refactor: simplify handling of reused event sources

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/AnnotationControllerConfiguration.java

@@ -17,9 +17,8 @@
 import io.javaoperatorsdk.operator.OperatorException;
 import io.javaoperatorsdk.operator.ReconcilerUtils;
 import io.javaoperatorsdk.operator.api.config.dependent.DependentResourceSpec;
-import io.javaoperatorsdk.operator.api.reconciler.Constants;
+import io.javaoperatorsdk.operator.api.reconciler.*;
 import io.javaoperatorsdk.operator.api.reconciler.ControllerConfiguration;
-import io.javaoperatorsdk.operator.api.reconciler.Reconciler;
 import io.javaoperatorsdk.operator.api.reconciler.dependent.Dependent;
 import io.javaoperatorsdk.operator.api.reconciler.dependent.DependentResource;
 import io.javaoperatorsdk.operator.processing.dependent.kubernetes.KubernetesDependent;
@@ -54,9 +53,8 @@ public AnnotationControllerConfiguration(Reconciler<P> reconciler) {
     this.reconciler = reconciler;
     this.annotation = reconciler.getClass().getAnnotation(ControllerConfiguration.class);
     if (annotation == null) {
-      throw new OperatorException(
-          "Missing mandatory @" + ControllerConfiguration.class.getSimpleName() +
-              " annotation for reconciler:  " + reconciler);
+      throw new OperatorException("Missing mandatory @" + CONTROLLER_CONFIG_ANNOTATION +
+          " annotation for reconciler:  " + reconciler);
     }
   }
 
@@ -247,9 +245,11 @@ public List<DependentResourceSpec> getDependentResources() {
         final var context = "DependentResource of type '" + dependentType.getName() + "'";
         spec = new DependentResourceSpec(dependentType, config, name,
             Set.of(dependent.dependsOn()),
-            instantiateConditionIfNotDefault(dependent.readyPostcondition(), context),
-            instantiateConditionIfNotDefault(dependent.reconcilePrecondition(), context),
-            instantiateConditionIfNotDefault(dependent.deletePostcondition(), context));
+            instantiateIfNotDefault(dependent.readyPostcondition(), Condition.class, context),
+            instantiateIfNotDefault(dependent.reconcilePrecondition(), Condition.class, context),
+            instantiateIfNotDefault(dependent.deletePostcondition(), Condition.class, context),
+            Constants.NO_VALUE_SET.equals(dependent.eventSource()) ? null
+                : dependent.eventSource());
         specsMap.put(name, spec);
       }
 
@@ -258,10 +258,10 @@ public List<DependentResourceSpec> getDependentResources() {
     return specs;
   }
 
-  protected Condition<?, ?> instantiateConditionIfNotDefault(Class<? extends Condition> condition,
+  protected <T> T instantiateIfNotDefault(Class<? extends T> toInstantiate, Class<T> defaultClass,
       String context) {
-    if (condition != Condition.class) {
-      return instantiateAndConfigureIfNeeded(condition, Condition.class, context);
+    if (!defaultClass.equals(toInstantiate)) {
+      return instantiateAndConfigureIfNeeded(toInstantiate, defaultClass, context);
     }
     return null;
   }
@@ -287,17 +287,17 @@ private Object createKubernetesResourceConfig(Class<? extends DependentResource>
     OnUpdateFilter<? extends HasMetadata> onUpdateFilter = null;
     OnDeleteFilter<? extends HasMetadata> onDeleteFilter = null;
     GenericFilter<? extends HasMetadata> genericFilter = null;
+    ResourceDiscriminator<?, ? extends HasMetadata> resourceDiscriminator = null;
+    String eventSourceNameToUse = null;
     if (kubeDependent != null) {
       if (!Arrays.equals(KubernetesDependent.DEFAULT_NAMESPACES,
           kubeDependent.namespaces())) {
         namespaces = Set.of(kubeDependent.namespaces());
         configuredNS = true;
       }
-
       final var fromAnnotation = kubeDependent.labelSelector();
       labelSelector = Constants.NO_VALUE_SET.equals(fromAnnotation) ? null : fromAnnotation;
 
