val credentialsProvider = new BasicCredentialsProvider
credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials("user", "password"))

esSinkBuilder.setRestClientFactory(
restClientBuilder -> {
restClientBuilder.setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback()

{ override def customizeHttpClient(httpClientBuilder: HttpAsyncClientBuilder) = httpClientBuilder .setDefaultCredentialsProvider(credentialsProvider) }
)
}
)