn_id: str """ super(RedisPubSubSensor, self).__init__(*args, **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): """ 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 :type context: dict :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

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