Migrate SpecificMasterNodesIT to Zen2 (#37532)

1. testSimpleOnlyMasterNodeElection - requires cluster bootstrap when
the first master node is started.
2. testElectOnlyBetweenMasterNodes - requires cluster bootstrap when
the first master node is started and requires adding voting exclusion
before shutting down the first master node.
3. testAliasFilterValidation - requires cluster bootstrap when the
first master node is started.

server/src/test/java/org/elasticsearch/cluster/SpecificMasterNodesIT.java

@@ -20,6 +20,9 @@
 package org.elasticsearch.cluster;
 
 import org.apache.lucene.search.join.ScoreMode;
+import org.elasticsearch.action.admin.cluster.configuration.AddVotingConfigExclusionsAction;
+import org.elasticsearch.action.admin.cluster.configuration.AddVotingConfigExclusionsRequest;
+import org.elasticsearch.cluster.coordination.ClusterBootstrapService;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.discovery.MasterNotDiscoveredException;
@@ -28,10 +31,12 @@
 import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.test.ESIntegTestCase.ClusterScope;
 import org.elasticsearch.test.ESIntegTestCase.Scope;
-import org.elasticsearch.test.discovery.TestZenDiscovery;
 import org.elasticsearch.test.junit.annotations.TestLogging;
 
 import java.io.IOException;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.ExecutionException;
 
 import static org.elasticsearch.discovery.zen.ElectMasterService.DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
@@ -45,10 +50,22 @@ public class SpecificMasterNodesIT extends ESIntegTestCase {
     @Override
     protected Settings nodeSettings(int nodeOrdinal) {
         return Settings.builder().put(super.nodeSettings(nodeOrdinal))
-            .put(TestZenDiscovery.USE_ZEN2.getKey(), false) // does unsafe things
             .put(DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING.getKey(), 1).build();
     }
 
+    @Override
+    protected List<Settings> addExtraClusterBootstrapSettings(List<Settings> allNodesSettings) {
+        // if it's the first master in the cluster bootstrap the cluster with this node name
+        Settings settings = allNodesSettings.get(0);
+        if (internalCluster().numMasterNodes() == 0 && settings.getAsBoolean(Node.NODE_MASTER_SETTING.getKey(), false)) {
+            return Collections.singletonList(Settings.builder()
+                    .put(settings)
+                    .put(ClusterBootstrapService.INITIAL_MASTER_NODES_SETTING.getKey(), settings.get(Node.NODE_NAME_SETTING.getKey()))
+                    .build());
+        }
+        return allNodesSettings;
+    }
+
     public void testSimpleOnlyMasterNodeElection() throws IOException {
         logger.info("--> start data node / non master node");
         internalCluster().startNode(Settings.builder().put(Node.NODE_DATA_SETTING.getKey(), true)
@@ -89,7 +106,7 @@ public void testSimpleOnlyMasterNodeElection() throws IOException {
             .execute().actionGet().getState().nodes().getMasterNode().getName(), equalTo(nextMasterEligibleNodeName));
     }
 
-    public void testElectOnlyBetweenMasterNodes() throws IOException {
+    public void testElectOnlyBetweenMasterNodes() throws IOException, ExecutionException, InterruptedException {
         logger.info("--> start data node / non master node");
         internalCluster().startNode(Settings.builder().put(Node.NODE_DATA_SETTING.getKey(), true)
             .put(Node.NODE_MASTER_SETTING.getKey(), false).put("discovery.initial_state_timeout", "1s"));
@@ -119,14 +136,16 @@ public void testElectOnlyBetweenMasterNodes() throws IOException {
             .execute().actionGet().getState().nodes().getMasterNode().getName(), equalTo(masterNodeName));
 
         logger.info("--> closing master node (1)");
+        client().execute(AddVotingConfigExclusionsAction.INSTANCE,
+                new AddVotingConfigExclusionsRequest(new String[]{masterNodeName})).get();
         internalCluster().stopCurrentMasterNode();
         assertThat(internalCluster().nonMasterClient().admin().cluster().prepareState()
             .execute().actionGet().getState().nodes().getMasterNode().getName(), equalTo(nextMasterEligableNodeName));
         assertThat(internalCluster().masterClient().admin().cluster().prepareState()
             .execute().actionGet().getState().nodes().getMasterNode().getName(), equalTo(nextMasterEligableNodeName));
     }
 
-    public void testAliasFilterValidation() throws Exception {
+    public void testAliasFilterValidation() {
         logger.info("--> start master node / non data");
         internalCluster().startNode(Settings.builder()
             .put(Node.NODE_DATA_SETTING.getKey(), false).put(Node.NODE_MASTER_SETTING.getKey(), true));