Updated on 2022-02-21 GMT+08:00

Python

This section describes how to access a Kafka premium instance using a Kafka client in Python on the Linux CentOS, including how to install the client, and produce and consume messages.

Before getting started, ensure that you have collected the information listed in Collecting Connection Information.

Preparing the Environment

  • Python

    Generally, Python is pre-installed in the system. Enter python in a CLI. If the following information is displayed, Python has already been installed.

    [root@ecs-test python-kafka]# python3
    Python 3.7.1 (default, Jul  5 2020, 14:37:24) 
    [GCC 4.8.5 20150623 (Red Hat 4.8.5-39)] on linux
    Type "help", "copyright", "credits" or "license" for more information.
    >>>

    If Python is not installed, run the following command:

    yum install python

  • Kafka clients in Python

    Run the following command to install a Python client of the recommended version:

    pip install kafka-python==2.0.1

Producing Messages

Replace the following information in bold with the actual values.

  • With SASL
    from kafka import KafkaProducer
    import ssl
    ##Connection information
    conf = {
        'bootstrap_servers': ["ip1:port1","ip2:port2","ip3:port3"],
        'topic_name': 'topic_name',
        'sasl_plain_username': 'username',
        'sasl_plain_password': 'password'
    }
    
    context = ssl.create_default_context()
    context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
    context.verify_mode = ssl.CERT_REQUIRED
    ##Certificate
    context.load_verify_locations("phy_ca.crt")
    
    print('start producer')
    producer = KafkaProducer(bootstrap_servers=conf['bootstrap_servers'],
                            sasl_mechanism="PLAIN",
                            ssl_context=context,
                            security_protocol='SASL_SSL',
                            sasl_plain_username=conf['sasl_plain_username'],
                            sasl_plain_password=conf['sasl_plain_password'])
    
    data = bytes("hello kafka!", encoding="utf-8")
    producer.send(conf['topic_name'], data)
    producer.close()
    print('end producer')
  • Without SASL
    from kafka import KafkaProducer
    
    conf = {
        'bootstrap_servers': ["ip1:port1","ip2:port2","ip3:port3"],
        'topic_name': 'topic-name',
    }
    
    print('start producer')
    producer = KafkaProducer(bootstrap_servers=conf['bootstrap_servers'])
    
    data = bytes("hello kafka!", encoding="utf-8")
    producer.send(conf['topic_name'], data)
    producer.close()
    print('end producer')

Consuming Messages

  • With SASL
    from kafka import KafkaConsumer
    import ssl
    ##Connection information
    conf = {
        'bootstrap_servers': ["ip1:port1","ip2:port2","ip3:port3"],
        'topic_name': 'topic_name',
        'sasl_plain_username': 'username',
        'sasl_plain_password': 'password',
        'consumer_id': 'consumer_id'
    }
    
    context = ssl.create_default_context()
    context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
    context.verify_mode = ssl.CERT_REQUIRED
    ##Certificate
    context.load_verify_locations("phy_ca.crt")
    
    print('start consumer')
    consumer = KafkaConsumer(conf['topic_name'],
                            bootstrap_servers=conf['bootstrap_servers'],
                            group_id=conf['consumer_id'],
                            sasl_mechanism="PLAIN",
                            ssl_context=context,
                            security_protocol='SASL_SSL',
                            sasl_plain_username=conf['sasl_plain_username'],
                            sasl_plain_password=conf['sasl_plain_password'])
    
    for message in consumer:
        print("%s:%d:%d: key=%s value=%s" % (message.topic, message.partition,message.offset, message.key,message.value))
    
    print('end consumer')
  • Without SASL

    Replace the information in bold with the actual values.

    from kafka import KafkaConsumer
    
    conf = {
        'bootstrap_servers': ["ip1:port1","ip2:port2","ip3:port3"],
        'topic_name': 'topic-name',
        'consumer_id': 'consumer-id'
    }
    
    print('start consumer')
    consumer = KafkaConsumer(conf['topic_name'],
                            bootstrap_servers=conf['bootstrap_servers'],
                            group_id=conf['consumer_id'])
    
    for message in consumer:
        print("%s:%d:%d: key=%s value=%s" % (message.topic, message.partition,message.offset, message.key,message.value))
    
    print('end consumer')