How to load external config from s3 bucket in grails 2.5.1?

Question

In Grails 3.1.4, there is a method to load external yml file as inputstream as

 S3Service s3Service = new RestS3Service(awsCredentials)
 S3Object downloadedObject= S3Service.getObject("bucketName","application.yml")
 Resource resourceConfig = new InputStreamResource(downloadedObject.getDataInputStream())
 YamlPropertiesFactoryBean ypfb = new YamlPropertiesFactoryBean()
 ypfb.setResources(resourceConfig)
 ypfb.afterPropertiesSet()

I want to do the same in grails 2.5.1 but could not figure out. I don't want to download the file to local and set path to grails.config.location.