Introduce LicenseService as an interface (#94261)

LicenseService is currently a concrete class. As part of a much
larger refactoring LicenseService will be become an interface
that the existing concrete class will implement.

This commit is a pure refactoring (no functional changes)
with the following changes:

* rename LicenseService -> ClusterStateLicenseService (and matching variables)
* move the static settings and methods from the concrete class to the interface

Author: jakelandis

x-pack/plugin/core/src/internalClusterTest/java/org/elasticsearch/xpack/cluster/routing/allocation/DataTierTelemetryPlugin.java

@@ -14,7 +14,7 @@
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.license.LicenseService;
+import org.elasticsearch.license.ClusterStateLicenseService;
 import org.elasticsearch.protocol.xpack.XPackInfoRequest;
 import org.elasticsearch.protocol.xpack.XPackInfoResponse;
 import org.elasticsearch.protocol.xpack.XPackUsageRequest;
@@ -62,10 +62,10 @@ public static class DataTiersTransportXPackInfoAction extends TransportXPackInfo
         public DataTiersTransportXPackInfoAction(
             TransportService transportService,
             ActionFilters actionFilters,
-            LicenseService licenseService,
+            ClusterStateLicenseService clusterStateLicenseService,
             NodeClient client
         ) {
-            super(transportService, actionFilters, licenseService, client);
+            super(transportService, actionFilters, clusterStateLicenseService, client);
         }
 
         @Override

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

@@ -24,13 +24,13 @@
 
 public class TransportDeleteLicenseAction extends AcknowledgedTransportMasterNodeAction<DeleteLicenseRequest> {
 
-    private final LicenseService licenseService;
+    private final ClusterStateLicenseService clusterStateLicenseService;
 
     @Inject
     public TransportDeleteLicenseAction(
         TransportService transportService,
         ClusterService clusterService,
-        LicenseService licenseService,
+        ClusterStateLicenseService clusterStateLicenseService,
         ThreadPool threadPool,
         ActionFilters actionFilters,
         IndexNameExpressionResolver indexNameExpressionResolver
@@ -45,7 +45,7 @@ public TransportDeleteLicenseAction(
             indexNameExpressionResolver,
             ThreadPool.Names.MANAGEMENT
         );
-        this.licenseService = licenseService;
+        this.clusterStateLicenseService = clusterStateLicenseService;
     }
 
     @Override
@@ -60,7 +60,7 @@ protected void masterOperation(
         ClusterState state,
         final ActionListener<AcknowledgedResponse> listener
     ) throws ElasticsearchException {
-        licenseService.removeLicense(
+        clusterStateLicenseService.removeLicense(
             listener.delegateFailure(
                 (l, postStartBasicResponse) -> l.onResponse(AcknowledgedResponse.of(postStartBasicResponse.isAcknowledged()))
             )

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

@@ -56,6 +56,6 @@ protected void masterOperation(
         ClusterState state,
         final ActionListener<GetLicenseResponse> listener
     ) throws ElasticsearchException {
-        listener.onResponse(new GetLicenseResponse(LicenseService.getLicense(state.metadata())));
+        listener.onResponse(new GetLicenseResponse(ClusterStateLicenseService.getLicense(state.metadata())));
     }
 }

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

@@ -21,13 +21,13 @@
 
 public class TransportPostStartBasicAction extends TransportMasterNodeAction<PostStartBasicRequest, PostStartBasicResponse> {
 
-    private final LicenseService licenseService;
+    private final ClusterStateLicenseService clusterStateLicenseService;
 
     @Inject
     public TransportPostStartBasicAction(
         TransportService transportService,
         ClusterService clusterService,
-        LicenseService licenseService,
+        ClusterStateLicenseService clusterStateLicenseService,
         ThreadPool threadPool,
         ActionFilters actionFilters,
         IndexNameExpressionResolver indexNameExpressionResolver
@@ -43,7 +43,7 @@ public TransportPostStartBasicAction(
             PostStartBasicResponse::new,
             ThreadPool.Names.SAME
         );
-        this.licenseService = licenseService;
+        this.clusterStateLicenseService = clusterStateLicenseService;
     }
 
     @Override
@@ -53,7 +53,7 @@ protected void masterOperation(
         ClusterState state,
         ActionListener<PostStartBasicResponse> listener
     ) throws Exception {
-        licenseService.startBasicLicense(request, listener);
+        clusterStateLicenseService.startBasicLicense(request, listener);
     }
 
     @Override

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

@@ -21,13 +21,13 @@
 
 public class TransportPostStartTrialAction extends TransportMasterNodeAction<PostStartTrialRequest, PostStartTrialResponse> {
 
-    private final LicenseService licenseService;
+    private final ClusterStateLicenseService clusterStateLicenseService;
 
     @Inject
     public TransportPostStartTrialAction(
         TransportService transportService,
         ClusterService clusterService,
-        LicenseService licenseService,
+        ClusterStateLicenseService clusterStateLicenseService,
         ThreadPool threadPool,
         ActionFilters actionFilters,
         IndexNameExpressionResolver indexNameExpressionResolver
@@ -43,7 +43,7 @@ public TransportPostStartTrialAction(
             PostStartTrialResponse::new,
             ThreadPool.Names.SAME
         );
-        this.licenseService = licenseService;
+        this.clusterStateLicenseService = clusterStateLicenseService;
     }
 