-
       final var context =
           KUBE_DEPENDENT_NAME + " annotation on " + dependentType.getName() + " DependentResource";
       onAddFilter = createFilter(kubeDependent.onAddFilter(), OnAddFilter.class, context)
@@ -311,10 +311,15 @@ private Object createKubernetesResourceConfig(Class<? extends DependentResource>
       genericFilter =
           createFilter(kubeDependent.genericFilter(), GenericFilter.class, context)
               .orElse(null);
+
+      resourceDiscriminator =
+          instantiateIfNotDefault(kubeDependent.resourceDiscriminator(),
+              ResourceDiscriminator.class, context);
     }
 
     config =
-        new KubernetesDependentResourceConfig(namespaces, labelSelector, configuredNS, onAddFilter,
+        new KubernetesDependentResourceConfig(namespaces, labelSelector, configuredNS,
+            resourceDiscriminator, onAddFilter,
             onUpdateFilter, onDeleteFilter, genericFilter);
 
     return config;

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ControllerConfigurationOverrider.java

@@ -174,7 +174,7 @@ private void replaceConfig(String name, Object newConfig, DependentResourceSpec<
     namedDependentResourceSpecs.put(name,
         new DependentResourceSpec<>(current.getDependentResourceClass(), newConfig, name,
             current.getDependsOn(), current.getReadyCondition(), current.getReconcileCondition(),
-            current.getDeletePostCondition()));
+            current.getDeletePostCondition(), current.getEventSourceName().orElse(null)));
   }
 
   @SuppressWarnings("unchecked")
@@ -220,7 +220,8 @@ public ControllerConfiguration<R> build() {
       KubernetesDependentResourceConfig c) {
     return new DependentResourceSpec(spec.getDependentResourceClass(),
         c.setNamespaces(namespaces), name, spec.getDependsOn(), spec.getReadyCondition(),
-        spec.getReconcileCondition(), spec.getDeletePostCondition());
+        spec.getReconcileCondition(), spec.getDeletePostCondition(),
+        (String) spec.getEventSourceName().orElse(null));
   }
 
   public static <R extends HasMetadata> ControllerConfigurationOverrider<R> override(

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/dependent/DependentResourceSpec.java

@@ -23,16 +23,20 @@ public class DependentResourceSpec<T extends DependentResource<?, ?>, C> {
 
   private final Condition<?, ?> deletePostCondition;
 
+  private final String eventSourceName;
+
   public DependentResourceSpec(Class<T> dependentResourceClass, C dependentResourceConfig,
       String name, Set<String> dependsOn, Condition<?, ?> readyCondition,
-      Condition<?, ?> reconcileCondition, Condition<?, ?> deletePostCondition) {
+      Condition<?, ?> reconcileCondition, Condition<?, ?> deletePostCondition,
+      String eventSourceName) {
     this.dependentResourceClass = dependentResourceClass;
     this.dependentResourceConfig = dependentResourceConfig;
     this.name = name;
     this.dependsOn = dependsOn;
     this.readyCondition = readyCondition;
     this.reconcileCondition = reconcileCondition;
     this.deletePostCondition = deletePostCondition;
+    this.eventSourceName = eventSourceName;
   }
 
   public Class<T> getDependentResourceClass() {
@@ -89,4 +93,8 @@ public Condition getReconcileCondition() {
   public Condition getDeletePostCondition() {
     return deletePostCondition;
   }
+
+  public Optional<String> getEventSourceName() {
+    return Optional.ofNullable(eventSourceName);
+  }
 }

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/reconciler/Context.java

@@ -6,20 +6,27 @@
 import io.fabric8.kubernetes.api.model.HasMetadata;
 import io.javaoperatorsdk.operator.api.config.ControllerConfiguration;
 import io.javaoperatorsdk.operator.api.reconciler.dependent.managed.ManagedDependentResourceContext;
+import io.javaoperatorsdk.operator.processing.event.EventSourceRetriever;
 
 public interface Context<P extends HasMetadata> {
 
   Optional<RetryInfo> getRetryInfo();
 
-  default <T> Optional<T> getSecondaryResource(Class<T> expectedType) {
-    return getSecondaryResource(expectedType, null);
+  default <R> Optional<R> getSecondaryResource(Class<R> expectedType) {
+    return getSecondaryResource(expectedType, (String) null);
   }
 
-  <T> Set<T> getSecondaryResources(Class<T> expectedType);
+  <R> Set<R> getSecondaryResources(Class<R> expectedType);
 
