213 lines
7.7 KiB
Python
Executable File
213 lines
7.7 KiB
Python
Executable File
# Copyright 2013 IBM Corp
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import time
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from kafka import client
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from kafka import common
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from kafka import consumer
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from kafka import producer
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from oslo_config import cfg
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from oslo_config import types
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try:
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import ujson as json
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except ImportError:
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import json
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from oslo_log import log
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KAFKA_OPTS = [
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cfg.StrOpt('uri', help='Address to kafka server. For example: '
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'uri=192.168.1.191:9092'),
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cfg.StrOpt('group', default='api',
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help='The group name that this service belongs to.'),
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cfg.IntOpt('wait_time', default=1,
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help='The wait time when no messages on kafka queue.'),
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cfg.IntOpt('ack_time', default=20,
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help='The ack time back to kafka.'),
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cfg.IntOpt('max_retry', default=3,
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help='The number of retry when there is a connection error.'),
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cfg.BoolOpt('auto_commit', default=True,
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help='If automatically commmit when consume messages.'),
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cfg.BoolOpt('async', default=True, help='The type of posting.'),
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cfg.BoolOpt('compact', default=True,
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help=('Specify if the message received should be parsed. '
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'If True, message will not be parsed, otherwise '
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'messages will be parsed.')),
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cfg.MultiOpt('partitions', item_type=types.Integer(),
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default=[0],
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help='The sleep time when no messages on kafka queue.'),
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cfg.BoolOpt('drop_data', default=False,
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help=('Specify if received data should be simply dropped. '
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'This parameter is only for testing purposes.')),
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]
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cfg.CONF.register_opts(KAFKA_OPTS, group="kafka_opts")
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LOG = log.getLogger(__name__)
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class KafkaConnection(object):
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def __init__(self, topic):
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if not cfg.CONF.kafka_opts.uri:
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raise Exception('Kafka is not configured correctly! '
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'Use configuration file to specify Kafka '
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'uri, for example: '
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'uri=192.168.1.191:9092')
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self.uri = cfg.CONF.kafka_opts.uri
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self.topic = topic
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self.group = cfg.CONF.kafka_opts.group
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self.wait_time = cfg.CONF.kafka_opts.wait_time
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self.async = cfg.CONF.kafka_opts.async
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self.ack_time = cfg.CONF.kafka_opts.ack_time
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self.max_retry = cfg.CONF.kafka_opts.max_retry
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self.auto_commit = cfg.CONF.kafka_opts.auto_commit
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self.compact = cfg.CONF.kafka_opts.compact
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self.partitions = cfg.CONF.kafka_opts.partitions
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self.drop_data = cfg.CONF.kafka_opts.drop_data
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self._client = None
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self._consumer = None
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self._producer = None
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LOG.debug('Kafka Connection initialized successfully!')
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def _init_client(self, wait_time=None):
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for i in range(self.max_retry):
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try:
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# if there is a client instance, but _init_client is called
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# again, most likely the connection has gone stale, close that
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# connection and reconnect.
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if self._client:
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self._client.close()
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if not wait_time:
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wait_time = self.wait_time
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time.sleep(wait_time)
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self._client = client.KafkaClient(self.uri)
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# when a client is re-initialized, existing consumer should be
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# reset as well.
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self._consumer = None
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self._producer = None
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LOG.debug("Successfully connected to Kafka server at topic: "
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"\"%s\" partitions %s" % (self.topic,
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self.partitions))
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break
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except common.KafkaUnavailableError:
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LOG.error('Kafka server at %s is down.' % self.uri)
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except common.LeaderNotAvailableError:
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LOG.error('Kafka at %s has no leader available.' % self.uri)
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except Exception:
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LOG.error('Kafka at %s initialization failed.' % self.uri)
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# Wait a bit and try again to get a client
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time.sleep(self.wait_time)
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def _init_consumer(self):
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try:
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if not self._client:
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self._init_client()
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self._consumer = consumer.SimpleConsumer(
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self._client, self.group, self.topic,
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auto_commit=self.auto_commit,
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partitions=self.partitions)
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LOG.debug('Consumer was created successfully.')
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except Exception:
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self._consumer = None
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LOG.exception('Kafka (%s) consumer can not be created.' %
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self.uri)
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def _init_producer(self):
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try:
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if not self._client:
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self._init_client()
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self._producer = producer.SimpleProducer(
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self._client, async=self.async, ack_timeout=self.ack_time)
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LOG.debug('Producer was created successfully.')
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except Exception:
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self._producer = None
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LOG.exception('Kafka (%s) producer can not be created.' %
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self.uri)
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def commit(self):
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if self._consumer and self.auto_commit:
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self._consumer.commit()
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def close(self):
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if self._client:
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self._consumer = None
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self._producer = None
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self._client.close()
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def get_messages(self):
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try:
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if not self._consumer:
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self._init_consumer()
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for msg in self._consumer:
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if msg.message:
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LOG.debug(msg.message.value)
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yield msg
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except common.OffsetOutOfRangeError:
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self._consumer.seek(0, 0)
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LOG.error('Seems consumer has been down for a long time.')
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yield None
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except Exception as ex:
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LOG.exception(ex)
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self._consumer = None
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yield None
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def send_messages(self, messages):
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LOG.debug('Prepare to send messages.')
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if not messages or self.drop_data:
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return 204
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code = 400
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try:
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if not self._producer:
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self._init_producer()
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LOG.debug('Start sending messages to kafka.')
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if self.compact:
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self._producer.send_messages(self.topic, messages)
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else:
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data = json.loads(messages)
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LOG.debug('Msg parsed successfully.')
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if isinstance(data, list):
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for item in data:
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self._producer.send_messages(
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self.topic, json.dumps(item))
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else:
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self._producer.send_messages(self.topic, messages)
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LOG.debug('Message posted successfully.')
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code = 204
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except (common.KafkaUnavailableError,
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common.LeaderNotAvailableError):
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self._client = None
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code = 503
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LOG.exception('Error occurred while posting data to Kafka.')
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except ValueError:
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code = 406
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LOG.exception('Message %s is not valid json.' % messages)
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except Exception:
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code = 500
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LOG.exception('Unknown error.')
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return code
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