Prompt: What does this code do?

class KafkaOptions(PipelineOptions):
    @classmethod
    def _add_argparse_args(cls, parser):
        parser.add_argument(
            '--bootstrap_servers',
            default="localhost:9092",
            help='Apache Kafka bootstrap servers'
        )
        parser.add_argument(
            '--topic',
            default="your-topic",
            help='Apache Kafka topic'
        )

options = KafkaOptions()

with beam.Pipeline(options=options) as p:
    output = (p | "Read from Kafka" >> ReadFromKafka(
        consumer_config={'bootstrap.servers': options.bootstrap_servers},
        topics=[options.topic],
        with_metadata=False
        )
        | "Log Data" >> Map(logging.info))

Response: This code uses the Apache Beam KafkaIO Python connector to read data from an Apache Kafka topic topic on Kafka bootstrap servers bootstrap_servers.

The ReadFromKafka transform is a cross-language transform that is implemented in Java and is available in Python, Go, and Typescript via X-language. The Python SDK connects to a Java expansion service to expand these transforms during pipeline execution. For more information about cross-language transforms, see Apache Beam Multi-language pipelines.

with beam.Pipeline(options=options) as p:
    output = (p | "Read from Kafka" >> ReadFromKafka(
        consumer_config={'bootstrap.servers': options.bootstrap_servers},
        topics=[options.topic],
        with_metadata=False
        )
        | "Log Data" >> Map(logging.info))

The required arguments for the ReadFromKafka transform are consumer_config and topics. You can use the consumer_config argument to specify the Kafka bootstrap servers, the topics argument to specify the Kafka topic to read data from, and the with_metadata argument to specify whether to include Kafka metadata in the output PCollection. The default value for the with_metadata argument is False.

The KafkaReadOptions class defines the command-line arguments bootstrap_servers and topic, which are used to configure the ReadFromKafka transform. These arguments are parsed from the command line using pipeline options.

class KafkaOptions(PipelineOptions):
    @classmethod
    def _add_argparse_args(cls, parser):
        parser.add_argument(
            '--bootstrap_servers',
            default="localhost:9092",
            help='Apache Kafka bootstrap servers'
        )
        parser.add_argument(
            '--topic',
            default="your-topic",
            help='Apache Kafka topic'
        )

options = KafkaOptions()

For more information about how to use the KafkaIO connector with the Python SDK for Apache Beam, see KafkaIO module.