Normally, wiring up a repository requires not only defining a domain object and a repository, but also activating Spring Data. Each data store comes with an annotation to activate it for repository support. In our case, that would be @EnableReactiveMongoRepositories, since we are using MongoDB's reactive drivers.
However, with Spring Boot, we don't have to lift a finger!
Why?
Because the following code, lifted from Spring Boot itself, shows how MongoDB reactive repository support is enabled:
@Configuration @ConditionalOnClass({ MongoClient.class, ReactiveMongoRepository.class }) @ConditionalOnMissingBean({ ReactiveMongoRepositoryFactoryBean.class, ReactiveMongoRepositoryConfigurationExtension.class ...