platypush/platypush/plugins/kafka.py

77 lines
2.2 KiB
Python

import json
import logging
from platypush.context import get_backend
from platypush.plugins import Plugin, action
class KafkaPlugin(Plugin):
"""
Plugin to send messages to an Apache Kafka instance (https://kafka.apache.org/)
Triggers:
* :class:`platypush.message.event.kafka.KafkaMessageEvent` when a new message is received on the consumer topic.
Requires:
* **kafka** (``pip install kafka-python``)
"""
def __init__(self, server=None, port=9092, **kwargs):
"""
:param server: Default Kafka server name or address. If None (default), then it has to be specified upon
message sending.
:type server: str
:param port: Default Kafka server port (default: 9092).
:type port: int
"""
super().__init__(**kwargs)
self.server = '{server}:{port}'.format(server=server, port=port) \
if server else None
self.producer = None
# Kafka can be veryyyy noisy
logging.getLogger('kafka').setLevel(logging.ERROR)
@action
def send_message(self, msg, topic, server=None):
"""
:param msg: Message to send - as a string, bytes stream, JSON, Platypush message, dictionary, or anything
that implements ``__str__``
:param topic: Topic to send the message to.
:type topic: str
:param server: Kafka server name or address + port (format: ``host:port``). If None, then the default server
will be used
:type server: str
"""
from kafka import KafkaProducer
if not server:
if not self.server:
try:
kafka_backend = get_backend('kafka')
server = kafka_backend.server
except Exception as e:
raise RuntimeError(f'No Kafka server nor default server specified: {str(e)}')
else:
server = self.server
if isinstance(msg, dict) or isinstance(msg, list):
msg = json.dumps(msg)
msg = str(msg).encode('utf-8')
producer = KafkaProducer(bootstrap_servers=server)
producer.send(topic, msg)
producer.flush()
# vim:sw=4:ts=4:et: