This is a feature release.

• Adds support for AdminAPI DescribeCluster() and DescribeTopics() (#964, @jainruchir).
• KIP-430: Return authorized operations in Describe Responses. (#964, @jainruchir).
• Adds Rack to the Node type, so AdminAPI calls can expose racks for brokers (currently, all Describe Responses) (#964, @jainruchir).
• KIP-396: completed the implementation with the addition of ListOffsets (#1029).
• Adds cache for Schema Registry client's GetSchemaMetadata (#1042).
• MockCluster can now be shutdown and started again to test broker availability problems (#998, @kkoehler).
• Adds CreateTopic method to the MockCluster. (#1047, @mimikwang).
• Honor HTTPS_PROXY environment variable, if set, for the Schema Registry client (#1065, @finncolman).
• KIP-516: Partial support of topic identifiers. Topic identifiers in metadata response are available through the new DescribeTopics function (#1068).

Fixes

• Fixes a bug in the mock schema registry client where the wrong ID was being returned for pre-registered schema (#971, @srlk).
• The minimum version of Go supported has been changed from 1.16 to 1.17 (#1074).
• Fixes an issue where testing was being imported by a non-test file, testhelpers.go. (#1049, @dmlambea).
• Fixes the optional Coordinator field in ConsumerGroupDescription in case it's not known. It now contains a Node with ID -1 in that case. Avoids a C segmentation fault.
• Fixes an issue with Producer.Flush. It was waiting for queue.buffering.max.ms while flushing (#1013).
• Fixes an issue where consumer methods would not be allowed to run while the consumer was closing, and during the final partition revoke (#1073).

confluent-kafka-go is based on librdkafka v2.3.0, see the librdkafka v2.3.0 release notes for a complete list of changes, enhancements, fixes and upgrade considerations.