Watcher: Remove test-only setting (#34377)

In 54cb890 a setting for testing only was introduced, that delayed the start up of watcher. With the changes of how is watcher is started/stopped over time, this is not needed anymore.

Author: spinscale

x-pack/plugin/watcher/src/main/java/org/elasticsearch/xpack/watcher/Watcher.java

@@ -476,7 +476,6 @@ public List<Setting<?>> getSettings() {
         settings.add(Setting.simpleString("xpack.watcher.input.search.default_timeout", Setting.Property.NodeScope));
         settings.add(Setting.simpleString("xpack.watcher.transform.search.default_timeout", Setting.Property.NodeScope));
         settings.add(Setting.simpleString("xpack.watcher.execution.scroll.timeout", Setting.Property.NodeScope));
-        settings.add(WatcherLifeCycleService.SETTING_REQUIRE_MANUAL_START);
 
         // bulk processor configuration
         settings.add(SETTING_BULK_ACTIONS);

x-pack/plugin/watcher/src/main/java/org/elasticsearch/xpack/watcher/WatcherLifeCycleService.java

@@ -17,8 +17,6 @@
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.component.AbstractComponent;
 import org.elasticsearch.common.component.LifecycleListener;
-import org.elasticsearch.common.settings.Setting;
-import org.elasticsearch.common.settings.Setting.Property;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.gateway.GatewayService;
 import org.elasticsearch.index.shard.ShardId;
@@ -39,23 +37,14 @@
 
 public class WatcherLifeCycleService extends AbstractComponent implements ClusterStateListener {
 
-    // this option configures watcher not to start, unless the cluster state contains information to start watcher
-    // if you start with an empty cluster, you can delay starting watcher until you call the API manually
-    // if you start with a cluster containing data, this setting might have no effect, once you called the API yourself
-    // this is merely for testing, to make sure that watcher only starts when manually called
-    public static final Setting<Boolean> SETTING_REQUIRE_MANUAL_START =
-            Setting.boolSetting("xpack.watcher.require_manual_start", false, Property.NodeScope);
-
     private final AtomicReference<WatcherState> state = new AtomicReference<>(WatcherState.STARTED);
     private final AtomicReference<List<ShardRouting>> previousShardRoutings = new AtomicReference<>(Collections.emptyList());
-    private final boolean requireManualStart;
     private volatile boolean shutDown = false; // indicates that the node has been shutdown and we should never start watcher after this.
     private volatile WatcherService watcherService;
 
     WatcherLifeCycleService(Settings settings, ClusterService clusterService, WatcherService watcherService) {
         super(settings);
         this.watcherService = watcherService;
-        this.requireManualStart = SETTING_REQUIRE_MANUAL_START.get(settings);
         clusterService.addListener(this);
         // Close if the indices service is being stopped, so we don't run into search failures (locally) that will
         // happen because we're shutting down and an watch is scheduled.
@@ -91,13 +80,6 @@ public void clusterChanged(ClusterChangedEvent event) {
             return;
         }
 
-        // if watcher should not be started immediately unless it is has been manually configured to do so
-        WatcherMetaData watcherMetaData = event.state().getMetaData().custom(WatcherMetaData.TYPE);
-        if (watcherMetaData == null && requireManualStart) {
-            clearAllocationIds();
-            return;
-        }
-
         if (Strings.isNullOrEmpty(event.state().nodes().getMasterNodeId())) {
             pauseExecution("no master node");
             return;

x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/test/AbstractWatcherIntegrationTestCase.java

@@ -49,7 +49,6 @@
 import org.elasticsearch.xpack.core.watcher.transport.actions.stats.WatcherStatsResponse;
 import org.elasticsearch.xpack.core.watcher.watch.ClockMock;
 import org.elasticsearch.xpack.core.watcher.watch.Watch;
-import org.elasticsearch.xpack.watcher.WatcherLifeCycleService;
 import org.elasticsearch.xpack.watcher.history.HistoryStore;
 import org.elasticsearch.xpack.watcher.notification.email.Authentication;
 import org.elasticsearch.xpack.watcher.notification.email.Email;
@@ -111,7 +110,6 @@ protected Settings nodeSettings(int nodeOrdinal) {
                 // watcher settings that should work despite randomization
                 .put("xpack.watcher.execution.scroll.size", randomIntBetween(1, 100))
                 .put("xpack.watcher.watch.scroll.size", randomIntBetween(1, 100))
-                .put(WatcherLifeCycleService.SETTING_REQUIRE_MANUAL_START.getKey(), true)
                 .build();
     }