json_consumer_encryption.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# Copyright 2024 Confluent Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


# A simple example demonstrating use of JSONDeserializer.

import argparse

from confluent_kafka import Consumer
from confluent_kafka.schema_registry import SchemaRegistryClient
from confluent_kafka.schema_registry.json_schema import JSONDeserializer
from confluent_kafka.schema_registry.rules.encryption.awskms.aws_driver import AwsKmsDriver
from confluent_kafka.schema_registry.rules.encryption.azurekms.azure_driver import AzureKmsDriver
from confluent_kafka.schema_registry.rules.encryption.encrypt_executor import FieldEncryptionExecutor
from confluent_kafka.schema_registry.rules.encryption.gcpkms.gcp_driver import GcpKmsDriver
from confluent_kafka.schema_registry.rules.encryption.hcvault.hcvault_driver import HcVaultKmsDriver
from confluent_kafka.schema_registry.rules.encryption.localkms.local_driver import LocalKmsDriver
from confluent_kafka.serialization import MessageField, SerializationContext


class User(object):
    """
    User record

    Args:
        name (str): User's name
        favorite_number (int): User's favorite number
        favorite_color (str): User's favorite color
    """

    def __init__(self, name=None, favorite_number=None, favorite_color=None):
        self.name = name
        self.favorite_number = favorite_number
        self.favorite_color = favorite_color


def dict_to_user(obj, ctx):
    """
    Converts object literal(dict) to a User instance.

    Args:
        ctx (SerializationContext): Metadata pertaining to the serialization
            operation.
        obj (dict): Object literal(dict)
    """

    if obj is None:
        return None

    return User(name=obj['name'], favorite_number=obj['favorite_number'], favorite_color=obj['favorite_color'])


def main(args):
    # Register the KMS drivers and the field-level encryption executor
    AwsKmsDriver.register()
    AzureKmsDriver.register()
    GcpKmsDriver.register()
    HcVaultKmsDriver.register()
    LocalKmsDriver.register()
    FieldEncryptionExecutor.register()

    topic = args.topic

    # When using Data Contract rules, a schema should not be passed to the
    # JSONDeserializer. The schema is fetched from the Schema Registry.
    schema_str = None

    sr_conf = {'url': args.schema_registry}
    schema_registry_client = SchemaRegistryClient(sr_conf)
    rule_conf = None
    # KMS credentials can be passed as follows
    # rule_conf = {'secret.access.key': 'xxx', 'access.key.id': 'yyy'}
    # Alternatively, the KMS credentials can be set via environment variables

    json_deserializer = JSONDeserializer(schema_str, dict_to_user, schema_registry_client, rule_conf=rule_conf)

    consumer_conf = {
        'bootstrap.servers': args.bootstrap_servers,
        'group.id': args.group,
        'auto.offset.reset': "earliest",
    }

    consumer = Consumer(consumer_conf)
    consumer.subscribe([topic])

    while True:
        try:
            # SIGINT can't be handled when polling, limit timeout to 1 second.
            msg = consumer.poll(1.0)
            if msg is None:
                continue

            user = json_deserializer(msg.value(), SerializationContext(msg.topic(), MessageField.VALUE))

            if user is not None:
                print(
                    "User record {}: name: {}\n"
                    "\tfavorite_number: {}\n"
                    "\tfavorite_color: {}\n".format(msg.key(), user.name, user.favorite_number, user.favorite_color)
                )
        except KeyboardInterrupt:
            break

    consumer.close()


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description="JSONDeserializer example")
    parser.add_argument('-b', dest="bootstrap_servers", required=True, help="Bootstrap broker(s) (host[:port])")
    parser.add_argument('-s', dest="schema_registry", required=True, help="Schema Registry (http(s)://host[:port]")
    parser.add_argument('-t', dest="topic", default="example_serde_json", help="Topic name")
    parser.add_argument('-g', dest="group", default="example_serde_json", help="Consumer group")

    main(parser.parse_args())