Don't start a new node in InternalTestCluster#getClient (#127318)

This method would default to starting a new node when the cluster was
empty. This is pretty trappy as `getClient()` (or things like
`getMaster()` that depend on `getClient()`) don't look at all like
something that would start a new node.

In any case, the intention of tests is much clearer when they explicitly
define a cluster configuration.

Author: nielsbauman

modules/data-streams/src/internalClusterTest/java/org/elasticsearch/datastreams/IngestFailureStoreMetricsIT.java

@@ -57,7 +57,7 @@
 /**
  * An integration test that verifies how different paths/scenarios affect the APM metrics for failure stores.
  */
-@ESIntegTestCase.ClusterScope(numDataNodes = 0, numClientNodes = 0, scope = ESIntegTestCase.Scope.SUITE)
+@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 1, numClientNodes = 0, supportsDedicatedMasters = false)
 public class IngestFailureStoreMetricsIT extends ESIntegTestCase {
 
     private static final List<String> METRICS = List.of(

qa/smoke-test-http/src/internalClusterTest/java/org/elasticsearch/http/snapshots/AbstractSnapshotRestTestCase.java

@@ -14,11 +14,9 @@
 import org.elasticsearch.http.HttpSmokeTestCase;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.snapshots.mockstore.MockRepository;
-import org.elasticsearch.test.ESIntegTestCase;
 
 import java.util.Collection;
 
-@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0, numClientNodes = 0)
 public abstract class AbstractSnapshotRestTestCase extends HttpSmokeTestCase {
 
     /**

qa/smoke-test-http/src/internalClusterTest/java/org/elasticsearch/http/snapshots/RestGetSnapshotsCancellationIT.java

@@ -17,6 +17,7 @@
 import org.elasticsearch.client.Response;
 import org.elasticsearch.snapshots.AbstractSnapshotIntegTestCase;
 import org.elasticsearch.snapshots.mockstore.MockRepository;
+import org.elasticsearch.test.ESIntegTestCase;
 
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.TimeUnit;
@@ -27,6 +28,7 @@
 import static org.elasticsearch.test.TaskAssertions.awaitTaskWithPrefix;
 import static org.hamcrest.core.IsEqual.equalTo;
 
+@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0)
 public class RestGetSnapshotsCancellationIT extends AbstractSnapshotRestTestCase {
 
     public void testGetSnapshotsCancellation() throws Exception {

qa/smoke-test-http/src/internalClusterTest/java/org/elasticsearch/http/snapshots/RestSnapshotsStatusCancellationIT.java

@@ -17,6 +17,7 @@
 import org.elasticsearch.client.Response;
 import org.elasticsearch.snapshots.AbstractSnapshotIntegTestCase;
 import org.elasticsearch.snapshots.mockstore.MockRepository;
+import org.elasticsearch.test.ESIntegTestCase;
 
 import java.util.Collection;
 import java.util.concurrent.CancellationException;
@@ -27,6 +28,7 @@
 import static org.elasticsearch.test.TaskAssertions.assertAllTasksHaveFinished;
 import static org.elasticsearch.test.TaskAssertions.awaitTaskWithPrefix;
 
+@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0)
 public class RestSnapshotsStatusCancellationIT extends AbstractSnapshotRestTestCase {
 
     public void testSnapshotStatusCancellation() throws Exception {

server/src/internalClusterTest/java/org/elasticsearch/action/admin/indices/create/AutoCreateSystemIndexIT.java

@@ -50,7 +50,6 @@
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.notNullValue;
 
-@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0)
 public class AutoCreateSystemIndexIT extends ESIntegTestCase {
 
     @Override

server/src/internalClusterTest/java/org/elasticsearch/action/admin/indices/create/CreateSystemIndicesIT.java

@@ -56,7 +56,6 @@
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.nullValue;
 
-@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0)
 public class CreateSystemIndicesIT extends ESIntegTestCase {
 
     @Before
@@ -104,7 +103,6 @@ public void testSystemIndexIsAutoCreatedViaConcreteName() {
      */
     public void testNonPrimarySystemIndexIsAutoCreatedViaConcreteName() throws Exception {
         final String nonPrimarySystemIndex = INDEX_NAME + "-2";
-        internalCluster().startNodes(1);
 
         // Trigger the creation of the system index
         indexDoc(nonPrimarySystemIndex, "1", "foo", "bar");
@@ -132,7 +130,6 @@ public void testNonPrimarySystemIndexIsAutoCreatedViaConcreteName() throws Excep
      */
     public void testNonPrimarySystemIndexCreationThrowsError() {
         final String nonPrimarySystemIndex = INDEX_NAME + "-2";
-        internalCluster().startNodes(1);
 
         // Create the system index
         IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> createIndex(nonPrimarySystemIndex));
@@ -269,8 +266,6 @@ public void testCreateSystemAliasViaComposableTemplateWithAllowsTemplates() thro
     }
 
     private void doCreateTest(Runnable runnable, String concreteIndex) {
-        internalCluster().startNodes(1);
-
         // Trigger the creation of the system index
         runnable.run();
         ensureGreen(INDEX_NAME);
@@ -293,8 +288,6 @@ private void doCreateTest(Runnable runnable, String concreteIndex) {
     }
 
     public void testConcurrentAutoCreates() throws InterruptedException {
-        internalCluster().startNodes(3);
-
         final Client client = client();
         final int count = randomIntBetween(5, 30);
         final CountDownLatch latch = new CountDownLatch(count);

server/src/internalClusterTest/java/org/elasticsearch/action/bulk/BulkProcessorClusterSettingsIT.java

