Schema Registry Maven Plugin¶

A Maven plugin for Schema Registry is available to help throughout the development process, with configuration options as listed below.

Tip

There is no official out-of-the-box Gradle plugin available for Schema Registry. However, you can reference any of these plugins in your Maven pom.xml (Project Object Model file):

GitHub Imflog Kafka Schema Registry Gradle Plugin
com.commercehub.gradle.plugin.avro (link to GitHub repository for this plugin is here)
Maven plugin, used in the pom.xml example file by Avro clients for the Schema Registry Tutorial

schema-registry:download¶

The download goal is used to pull down schemas from a Schema Registry server. This plugin is used to download Avro schemas for the requested subjects and write them to a folder on the local file system.

schemaRegistryUrls

Schema Registry URLs to connect to.

Type: String[]
Required: true

outputDirectory

Output directory to write the schemas to.

Type: File
Required: true

schemaExtension

The file extension to use for the output file name. This must begin with a ‘.’ character.

Type: File
Required: false
Default: .avsc

subjectPatterns

The subject patterns to download. This is a list of regular expressions. Patterns must match the entire subject name.

Type: String[]
Required: true

<plugin>
    <groupId>io.confluent</groupId>
    <artifactId>kafka-schema-registry-maven-plugin</artifactId>
    <version>5.5.0</version>
    <configuration>
        <schemaRegistryUrls>
            <param>http://192.168.99.100:8081</param>
        </schemaRegistryUrls>
        <outputDirectory>src/main/avro</outputDirectory>
        <subjectPatterns>
            <param>^TestSubject000-(key|value)$</param>
        </subjectPatterns>
    </configuration>
</plugin>

schema-registry:test-compatibility¶

This goal is used to read schemas from the local file system and test them for compatibility against the Schema Registry server(s). This goal can be used in a continuous integration pipeline to ensure that schemas in the project are compatible with the schemas in another environment.

schemaRegistryUrls

Schema Registry URLs to connect to.

Type: String[]
Required: true

subjects

Map containing subject to schema path of the subjects to be registered.

Type: Map<String, File>
Required: true

schemaTypes

String that specifies the schema type.

Type: String (one of AVRO (default), JSON, PROTOBUF)
Required: false
Default: AVRO

references

Map containing a reference name and a subject.

Type: Map<String, Reference[]>
Required: false

The following example uses the plugin to configure three subjects (order, product, and customer) using schema type: AVRO

<plugin>
    <groupId>io.confluent</groupId>
    <artifactId>kafka-schema-registry-maven-plugin</artifactId>
    <version>5.5.0</version>
    <configuration>
        <schemaRegistryUrls>
            <param>http://192.168.99.100:8081</param>
        </schemaRegistryUrls>
        <subjects>
            <order>src/main/avro/order.avsc</order>
            <product>src/main/avro/product.avsc</product>
            <customer>src/main/avro/customer.avsc</customer>
        </subjects>
        <schemaTypes>
            <order>AVRO</order>
            <product>AVRO</product>
            <customer>AVRO</customer>
        </schemaTypes>
        <references>
            <order>
              <reference>
                  <name>com.acme.Product</name>
                  <subject>product</subject>
              </reference>
              <reference>
                  <name>com.acme.Customer</name>
                  <subject>customer</subject>
              </reference>
            </order>
        </references>
    </configuration>
    <goals>
        <goal>test-compatibility</goal>
    </goals>
</plugin>

schema-registry:register¶

This goal is used to read schemas from the local file system and register them on the target Schema Registry server(s). This goal can be used in a continuous deployment pipeline to push schemas to a new environment.

schemaRegistryUrls

Schema Registry URLs to connect to.

Type: String[]
Required: true

subjects

Map containing subject to schema path of the subjects to be registered.

Type: Map<String, File>
Required: true

schemaTypes

String that specifies the schema type.

Type: String (one of AVRO (default), JSON, PROTOBUF)
Required: false
Default: AVRO

references

Map containing a reference name and a subject.

Type: Map<String, Reference[]>
Required: false

The following example uses the plugin to configure three subjects (order, product, and customer) using schema type: AVRO

<plugin>
    <groupId>io.confluent</groupId>
    <artifactId>kafka-schema-registry-maven-plugin</artifactId>
    <version>5.5.0</version>
    <configuration>
        <schemaRegistryUrls>
            <param>http://192.168.99.100:8081</param>
        </schemaRegistryUrls>
        <subjects>
            <order>src/main/avro/order.avsc</order>
            <product>src/main/avro/product.avsc</product>
            <customer>src/main/avro/customer.avsc</customer>
        </subjects>
        <schemaTypes>
            <order>AVRO</order>
            <product>AVRO</product>
            <customer>AVRO</customer>
        </schemaTypes>
        <references>
            <order>
              <reference>
                  <name>com.acme.Product</name>
                  <subject>product</subject>
              </reference>
              <reference>
                  <name>com.acme.Customer</name>
                  <subject>customer</subject>
              </reference>
            </order>
        </references>
    </configuration>
    <goals>
        <goal>register</goal>
    </goals>
</plugin>

Schema Registry Maven Plugin¶

schema-registry:download¶

schema-registry:test-compatibility¶

schema-registry:register¶

Suggested Reading¶