Add enterprise mode and refactor license check (#51864)

Add enterprise operation mode to properly map enterprise license.

Aslo refactor XPackLicenstate class to consolidate license status and mode checks.
This class has many sychronised methods to check basically three things:
* Minimum operation mode required
* Whether security is enabled
* Whether current license needs to be active

Depends on the actual feature, either 1, 2 or all of above checks are performed. 
These are now consolidated in to 3 helper methods (2 of them are new).
The synchronization is pushed down to the helper methods so actual checking
methods no longer need to worry about it.

resolves: #51081

Author: ywangd

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/CcrLicenseChecker.java

@@ -412,7 +412,7 @@ private static ElasticsearchStatusException indexMetadataNonCompliantRemoteLicen
                 RemoteClusterLicenseChecker.buildErrorMessage(
                         "ccr",
                         licenseCheck.remoteClusterLicenseInfo(),
-                        RemoteClusterLicenseChecker::isLicensePlatinumOrTrial));
+                        RemoteClusterLicenseChecker::isAllowedByLicense));
         return new ElasticsearchStatusException(message, RestStatus.BAD_REQUEST);
     }
 
@@ -426,7 +426,7 @@ private static ElasticsearchStatusException clusterStateNonCompliantRemoteLicens
                 RemoteClusterLicenseChecker.buildErrorMessage(
                         "ccr",
                         licenseCheck.remoteClusterLicenseInfo(),
-                        RemoteClusterLicenseChecker::isLicensePlatinumOrTrial));
+                        RemoteClusterLicenseChecker::isAllowedByLicense));
         return new ElasticsearchStatusException(message, RestStatus.BAD_REQUEST);
     }
 

x-pack/plugin/core/src/main/java/org/elasticsearch/license/License.java

@@ -175,7 +175,8 @@ public enum OperationMode {
         BASIC((byte) 2),
         STANDARD((byte) 3),
         GOLD((byte) 4),
-        PLATINUM((byte) 5);
+        PLATINUM((byte) 5),
+        ENTERPRISE((byte) 6);
 
         private final byte id;
 
@@ -208,8 +209,9 @@ public static OperationMode resolve(LicenseType type) {
                 case GOLD:
                     return GOLD;
                 case PLATINUM:
-                case ENTERPRISE: // TODO Add an explicit enterprise operating mode
                     return PLATINUM;
+                case ENTERPRISE:
+                    return ENTERPRISE;
                 case TRIAL:
                     return TRIAL;
                 default:

x-pack/plugin/core/src/main/java/org/elasticsearch/license/LicenseService.java

@@ -256,6 +256,7 @@ && isProductionMode(settings, clusterService.localNode())) {
                         "] license unless TLS is configured or security is disabled");
                 } else if (XPackSettings.FIPS_MODE_ENABLED.get(settings)
                     && newLicense.operationMode() != License.OperationMode.PLATINUM
+                    && newLicense.operationMode() != License.OperationMode.ENTERPRISE
                     && newLicense.operationMode() != License.OperationMode.TRIAL) {
                     throw new IllegalStateException("Cannot install a [" + newLicense.operationMode() +
                         "] license unless FIPS mode is disabled");

x-pack/plugin/core/src/main/java/org/elasticsearch/license/RemoteClusterLicenseChecker.java

@@ -138,9 +138,9 @@ public RemoteClusterLicenseChecker(final Client client, final Predicate<License.
         this.predicate = predicate;
     }
 
-    public static boolean isLicensePlatinumOrTrial(final XPackInfoResponse.LicenseInfo licenseInfo) {
+    public static boolean isAllowedByLicense(final XPackInfoResponse.LicenseInfo licenseInfo) {
         final License.OperationMode mode = License.OperationMode.parse(licenseInfo.getMode());
-        return mode == License.OperationMode.PLATINUM || mode == License.OperationMode.TRIAL;
+        return XPackLicenseState.isAllowedByOperationMode(mode, License.OperationMode.PLATINUM, true);
     }
 
     /**