datahub/metadata-service/schema-registry-servlet/scripts/README.md

Kafka Message Extraction Script

This script extracts the first message from multiple Kafka topics to create binary test fixtures for integration testing.

Usage

cd metadata-service/schema-registry-servlet/scripts
chmod +x extract_kafka_messages.sh
./extract_kafka_messages.sh

What It Does

1. Extracts messages from these topics:

   • DataHubUpgradeHistory_v1
   • FailedMetadataChangeProposal_v1
   • MetadataChangeLog_Timeseries_v1
   • MetadataChangeLog_Versioned_v1
   • MetadataChangeProposal_v1

2. Creates binary fixtures in ../src/test/resources/v1/:

   • {TopicName}_test_fixture.bin for each topic with messages

3. Shows message details:

   • File size and hex dump of first 32 bytes
   • Deserialized content preview

Prerequisites

• kcat installed (brew install kcat on macOS)
• Local Kafka running on localhost:9092
• Schema registry accessible at http://localhost:8080/schema-registry/api

Output

The script will create binary fixture files that can be used in your integration tests to verify raw message handling capabilities.