4 from aiokafka
import AIOKafkaConsumer
5 from aiokafka
import AIOKafkaProducer
6 from aiokafka
.errors
import KafkaError
7 from osm_common
.msgbase
import MsgBase
, MsgException
10 __author__
= "Alfonso Tierno <alfonso.tiernosepulveda@telefonica.com>, " \
11 "Guillermo Calvino <guillermo.calvinosanchez@altran.com>"
14 class MsgKafka(MsgBase
):
15 def __init__(self
, logger_name
='msg'):
16 self
.logger
= logging
.getLogger(logger_name
)
24 def connect(self
, config
):
26 if "logger_name" in config
:
27 self
.logger
= logging
.getLogger(config
["logger_name"])
28 self
.host
= config
["host"]
29 self
.port
= config
["port"]
30 self
.loop
= asyncio
.get_event_loop()
31 self
.broker
= str(self
.host
) + ":" + str(self
.port
)
33 except Exception as e
: # TODO refine
34 raise MsgException(str(e
))
39 except Exception as e
: # TODO refine
40 raise MsgException(str(e
))
42 def write(self
, topic
, key
, msg
):
44 self
.loop
.run_until_complete(self
.aiowrite(topic
=topic
, key
=key
,
45 msg
=yaml
.safe_dump(msg
, default_flow_style
=True),
48 except Exception as e
:
49 raise MsgException("Error writing {} topic: {}".format(topic
, str(e
)))
51 def read(self
, topic
):
53 Read from one or several topics. it is non blocking returning None if nothing is available
54 :param topic: can be str: single topic; or str list: several topics
55 :return: topic, key, message; or None
58 return self
.loop
.run_until_complete(self
.aioread(topic
, self
.loop
))
61 except Exception as e
:
62 raise MsgException("Error reading {} topic: {}".format(topic
, str(e
)))
64 async def aiowrite(self
, topic
, key
, msg
, loop
=None):
69 self
.producer
= AIOKafkaProducer(loop
=loop
, key_serializer
=str.encode
, value_serializer
=str.encode
,
70 bootstrap_servers
=self
.broker
)
71 await self
.producer
.start()
72 await self
.producer
.send(topic
=topic
, key
=key
, value
=yaml
.safe_dump(msg
, default_flow_style
=True))
73 except Exception as e
:
74 raise MsgException("Error publishing topic '{}', key '{}': {}".format(topic
, key
, e
))
76 await self
.producer
.stop()
78 async def aioread(self
, topic
, loop
=None, callback
=None, *args
):
80 Asyncio read from one or several topics. It blocks
81 :param topic: can be str: single topic; or str list: several topics
82 :param loop: asyncio loop
83 :callback: callback function that will handle the message in kafka bus
84 :*args: optional arguments for callback function
85 :return: topic, key, message
91 if isinstance(topic
, (list, tuple)):
96 self
.consumer
= AIOKafkaConsumer(loop
=loop
, bootstrap_servers
=self
.broker
)
97 await self
.consumer
.start()
98 self
.consumer
.subscribe(topic_list
)
100 async for message
in self
.consumer
:
102 callback(message
.topic
, yaml
.load(message
.key
), yaml
.load(message
.value
), *args
)
104 return message
.topic
, yaml
.load(message
.key
), yaml
.load(message
.value
)
105 except KafkaError
as e
:
106 raise MsgException(str(e
))
108 await self
.consumer
.stop()