[Backport 2.x] Remove Identity FeatureFlag (#16024)

CHANGELOG.md

@@ -10,7 +10,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - [Workload Management] QueryGroup resource cancellation framework changes ([#15651](https://github.com/opensearch-project/OpenSearch/pull/15651))
 - Implement WithFieldName interface in ValuesSourceAggregationBuilder & FieldSortBuilder ([#15916](https://github.com/opensearch-project/OpenSearch/pull/15916))
 - Add successfulSearchShardIndices in searchRequestContext ([#15967](https://github.com/opensearch-project/OpenSearch/pull/15967))
-- Remove identity-related feature flagged code from the RestController ([#15430](https://github.com/opensearch-project/OpenSearch/pull/15430))
 - Fallback to Remote cluster-state on Term-Version check mismatch - ([#15424](https://github.com/opensearch-project/OpenSearch/pull/15424))
 - Add support for msearch API to pass search pipeline name - ([#15923](https://github.com/opensearch-project/OpenSearch/pull/15923))
 - Add success and failure metrics for async shard fetch ([#15976](https://github.com/opensearch-project/OpenSearch/pull/15976))
@@ -33,6 +32,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ### Changed
 - Add support for docker compose v2 in TestFixturesPlugin ([#16049](https://github.com/opensearch-project/OpenSearch/pull/16049))
+- Remove identity-related feature flagged code from the RestController ([#15430](https://github.com/opensearch-project/OpenSearch/pull/15430))
+- Remove Identity FeatureFlag ([#16024](https://github.com/opensearch-project/OpenSearch/pull/16024))
 
 
 ### Deprecated

qa/smoke-test-http/src/test/java/org/opensearch/http/IdentityAuthenticationIT.java

@@ -38,7 +38,6 @@ public class IdentityAuthenticationIT extends HttpSmokeTestCase {
     protected Settings nodeSettings(int nodeOrdinal) {
         return Settings.builder()
             .put(super.nodeSettings(nodeOrdinal))
-            .put(FeatureFlags.IDENTITY, "true")
             .build();
     }
 

server/src/main/java/org/opensearch/common/settings/FeatureFlagSettings.java

@@ -31,7 +31,6 @@ protected FeatureFlagSettings(
 
     public static final Set<Setting<?>> BUILT_IN_FEATURE_FLAGS = Set.of(
         FeatureFlags.EXTENSIONS_SETTING,
-        FeatureFlags.IDENTITY_SETTING,
         FeatureFlags.TELEMETRY_SETTING,
         FeatureFlags.DATETIME_FORMATTER_CACHING_SETTING,
         FeatureFlags.TIERED_REMOTE_INDEX_SETTING,

server/src/main/java/org/opensearch/common/util/FeatureFlags.java

@@ -40,11 +40,6 @@ public class FeatureFlags {
      */
     public static final String EXTENSIONS = "opensearch.experimental.feature.extensions.enabled";
 
-    /**
-     * Gates the functionality of identity.
-     */
-    public static final String IDENTITY = "opensearch.experimental.feature.identity.enabled";
-
     /**
      * Gates the functionality of telemetry framework.
      */
@@ -82,8 +77,6 @@ public class FeatureFlags {
 
     public static final Setting<Boolean> EXTENSIONS_SETTING = Setting.boolSetting(EXTENSIONS, false, Property.NodeScope);
 
