Remove license_mode from Licensing codebase (#93798)

The license_mode / file configuration has never been used and
represents a way to configure the license that is not compatible
with future plans. This commit removes the unused functionality.

Author: jakelandis

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

@@ -93,7 +93,7 @@ static LicenseType resolve(String name) {
                 case "basic" -> BASIC;
                 case "standard" -> STANDARD;
                 case "silver", "gold" -> GOLD;
-                case "platinum", "cloud_internal", "internal" -> // bwc for 1.x subscription_type field
+                case "platinum", "internal" -> // bwc for 1.x subscription_type field
                     PLATINUM;
                 case "enterprise" -> ENTERPRISE;
                 default -> throw new IllegalArgumentException("unknown license type [" + name + "]");
@@ -358,42 +358,12 @@ public String signature() {
     }
 
     /**
-     * @return the operation mode of the license as computed from the license type or from
-     * the license mode file
+     * @return the operation mode of the license as computed from the license type
      */
     public OperationMode operationMode() {
-        synchronized (this) {
-            if (canReadOperationModeFromFile() && operationModeFileWatcher != null) {
-                return operationModeFileWatcher.getCurrentOperationMode();
-            }
-        }
         return operationMode;
     }
 
-    private boolean canReadOperationModeFromFile() {
-        return type.equals("cloud_internal");
-    }
-
-    private volatile OperationModeFileWatcher operationModeFileWatcher;
-
-    /**
-     * Sets the operation mode file watcher for the license and initializes the
-     * file watcher when the license type allows to override operation mode from file
-     */
-    public synchronized void setOperationModeFileWatcher(final OperationModeFileWatcher operationModeFileWatcher) {
-        this.operationModeFileWatcher = operationModeFileWatcher;
-        if (canReadOperationModeFromFile()) {
-            this.operationModeFileWatcher.init();
-        }
-    }
-
-    /**
-     * Removes operation mode file watcher, so unused license objects can be gc'ed
-     */
-    public synchronized void removeOperationModeFileWatcher() {
-        this.operationModeFileWatcher = null;
-    }
-
     private void validate() {
         if (issuer == null) {
             throw new IllegalStateException("issuer can not be null");

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

@@ -31,14 +31,12 @@
 import org.elasticsearch.core.Nullable;
 import org.elasticsearch.core.SuppressForbidden;
 import org.elasticsearch.core.TimeValue;
-import org.elasticsearch.env.Environment;
 import org.elasticsearch.gateway.GatewayService;
 import org.elasticsearch.protocol.xpack.XPackInfoResponse;
 import org.elasticsearch.protocol.xpack.license.LicenseStatus;
 import org.elasticsearch.protocol.xpack.license.LicensesStatus;
 import org.elasticsearch.protocol.xpack.license.PutLicenseResponse;
 import org.elasticsearch.threadpool.ThreadPool;
-import org.elasticsearch.watcher.ResourceWatcherService;
 import org.elasticsearch.xpack.core.XPackPlugin;
 import org.elasticsearch.xpack.core.XPackSettings;
 
@@ -120,11 +118,6 @@ public class LicenseService extends AbstractLifecycleComponent implements Cluste
     private final SchedulerEngine scheduler;
     private final Clock clock;
 
-    /**
-     * File watcher for operation mode changes
-     */
-    private final OperationModeFileWatcher operationModeFileWatcher;
-
     /**
      * Callbacks to notify relative to license expiry
      */
@@ -157,8 +150,6 @@ public LicenseService(
         ThreadPool threadPool,
         ClusterService clusterService,
         Clock clock,
-        Environment env,
-        ResourceWatcherService resourceWatcherService,
         XPackLicenseState licenseState
     ) {
         this.settings = settings;
@@ -167,12 +158,6 @@ public LicenseService(
         this.scheduler = new SchedulerEngine(settings, clock);
         this.licenseState = licenseState;
         this.allowedLicenseTypes = ALLOWED_LICENSE_TYPES_SETTING.get(settings);
-        this.operationModeFileWatcher = new OperationModeFileWatcher(
-            resourceWatcherService,
-            XPackPlugin.resolveConfigFile(env, "license_mode"),
-            logger,
-            () -> updateLicenseState(getLicensesMetadata())
-        );
         this.scheduler.register(this);
         populateExpirationCallbacks();
 
