Spring Boot: Populate configuration bean from external YAML config file.

database.yml

database:
  host: mydbhost

DatabaseConfiguration.java

@Configuration
@PropertySource(name = "databaseConfig", value = "classpath:database.yml", factory = YamlPropertySourceFactory.class)
@ConfigurationProperties(prefix = "database")
@Getter
@Setter
public class DatabaseConfiguration {

  private String host;
}

YamlPropertySourceFactory.java

@NoArgsConstructor
public class YamlPropertySourceFactory implements PropertySourceFactory {

  @Override
  public PropertySource<?> createPropertySource(String name, EncodedResource resource) throws IOException {
    return new YamlPropertySourceLoader().load(name, resource.getResource(), null);
  }
}