Confluent Schema Registry Metadata

Confluent-Schema-Registry-Metadata.md

Confluent Schema Registry Metadata

Prior to v7.4, schema registry did not support any custom metadata associated with a schema uploaded to the schema registry.

So the following mapping between

• the version of a jar artifact containing a schema content
• and the id and version of the schema in the schema registry can only be derived by comparing the content of the schemas in different schema registry environments (using POST /subjects/(string: subject)).

Starting with v7.4, it is possible to add any metadata properties to the schema registration call:

curl -s --show-error --fail --insecure --user : -H 'Content-Type: application/vnd.schemaregistry.v1+json' http://localhost:9080/subjects/test-topic-value/versions --data '{
  "schema": "{\n  \"type\" : \"record\",\n  \"name\" : \"TestSchema\",\n  \"namespace\" : \"com.droidablebee.avro\",\n  \"fields\" : [ {\n    \"name\" : \"id\",\n    \"type\" : \"string\"\n  }, {\n    \"name\" : \"description\",\n    \"type\" : [ \"null\", \"string\" ],\n    \"default\" : null\n  } ]\n}",
  "metadata": {
    "properties": {
      "artifact": "test-schema-0.0.7.1.zip"
    }
  }
}'

And then see the metadata returned by http://localhost:9080/subjects/test-topic-value/versions/1

{
  "subject": "test-topic-value",
  "version": 1,
  "id": 2,
  "metadata": {
    "properties": {
      "artifact": "test-schema-0.0.7.1.zip"
    }
  },
  "schema": "{\"type\":\"record\",\"name\":\"TestSchema\",\"namespace\":\"com.droidablebee.avro\",\"fields\":[{\"name\":\"id\",\"type\":\"string\"},{\"name\":\"description\",\"type\":[\"null\",\"string\"],\"default\":null}]}"
}

Tested using confluentinc/cp-schema-registry:7.4.1 and confluentinc/cp-schema-registry:7.5.0 docker images.

See https://docs.confluent.io/platform/7.4/schema-registry/develop/api.html and https://docs.confluent.io/platform/7.5/schema-registry/fundamentals/data-contracts.html#metadata-properties for more details.

When using /subjects/$subject API to check whether a schema is already registered or not, the payload must match the schema registration payload, including metadata properties.