@@ -561,12 +546,6 @@ public void clusterChanged(ClusterChangedEvent event) {
         }
     }
 
-    private void updateLicenseState(LicensesMetadata licensesMetadata) {
-        if (licensesMetadata != null) {
-            updateLicenseState(getLicense(licensesMetadata));
-        }
-    }
-
     protected static String getExpiryWarning(long licenseExpiryDate, long currentTime) {
         final long diff = licenseExpiryDate - currentTime;
         if (LICENSE_EXPIRATION_WARNING_PERIOD.getMillis() > diff) {
@@ -622,7 +601,6 @@ private void onUpdate(final LicensesMetadata currentLicensesMetadata) {
             final License previousLicense = currentLicenseHolder.get();
             if (license.equals(previousLicense) == false) {
                 currentLicenseHolder.set(license);
-                license.setOperationModeFileWatcher(operationModeFileWatcher);
                 scheduler.add(new SchedulerEngine.Job(LICENSE_JOB, nextLicenseCheck(license)));
                 for (ExpirationCallback expirationCallback : expirationCallbacks) {
                     scheduler.add(
@@ -632,10 +610,6 @@ private void onUpdate(final LicensesMetadata currentLicensesMetadata) {
                         )
                     );
                 }
-                if (previousLicense != null) {
-                    // remove operationModeFileWatcher to gc the old license object
-                    previousLicense.removeOperationModeFileWatcher();
-                }
                 logger.info("license [{}] mode [{}] - valid", license.uid(), license.operationMode().name().toLowerCase(Locale.ROOT));
             }
             updateLicenseState(license);

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

@@ -312,9 +312,7 @@ public Collection<Object> createComponents(
         List<Object> components = new ArrayList<>();
 
         final SSLService sslService = createSSLService(environment, resourceWatcherService);
-        setLicenseService(
-            new LicenseService(settings, threadPool, clusterService, getClock(), environment, resourceWatcherService, getLicenseState())
-        );
+        setLicenseService(new LicenseService(settings, threadPool, clusterService, getClock(), getLicenseState()));
 
         setEpochMillisSupplier(threadPool::absoluteTimeInMillis);
 

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/XPackPlugin.java

@@ -20,13 +20,11 @@
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.threadpool.TestThreadPool;
 import org.elasticsearch.threadpool.ThreadPool;
-import org.elasticsearch.watcher.ResourceWatcherService;
 import org.elasticsearch.xpack.core.XPackPlugin;
 import org.elasticsearch.xpack.core.watcher.watch.ClockMock;
 import org.junit.After;
 import org.junit.Before;
 
-import java.nio.file.Path;
 import java.util.stream.Stream;
 
 import static java.util.Collections.emptySet;
@@ -38,7 +36,6 @@ public abstract class AbstractLicenseServiceTestCase extends ESTestCase {
 
     protected LicenseService licenseService;
     protected ClusterService clusterService;
-    protected ResourceWatcherService resourceWatcherService;
     protected ClockMock clock;
     protected DiscoveryNodes discoveryNodes;
     protected Environment environment;
@@ -50,7 +47,6 @@ public void init() throws Exception {
         clusterService = mock(ClusterService.class);
         clock = ClockMock.frozen();
         discoveryNodes = mock(DiscoveryNodes.class);
-        resourceWatcherService = mock(ResourceWatcherService.class);
         environment = mock(Environment.class);
         threadPool = new TestThreadPool("license-test");
     }
@@ -65,11 +61,9 @@ protected void setInitialState(License license, XPackLicenseState licenseState,
     }
 
     protected void setInitialState(License license, XPackLicenseState licenseState, Settings settings, String selfGeneratedType) {
-        Path tempDir = createTempDir();
-        when(environment.configFile()).thenReturn(tempDir);
         licenseType = selfGeneratedType;
         settings = Settings.builder().put(settings).put(LicenseService.SELF_GENERATED_LICENSE_TYPE.getKey(), licenseType).build();
-        licenseService = new LicenseService(settings, threadPool, clusterService, clock, environment, resourceWatcherService, licenseState);
+        licenseService = new LicenseService(settings, threadPool, clusterService, clock, licenseState);
         ClusterState state = mock(ClusterState.class);
         final ClusterBlocks noBlock = ClusterBlocks.builder().build();
         when(state.blocks()).thenReturn(noBlock);