Bug: Two BinderConfigurationPropertiesBeans are created

Using the Spring Initializr I create a pom for a vanilla spring-boot application containing Cloud Stream and Spring for Kafka Streams:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Hoxton.SR1</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka-streams</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-stream</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-stream-binder-kafka-streams</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-stream-test-support</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

WIth a very simple application class:

package test;

import org.apache.kafka.streams.kstream.KStream;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

import java.util.function.Consumer;

@SpringBootApplication
public class KafkaTest {

	@Bean
	public Consumer<KStream<Object, String>> process() {
		return input ->
			input.foreach((key, value) -> {
				System.out.println("Key: " + key + " Value: " + value);
			});
	}

	public static void main(String[] args) {
		SpringApplication.run(KafkaTest.class, args);
	}

}

Running this application will fail:

---

APPLICATION FAILED TO START

---

Description:

Parameter 0 of method provisioningProvider in org.springframework.cloud.stream.binder.kafka.streams.KStreamBinderConfiguration required a single bean, but 2 were found:

• kafkaBinderConfigurationProperties: defined by method ‘kafkaBinderConfigurationProperties’ in org.springframework.cloud.stream.binder.kafka.streams.MutliBinderPropertiesConfiguration
• binderConfigurationProperties: defined by method ‘binderConfigurationProperties’ in class path resource [org/springframework/cloud/stream/binder/kafka/streams/KafkaStreamsBinderSupportAutoConfiguration.class]

Other than the above, nothing is added to this project. (No application.properties either.)

[sobychacko]

There was a regression we found out in the latest Kafka Streams binder (3.0.1.RELEASE). Can you please downgrade the version of spring-cloud-stream-binder-Kafka-streams to 3.0.0.RELEASE (need to set this version in the maven pom). We already fixed it on the latest snapshot (3.0.2.BUILD-SNAPSHOT) and will be part of the next release. There is a workaround you can try on the current release, but if you can go back to the previous version, that is easier.

[amanzag]

I just reproduced this with 3.0.3, is it supposed to be fixed?