4 from aiokafka
import AIOKafkaConsumer
5 from aiokafka
import AIOKafkaProducer
6 from aiokafka
.errors
import KafkaError
7 from msgbase
import MsgBase
, MsgException
11 class MsgKafka(MsgBase
):
12 def __init__(self
, logger_name
='msg'):
13 self
.logger
= logging
.getLogger(logger_name
)
19 def connect(self
, config
):
21 if "logger_name" in config
:
22 self
.logger
= logging
.getLogger(config
["logger_name"])
23 self
.host
= config
["host"]
24 self
.port
= config
["port"]
25 self
.loop
= asyncio
.get_event_loop()
26 self
.broker
= str(self
.host
) + ":" + str(self
.port
)
28 except Exception as e
: # TODO refine
29 raise MsgException(str(e
))
34 except Exception as e
: # TODO refine
35 raise MsgException(str(e
))
37 def write(self
, topic
, key
, msg
):
39 self
.loop
.run_until_complete(self
.aiowrite(topic
=topic
, key
=key
,
40 msg
=yaml
.safe_dump(msg
, default_flow_style
=True),
43 except Exception as e
:
44 raise MsgException("Error writing {} topic: {}".format(topic
, str(e
)))
46 def read(self
, topic
):
48 Read from one or several topics. it is non blocking returning None if nothing is available
49 :param topic: can be str: single topic; or str list: several topics
50 :return: topic, key, message; or None
53 return self
.loop
.run_until_complete(self
.aioread(topic
, self
.loop
))
56 except Exception as e
:
57 raise MsgException("Error reading {} topic: {}".format(topic
, str(e
)))
59 async def aiowrite(self
, topic
, key
, msg
, loop
=None):
64 self
.producer
= AIOKafkaProducer(loop
=loop
, key_serializer
=str.encode
, value_serializer
=str.encode
,
65 bootstrap_servers
=self
.broker
)
66 await self
.producer
.start()
67 await self
.producer
.send(topic
=topic
, key
=key
, value
=yaml
.safe_dump(msg
, default_flow_style
=True))
68 except Exception as e
:
69 raise MsgException("Error publishing topic '{}', key '{}': {}".format(topic
, key
, e
))
71 await self
.producer
.stop()
73 async def aioread(self
, topic
, loop
=None, callback
=None, *args
):
75 Asyncio read from one or several topics. It blocks
76 :param topic: can be str: single topic; or str list: several topics
77 :param loop: asyncio loop
78 :callback: callback function that will handle the message in kafka bus
79 :*args: optional arguments for callback function
80 :return: topic, key, message
86 if isinstance(topic
, (list, tuple)):
91 self
.consumer
= AIOKafkaConsumer(loop
=loop
, bootstrap_servers
=self
.broker
)
92 await self
.consumer
.start()
93 self
.consumer
.subscribe(topic_list
)
95 async for message
in self
.consumer
:
97 callback(message
.topic
, yaml
.load(message
.key
), yaml
.load(message
.value
), *args
)
99 return message
.topic
, yaml
.load(message
.key
), yaml
.load(message
.value
)
100 except KafkaError
as e
:
101 raise MsgException(str(e
))
103 await self
.consumer
.stop()