The master-is-stable indicator will retrieve useful information
regarding the discovery. This will be useful even if the local
cluster state is not recovered.

We currently do not evaluate the instance-has-master indicator
if the cluster state is not recovered, but we should remove this
constraint once master-is-stable is merged
server/src/test/java/org/elasticsearch/health/HealthServiceTests.java
assertThat(component1.indicators(), contains(hasMaster));
        }
    }
    private void assertIndicatorIsUnknownStatus(HealthIndicatorResult result) {
        assertThat(result.status(), is(equalTo(UNKNOWN)));
        assertThat(
            result.summary(),
            is(oneOf(HealthService.UNKNOWN_RESULT_SUMMARY_NOT_RECOVERED, HealthService.UNKNOWN_RESULT_SUMMARY_PREFLIGHT_FAILED))
        );
    }
    public void testPreflightIndicatorFailureTriggersUnknownResults() {
        
        var hasMaster = new HealthIndicatorResult("has_master", "coordination", RED, null, null, null, null, null);
        var hasStorage = new HealthIndicatorResult("has_storage", "data", GREEN, null, null, null, null, null);
        
        var networkLatency = new HealthIndicatorResult("network_latency", "coordination", GREEN, null, null, null, null, null);
        var slowTasks = new HealthIndicatorResult("slow_task_assignment", "coordination", YELLOW, null, null, null, null, null);
        var shardsAvailable = new HealthIndicatorResult("shards_availability", "data", GREEN, null, null, null, null, null);
        var service = new HealthService(
            List.of(createMockHealthIndicatorService(hasMaster), createMockHealthIndicatorService(hasStorage)),
            List.of(
                createMockHealthIndicatorService(networkLatency),
                createMockHealthIndicatorService(slowTasks),
                createMockHealthIndicatorService(shardsAvailable)
            ),
            mockEmptyClusterService()
        );
        List<HealthComponentResult> health = service.getHealth(null, null, false);
        assertThat(health.size(), is(equalTo(2)));
        {