Protobuf deserialization

To deserialize topics containing data in Protobuf format, you can set topics mapping: for each topic-regex you can specify descriptor-file-base64 (descriptor file encoded to Base64 format), or you can put descriptor files in descriptors-folder and specify descriptor-file name, also specify corresponding message types for keys and values. If, for example, keys are not in Protobuf format, key-message-type can be omitted, the same for value-message-type. . It's important to keep in mind that both key-message-type and value-message-type require a fully-qualified name. This configuration can be specified for each Kafka cluster.

Example configuration can look like as follows:

akhq:
  connections:
    kafka:
      properties:
        # standard kafka properties
      deserialization:
        protobuf:
          descriptors-folder: "/app/protobuf_desc"
          topics-mapping:
            - topic-regex: "album.*"
              descriptor-file-base64: "Cs4BCgthbGJ1bS5wcm90bxIXY29tLm5ldGNyYWNrZXIucHJvdG9idWYidwoFQWxidW0SFAoFdGl0bGUYASABKAlSBXRpdGxlEhYKBmFydGlzdBgCIAMoCVIGYXJ0aXN0EiEKDHJlbGVhc2VfeWVhchgDIAEoBVILcmVsZWFzZVllYXISHQoKc29uZ190aXRsZRgEIAMoCVIJc29uZ1RpdGxlQiUKF2NvbS5uZXRjcmFja2VyLnByb3RvYnVmQgpBbGJ1bVByb3RvYgZwcm90bzM="
              value-message-type: "org.akhq.utils.Album"
            - topic-regex: "film.*"
              descriptor-file-base64: "CuEBCgpmaWxtLnByb3RvEhRjb20uY29tcGFueS5wcm90b2J1ZiKRAQoERmlsbRISCgRuYW1lGAEgASgJUgRuYW1lEhoKCHByb2R1Y2VyGAIgASgJUghwcm9kdWNlchIhCgxyZWxlYXNlX3llYXIYAyABKAVSC3JlbGVhc2VZZWFyEhoKCGR1cmF0aW9uGAQgASgFUghkdXJhdGlvbhIaCghzdGFycmluZxgFIAMoCVIIc3RhcnJpbmdCIQoUY29tLmNvbXBhbnkucHJvdG9idWZCCUZpbG1Qcm90b2IGcHJvdG8z"
              value-message-type: "org.akhq.utils.Film"
            - topic-regex: "test.*"
              descriptor-file: "other.desc"
              key-message-type: "org.akhq.utils.Row"
              value-message-type: "org.akhq.utils.Envelope"

More examples about Protobuf deserialization can be found in tests. Info about the descriptor files generation can be found in test resources.