I had noticed that in many other questions people are trying to use Elasticsearch test framework to setup integration tests with REST client (either high or low level).
I had manage to configure it without any external dependecies (maven or gradle elasticsearch plugin). This has it prons and cons, but allows to setup a real test case against a cluster and validate the responses.
You can find a working snippet here: https://gist.github.com/jmnarloch/68ab1ce0535733a65a1b293f7cd99886
Use the class as base for your tests.
You need to add as your project dependencies:
I would be cool though if this would be part of the test framework as well.