fix: minor improvements (#799)

Author: csviri

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/EventSourceManager.java

@@ -40,15 +40,15 @@ public class EventSourceManager<R extends HasMetadata> implements LifecycleAware
   EventSourceManager(EventProcessor<R> eventProcessor) {
     this.eventProcessor = eventProcessor;
     controller = null;
-    registerEventSource(eventSources.initRetryEventSource());
+    registerEventSource(eventSources.retryEventSource());
   }
 
   public EventSourceManager(Controller<R> controller) {
     this.controller = controller;
     // controller event source needs to be available before we create the event processor
     final var controllerEventSource = eventSources.initControllerEventSource(controller);
     this.eventProcessor = new EventProcessor<>(this);
-    registerEventSource(eventSources.initRetryEventSource());
+    registerEventSource(eventSources.retryEventSource());
     registerEventSource(controllerEventSource);
   }
 
@@ -184,7 +184,7 @@ ControllerResourceEventSource<R> initControllerEventSource(Controller<R> control
       return controllerResourceEventSource;
     }
 
-    TimerEventSource<R> initRetryEventSource() {
+    TimerEventSource<R> retryEventSource() {
       return retryAndRescheduleTimerEventSource;
     }
 

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/controller/ResourceEventFilters.java

@@ -25,8 +25,6 @@ public final class ResourceEventFilters {
   private static final ResourceEventFilter<HasMetadata> GENERATION_AWARE =
       (configuration, oldResource, newResource) -> {
         final var generationAware = configuration.isGenerationAware();
-        // todo: change this to check for HasStatus (or similar) when
-        // https://github.com/fabric8io/kubernetes-client/issues/3586 is fixed
         if (newResource instanceof CustomResource<?, ?>) {
           var newCustomResource = (CustomResource<?, ?>) newResource;
           final var status = newCustomResource.getStatus();

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/polling/PerResourcePollingEventSource.java

@@ -97,6 +97,10 @@ public void onResourceDeleted(R resource) {
     cache.remove(resourceID);
   }
 
+  // This method is always called from the same Thread for the same resource,
+  // since events from ResourceEventAware are propagated from the thread of the informer. This is
+  // important
+  // because otherwise there will be a race condition related to the timerTasks.
   private void checkAndRegisterTask(R resource) {
     var resourceID = ResourceID.fromResource(resource);
     if (timerTasks.get(resourceID) == null && (registerPredicate == null

sample-operators/mysql-schema/src/main/java/io/javaoperatorsdk/operator/sample/MySQLSchemaOperator.java

@@ -27,8 +27,10 @@ public static void main(String[] args) throws IOException {
     KubernetesClient client = new DefaultKubernetesClient(config);
     Operator operator = new Operator(client, DefaultConfigurationService.instance());
     operator.register(new MySQLSchemaReconciler(client, MySQLDbConfig.loadFromEnvironmentVars()));
+    operator.installShutdownHook();
     operator.start();
 
+
     new FtBasic(new TkFork(new FkRegex("/health", "ALL GOOD!")), 8080).start(Exit.NEVER);
   }
 }

sample-operators/tomcat-operator/src/main/java/io/javaoperatorsdk/operator/sample/TomcatOperator.java

@@ -27,6 +27,7 @@ public static void main(String[] args) throws IOException {
     Operator operator = new Operator(client, DefaultConfigurationService.instance());
     operator.register(new TomcatReconciler(client));
     operator.register(new WebappReconciler(client));
+    operator.installShutdownHook();
     operator.start();
 
     new FtBasic(new TkFork(new FkRegex("/health", "ALL GOOD.")), 8080).start(Exit.NEVER);

sample-operators/webpage/src/main/java/io/javaoperatorsdk/operator/sample/WebPageOperator.java

@@ -27,6 +27,7 @@ public static void main(String[] args) throws IOException {
     KubernetesClient client = new DefaultKubernetesClient(config);
     Operator operator = new Operator(client, DefaultConfigurationService.instance());
     operator.register(new WebPageReconciler(client));
+    operator.installShutdownHook();
     operator.start();
 
     new FtBasic(new TkFork(new FkRegex("/health", "ALL GOOD!")), 8080).start(Exit.NEVER);