     @Override
@@ -53,7 +53,7 @@ protected void masterOperation(
         ClusterState state,
         ActionListener<PostStartTrialResponse> listener
     ) throws Exception {
-        licenseService.startTrialLicense(request, listener);
+        clusterStateLicenseService.startTrialLicense(request, listener);
     }
 
     @Override

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

@@ -23,13 +23,13 @@
 
 public class TransportPutLicenseAction extends TransportMasterNodeAction<PutLicenseRequest, PutLicenseResponse> {
 
-    private final LicenseService licenseService;
+    private final ClusterStateLicenseService clusterStateLicenseService;
 
     @Inject
     public TransportPutLicenseAction(
         TransportService transportService,
         ClusterService clusterService,
-        LicenseService licenseService,
+        ClusterStateLicenseService clusterStateLicenseService,
         ThreadPool threadPool,
         ActionFilters actionFilters,
         IndexNameExpressionResolver indexNameExpressionResolver
@@ -45,7 +45,7 @@ public TransportPutLicenseAction(
             PutLicenseResponse::new,
             ThreadPool.Names.MANAGEMENT
         );
-        this.licenseService = licenseService;
+        this.clusterStateLicenseService = clusterStateLicenseService;
     }
 
     @Override
@@ -60,7 +60,7 @@ protected void masterOperation(
         ClusterState state,
         final ActionListener<PutLicenseResponse> listener
     ) throws ElasticsearchException {
-        licenseService.registerLicense(request, listener);
+        clusterStateLicenseService.registerLicense(request, listener);
     }
 
 }

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

@@ -12,11 +12,11 @@
  * are available in a running cluster. Licenses are registered through a
  * {@link org.elasticsearch.license.PutLicenseRequest}. This action is handled by the master node, which places
  * the signed license into the cluster state. Each node listens for cluster state updates via the
- * {@link org.elasticsearch.license.LicenseService}, and updates its local copy of the license when it detects
+ * {@link org.elasticsearch.license.ClusterStateLicenseService}, and updates its local copy of the license when it detects
  * changes in the cluster state.
  *
  * The logic for which features are available given the current license is handled by
  * {@link org.elasticsearch.license.XPackLicenseState}, which is updated by the
- * {@link org.elasticsearch.license.LicenseService} when the license changes.
+ * {@link org.elasticsearch.license.ClusterStateLicenseService} when the license changes.
  */
 package org.elasticsearch.license;

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

@@ -41,7 +41,7 @@
 import org.elasticsearch.index.engine.EngineFactory;
 import org.elasticsearch.index.mapper.MetadataFieldMapper;
 import org.elasticsearch.indices.recovery.RecoverySettings;
-import org.elasticsearch.license.LicenseService;
+import org.elasticsearch.license.ClusterStateLicenseService;
 import org.elasticsearch.license.LicensesMetadata;
 import org.elasticsearch.license.Licensing;
 import org.elasticsearch.license.XPackLicenseState;
@@ -156,7 +156,7 @@ public Void run() {
     // These should not be directly accessed as they cannot be overridden in tests. Please use the getters so they can be overridden.
     private static final SetOnce<XPackLicenseState> licenseState = new SetOnce<>();
     private static final SetOnce<SSLService> sslService = new SetOnce<>();
-    private static final SetOnce<LicenseService> licenseService = new SetOnce<>();
+    private static final SetOnce<ClusterStateLicenseService> licenseService = new SetOnce<>();
     private static final SetOnce<LongSupplier> epochMillisSupplier = new SetOnce<>();
 
     public XPackPlugin(final Settings settings) {
@@ -179,7 +179,7 @@ protected SSLService getSslService() {
         return getSharedSslService();
     }
 
-    protected LicenseService getLicenseService() {
+    protected ClusterStateLicenseService getLicenseService() {
         return getSharedLicenseService();
     }
 
@@ -195,8 +195,8 @@ protected void setSslService(SSLService sslService) {
         XPackPlugin.sslService.set(sslService);
     }
 
-    protected void setLicenseService(LicenseService licenseService) {
-        XPackPlugin.licenseService.set(licenseService);
+    protected void setLicenseService(ClusterStateLicenseService clusterStateLicenseService) {
+        XPackPlugin.licenseService.set(clusterStateLicenseService);
     }
 
     protected void setLicenseState(XPackLicenseState licenseState) {
@@ -215,7 +215,7 @@ public static SSLService getSharedSslService() {
         return ssl;
     }
 
-    public static LicenseService getSharedLicenseService() {
+    public static ClusterStateLicenseService getSharedLicenseService() {
         return licenseService.get();
     }
 
@@ -312,7 +312,7 @@ public Collection<Object> createComponents(
         List<Object> components = new ArrayList<>();
 
         final SSLService sslService = createSSLService(environment, resourceWatcherService);
-        setLicenseService(new LicenseService(settings, threadPool, clusterService, getClock(), getLicenseState()));
+        setLicenseService(new ClusterStateLicenseService(settings, threadPool, clusterService, getClock(), getLicenseState()));
 
         setEpochMillisSupplier(threadPool::absoluteTimeInMillis);