Add actuator health check support for Elasticsearch REST Clients

[anthony-foulfoin]

Hi,

Spring Boot 2.1 add auto-configurations for ElasticSearch RestClient and RestHighLevelClient.
It works well, but there is no actuator health check for the ES Rest clients.

There are two existing HealthIndicator for ES:

• ElasticsearchHealthIndicator: it works only with the tcp client, not the rest one
• ElasticsearchJestHealthIndicator: it works only with the Jest client

A solution would be to add an ElasticsearchRestHealthIndicator or to make the existing ElasticsearchHealthIndicator work with both tcp and rest clients.

For now, I use my own implementation:

@Component
public class ElasticsearchHealthIndicator extends AbstractHealthIndicator {

	@Autowired
	private RestHighLevelClient client;

	@Override
	protected void doHealthCheck(Health.Builder builder) throws IOException {
		ClusterHealthResponse response = client.cluster().health(new ClusterHealthRequest(), RequestOptions.DEFAULT);

		switch (response.getStatus()) {
			case GREEN:
			case YELLOW:
				builder.up();
				break;
			case RED:
			default:
				builder.down();
				break;
		}
	}
}

[nishantraut]

How is this enhancement planned to implement? Planning to add ElasticsearchRestHealthIndicator similar to ElasticsearchHealthIndicator using RestHighLevelClient, can someone give me pointers would like to raise PR.

[mbhave]

Thanks for offering to help, @nishantraut although it looks like we've received a PR for this issue.