Fix LogsDB plugin initialisation of cluster.logsdb.enabled (#116825)

Author: salvatore-campagna

modules/data-streams/src/javaRestTest/java/org/elasticsearch/datastreams/AbstractDataStreamIT.java

@@ -45,6 +45,7 @@ public abstract class AbstractDataStreamIT extends ESRestTestCase {
         // tests such as testIgnoreDynamicBeyondLimit.
         .setting("xpack.apm_data.enabled", "false")
         .setting("xpack.otel_data.registry.enabled", "false")
+        .setting("cluster.logsdb.enabled", "false")
         .build();
     protected RestClient client;
 

x-pack/plugin/logsdb/src/main/java/org/elasticsearch/xpack/logsdb/LogsDBPlugin.java

@@ -48,6 +48,11 @@ public LogsDBPlugin(Settings settings) {
     public Collection<?> createComponents(PluginServices services) {
         licenseService.setLicenseState(XPackPlugin.getSharedLicenseState());
         var clusterSettings = services.clusterService().getClusterSettings();
+        // The `cluster.logsdb.enabled` setting is registered by this plugin, but its value may be updated by other plugins
+        // before this plugin registers its settings update consumer below. This means we might miss updates that occurred earlier.
+        // To handle this, we explicitly fetch the current `cluster.logsdb.enabled` setting value from the cluster settings
+        // and update it, ensuring we capture any prior changes.
+        logsdbIndexModeSettingsProvider.updateClusterIndexModeLogsdbEnabled(clusterSettings.get(CLUSTER_LOGSDB_ENABLED));
         clusterSettings.addSettingsUpdateConsumer(FALLBACK_SETTING, licenseService::setSyntheticSourceFallback);
         clusterSettings.addSettingsUpdateConsumer(
             CLUSTER_LOGSDB_ENABLED,