@@ -51,6 +51,7 @@ public void testBulkProcessorAutoCreateRestrictions() {
     }
 
     public void testIndexWithDisabledAutoCreateIndex() {
+        internalCluster().startNode();
         updateClusterSettings(Settings.builder().put(AutoCreateIndex.AUTO_CREATE_INDEX_SETTING.getKey(), randomFrom("-*", "+.*")));
         final BulkItemResponse itemResponse = client().prepareBulk()
             .add(prepareIndex("test-index").setSource("foo", "bar"))

server/src/internalClusterTest/java/org/elasticsearch/cluster/allocation/AwarenessAllocationIT.java

@@ -251,6 +251,7 @@ public void testAwarenessZonesIncrementalNodes() {
     }
 
     public void testForceAwarenessSettingValidation() {
+        internalCluster().startNode();
         final String prefix = AwarenessAllocationDecider.CLUSTER_ROUTING_ALLOCATION_AWARENESS_FORCE_GROUP_SETTING.getKey();
 
         final IllegalArgumentException illegalArgumentException = expectThrows(

server/src/internalClusterTest/java/org/elasticsearch/cluster/allocation/FilteringAllocationIT.java

@@ -186,6 +186,8 @@ public void testDisablingAllocationFiltering() {
     }
 
     public void testInvalidIPFilterClusterSettings() {
+        logger.info("--> starting 2 nodes");
+        internalCluster().startNodes(2);
         String ipKey = randomFrom("_ip", "_host_ip", "_publish_ip");
         var filterSetting = randomFrom(
             FilterAllocationDecider.CLUSTER_ROUTING_REQUIRE_GROUP_SETTING,

server/src/internalClusterTest/java/org/elasticsearch/health/node/ShardsCapacityHealthIndicatorServiceIT.java

@@ -16,7 +16,6 @@
 import org.elasticsearch.health.HealthStatus;
 import org.elasticsearch.health.metadata.HealthMetadata;
 import org.elasticsearch.test.ESIntegTestCase;
-import org.elasticsearch.test.InternalTestCluster;
 import org.junit.After;
 import org.junit.Before;
 
@@ -27,16 +26,14 @@
 import static org.hamcrest.Matchers.empty;
 import static org.hamcrest.Matchers.hasSize;
 
-@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0)
+@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 1, numClientNodes = 0, supportsDedicatedMasters = false)
 public class ShardsCapacityHealthIndicatorServiceIT extends ESIntegTestCase {
 
     private static final String INDEX_NAME = "index-name";
-    private InternalTestCluster internalCluster;
 
     @Before
     public void setUp() throws Exception {
         super.setUp();
-        internalCluster = internalCluster();
         updateClusterSettings(Settings.builder().put(SETTING_CLUSTER_MAX_SHARDS_PER_NODE.getKey(), 30));
     }
 
@@ -53,7 +50,7 @@ public void testGreen() throws Exception {
         // index: 4 shards + 1 replica = 8 shards used (30 - 8 = 22 > 10 available shards)
         createIndex(4, 1);
 
-        var result = fetchShardsCapacityIndicatorResult(internalCluster);
+        var result = fetchShardsCapacityIndicatorResult();
         assertEquals(result.status(), HealthStatus.GREEN);
         assertEquals(result.symptom(), "The cluster has enough room to add new shards.");
         assertThat(result.diagnosisList(), empty());
@@ -64,7 +61,7 @@ public void testYellow() throws Exception {
         // index: 11 shards + 1 replica = 22 shards used (30 - 22 < 10 available shards)
         createIndex(10, 1);
 
-        var result = fetchShardsCapacityIndicatorResult(internalCluster);
+        var result = fetchShardsCapacityIndicatorResult();
         assertEquals(result.status(), HealthStatus.YELLOW);
         assertEquals(result.symptom(), "Cluster is close to reaching the configured maximum number of shards for data nodes.");
         assertThat(result.diagnosisList(), hasSize(1));
@@ -75,7 +72,7 @@ public void testRed() throws Exception {
         // index: 13 shards + 1 replica = 26 shards used (30 - 26 < 5 available shards)
         createIndex(13, 1);
 
-        var result = fetchShardsCapacityIndicatorResult(internalCluster);
+        var result = fetchShardsCapacityIndicatorResult();
         assertEquals(result.status(), HealthStatus.RED);
         assertEquals(result.symptom(), "Cluster is close to reaching the configured maximum number of shards for data nodes.");
         assertThat(result.diagnosisList(), hasSize(1));
@@ -86,15 +83,15 @@ private void createIndex(int shards, int replicas) {
         createIndex(INDEX_NAME, indexSettings(shards, replicas).build());
     }
 
-    private HealthIndicatorResult fetchShardsCapacityIndicatorResult(InternalTestCluster internalCluster) throws Exception {
-        ensureStableCluster(internalCluster.getNodeNames().length);
-        var healthNode = ESIntegTestCase.waitAndGetHealthNode(internalCluster);
+    private HealthIndicatorResult fetchShardsCapacityIndicatorResult() throws Exception {
+        ensureStableCluster(internalCluster().getNodeNames().length);
+        var healthNode = ESIntegTestCase.waitAndGetHealthNode(internalCluster());
         assertNotNull(healthNode);
 
-        var randomNode = internalCluster.getRandomNodeName();
+        var randomNode = internalCluster().getRandomNodeName();
         waitForShardLimitsMetadata(randomNode);
 
-        var healthService = internalCluster.getInstance(HealthService.class, randomNode);
+        var healthService = internalCluster().getInstance(HealthService.class, randomNode);
         var healthIndicatorResults = getHealthServiceResults(healthService, randomNode);
         assertThat(healthIndicatorResults, hasSize(1));
         return healthIndicatorResults.get(0);