-    public static final Setting<Boolean> IDENTITY_SETTING = Setting.boolSetting(IDENTITY, false, Property.NodeScope);
-
     public static final Setting<Boolean> TELEMETRY_SETTING = Setting.boolSetting(TELEMETRY, false, Property.NodeScope);
 
     public static final Setting<Boolean> DATETIME_FORMATTER_CACHING_SETTING = Setting.boolSetting(
@@ -138,7 +131,6 @@ public class FeatureFlags {
     private static final List<Setting<Boolean>> ALL_FEATURE_FLAG_SETTINGS = List.of(
         REMOTE_STORE_MIGRATION_EXPERIMENTAL_SETTING,
         EXTENSIONS_SETTING,
-        IDENTITY_SETTING,
         TELEMETRY_SETTING,
         DATETIME_FORMATTER_CACHING_SETTING,
         TIERED_REMOTE_INDEX_SETTING,

server/src/main/java/org/opensearch/identity/IdentityService.java

@@ -8,6 +8,7 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.opensearch.OpenSearchException;
+import org.opensearch.common.annotation.InternalApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.identity.noop.NoopIdentityPlugin;
 import org.opensearch.identity.tokens.TokenManager;
@@ -22,8 +23,9 @@
 /**
  * Identity and access control for OpenSearch
  *
- * @opensearch.experimental
+ * @opensearch.internal
  * */
+@InternalApi
 public class IdentityService {
     private static final Logger log = LogManager.getLogger(IdentityService.class);
 

server/src/main/java/org/opensearch/node/Node.java

@@ -525,11 +525,7 @@ protected Node(
             FeatureFlags.initializeFeatureFlags(settings);
 
             final List<IdentityPlugin> identityPlugins = new ArrayList<>();
-            if (FeatureFlags.isEnabled(FeatureFlags.IDENTITY)) {
-                // If identity is enabled load plugins implementing the extension point
-                logger.info("Identity on so found plugins implementing: " + pluginsService.filterPlugins(IdentityPlugin.class).toString());
-                identityPlugins.addAll(pluginsService.filterPlugins(IdentityPlugin.class));
-            }
+            identityPlugins.addAll(pluginsService.filterPlugins(IdentityPlugin.class));
 
             final Set<DiscoveryNodeRole> additionalRoles = pluginsService.filterPlugins(Plugin.class)
                 .stream()

server/src/test/java/org/opensearch/common/util/FeatureFlagTests.java

@@ -14,7 +14,6 @@
 
 import static org.opensearch.common.util.FeatureFlags.DATETIME_FORMATTER_CACHING;
 import static org.opensearch.common.util.FeatureFlags.EXTENSIONS;
-import static org.opensearch.common.util.FeatureFlags.IDENTITY;
 
 public class FeatureFlagTests extends OpenSearchTestCase {
 
@@ -40,7 +39,7 @@ public void testNonBooleanFeatureFlag() {
     }
 
     public void testBooleanFeatureFlagWithDefaultSetToFalse() {
-        final String testFlag = IDENTITY;
+        final String testFlag = EXTENSIONS;
         FeatureFlags.initializeFeatureFlags(Settings.EMPTY);
         assertNotNull(testFlag);
         assertFalse(FeatureFlags.isEnabled(testFlag));
@@ -49,15 +48,13 @@ public void testBooleanFeatureFlagWithDefaultSetToFalse() {
     public void testBooleanFeatureFlagInitializedWithEmptySettingsAndDefaultSetToFalse() {
         final String testFlag = DATETIME_FORMATTER_CACHING;
         FeatureFlags.initializeFeatureFlags(Settings.EMPTY);
-        assertNotNull(testFlag);
         assertFalse(FeatureFlags.isEnabled(testFlag));
     }
 
     public void testInitializeFeatureFlagsWithExperimentalSettings() {
-        FeatureFlags.initializeFeatureFlags(Settings.builder().put(IDENTITY, true).build());
-        assertTrue(FeatureFlags.isEnabled(IDENTITY));
+        FeatureFlags.initializeFeatureFlags(Settings.builder().put(EXTENSIONS, true).build());
+        assertTrue(FeatureFlags.isEnabled(EXTENSIONS));
         assertFalse(FeatureFlags.isEnabled(DATETIME_FORMATTER_CACHING));
-        assertFalse(FeatureFlags.isEnabled(EXTENSIONS));
         // reset FeatureFlags to defaults
         FeatureFlags.initializeFeatureFlags(Settings.EMPTY);
     }