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

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from __future__ import annotations

from functools import cached_property
from typing import TYPE_CHECKING, Sequence

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

if TYPE_CHECKING:
    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: list[str] | str, redis_conn_id: str, **kwargs) -> None: super().__init__(**kwargs) self.channels = channels self.redis_conn_id = redis_conn_id @cached_property
[docs] def pubsub(self): hook = RedisHook(redis_conn_id=self.redis_conn_id).get_conn().pubsub() hook.subscribe(self.channels) return hook
[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 """ self.log.info("RedisPubSubSensor checking for message on channels: %s", self.channels) message = self.pubsub.get_message() self.log.info("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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