AbstractReactiveMongoConfiguration seems related to spring boot trying mongodb at 127.0.0.1

I am testing a webflux application with spring-boot-starter-data-mongodb-reactive, and used AbstractReactiveMongoConfiguration to setup custom mongodb converters as explained in https://docs.spring.io/spring-data/mongodb/docs/current/reference/html/#mongo.custom-converters.xml.

Using docker, I get monitor exceptions and connection errors:

First attempt: demo_1 | 2021-10-27 06:09:07.032 INFO 1 --- [ main] org.mongodb.driver.cluster : Cluster created with settings {hosts=[127.0.0.1:27017], mode=SINGLE, requiredClusterType=UNKNOWN, serverSelectionTimeout='30000 ms'} demo_1 | 2021-10-27 06:09:07.098 INFO 1 --- [127.0.0.1:27017] org.mongodb.driver.cluster : Exception in monitor thread while connecting to server 127.0.0.1:27017

Second attempt with the right configuration: demo_1 | 2021-10-27 06:09:09.952 INFO 1 --- [ main] org.mongodb.driver.cluster : Cluster created with settings {hosts=[mongodb:27017], mode=SINGLE, requiredClusterType=UNKNOWN, serverSelectionTimeout='30000 ms'}

Failed query request: demo_1 | 2021-10-27 06:11:57.982 INFO 1 --- [or-http-epoll-2] org.mongodb.driver.cluster : No server chosen by com.mongodb.reactivestreams.client.internal.ClientSessionHelper$$Lambda$1458/0x000000080130dc30@63c1fe3e from cluster description ClusterDescription{type=UNKNOWN, connectionMode=SINGLE, serverDescriptions=[ServerDescription{address=127.0.0.1:27017, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketOpenException: Exception opening socket}, caused by {java.net.ConnectException: Connection refused}}]}. Waiting for 30000 ms before timing out

If I remove the AbstractReactiveMongoConfiguration, and configured converters with:

   @Bean
    public MongoCustomConversions mongoCustomConversions() {

        return new MongoCustomConversions(
            Arrays.asList(...);
    }

The spring-boot app no longer tries 127.0.0.1. Is it the wrong choice to use AbstractReactiveMongoConfiguration with spring-boot-starter-data-mongodb-reactive?

[mp911de]

Using AbstractReactiveMongoConfiguration defines MongoDB infrastructure beans that let Spring Boot back off from bean creation and therefore, Spring Boot properties are no longer applicable. If you want to define MongoCustomConversions within a Spring Boot application, then just define the custom conversions bean without subclassing AbstractReactiveMongoConfiguration.

[quanghuongg]

I am facing the same issue here. @Bean public MongoClient mongoClient() { ConnectionString connectionString = new ConnectionString(“”); MongoClientSettings mongoClientSettings = MongoClientSettings.builder() .applyConnectionString(connectionString) .build(); return MongoClients.create(mongoClientSettings); }