-  <T> Optional<T> getSecondaryResource(Class<T> expectedType, String eventSourceName);
+  @Deprecated(forRemoval = true)
+  <R> Optional<R> getSecondaryResource(Class<R> expectedType, String eventSourceName);
+
+  <R> Optional<R> getSecondaryResource(Class<R> expectedType,
+      ResourceDiscriminator<R, P> discriminator);
 
   ControllerConfiguration<P> getControllerConfiguration();
 
   ManagedDependentResourceContext managedDependentResourceContext();
+
+  EventSourceRetriever<P> eventSourceRetriever();
 }

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/reconciler/DefaultContext.java

@@ -9,6 +9,7 @@
 import io.javaoperatorsdk.operator.api.reconciler.dependent.managed.DefaultManagedDependentResourceContext;
 import io.javaoperatorsdk.operator.api.reconciler.dependent.managed.ManagedDependentResourceContext;
 import io.javaoperatorsdk.operator.processing.Controller;
+import io.javaoperatorsdk.operator.processing.event.EventSourceRetriever;
 
 public class DefaultContext<P extends HasMetadata> implements Context<P> {
 
@@ -47,6 +48,12 @@ public <T> Optional<T> getSecondaryResource(Class<T> expectedType, String eventS
         .getSecondaryResource(primaryResource);
   }
 
+  @Override
+  public <R> Optional<R> getSecondaryResource(Class<R> expectedType,
+      ResourceDiscriminator<R, P> discriminator) {
+    return discriminator.distinguish(expectedType, primaryResource, this);
+  }
+
   @Override
   public ControllerConfiguration<P> getControllerConfiguration() {
     return controllerConfiguration;
@@ -57,6 +64,11 @@ public ManagedDependentResourceContext managedDependentResourceContext() {
     return defaultManagedDependentResourceContext;
   }
 
+  @Override
+  public EventSourceRetriever<P> eventSourceRetriever() {
+    return controller.getEventSourceManager();
+  }
+
   public DefaultContext<P> setRetryInfo(RetryInfo retryInfo) {
     this.retryInfo = retryInfo;
     return this;

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/reconciler/EventSourceContext.java

@@ -3,6 +3,8 @@
 import io.fabric8.kubernetes.api.model.HasMetadata;
 import io.fabric8.kubernetes.client.KubernetesClient;
 import io.javaoperatorsdk.operator.api.config.ControllerConfiguration;
+import io.javaoperatorsdk.operator.processing.event.EventSourceManager;
+import io.javaoperatorsdk.operator.processing.event.EventSourceRetriever;
 import io.javaoperatorsdk.operator.processing.event.source.EventSource;
 import io.javaoperatorsdk.operator.processing.event.source.IndexerResourceCache;
 
@@ -13,14 +15,14 @@
  */
 public class EventSourceContext<P extends HasMetadata> {
 
-  private final IndexerResourceCache<P> primaryCache;
+  private final EventSourceManager<P> eventSourceManager;
   private final ControllerConfiguration<P> controllerConfiguration;
   private final KubernetesClient client;
 
-  public EventSourceContext(IndexerResourceCache<P> primaryCache,
+  public EventSourceContext(EventSourceManager<P> eventSourceManager,
       ControllerConfiguration<P> controllerConfiguration,
       KubernetesClient client) {
-    this.primaryCache = primaryCache;
+    this.eventSourceManager = eventSourceManager;
     this.controllerConfiguration = controllerConfiguration;
     this.client = client;
   }
@@ -31,7 +33,7 @@ public EventSourceContext(IndexerResourceCache<P> primaryCache,
    * @return the primary resource cache
    */
   public IndexerResourceCache<P> getPrimaryCache() {
-    return primaryCache;
+    return eventSourceManager.getControllerResourceEventSource();
   }
 
   /**
@@ -54,4 +56,8 @@ public ControllerConfiguration<P> getControllerConfiguration() {
   public KubernetesClient getClient() {
     return client;
   }
+
+  public EventSourceRetriever<P> getEventSourceRetriever() {
+    return eventSourceManager;
+  }
 }

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/reconciler/EventSourceInitializer.java

@@ -1,9 +1,13 @@
 package io.javaoperatorsdk.operator.api.reconciler;
 
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
 import io.fabric8.kubernetes.api.model.HasMetadata;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.DependentResource;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.EventSourceAware;
 import io.javaoperatorsdk.operator.processing.event.source.EventSource;
 
 /**
@@ -39,6 +43,21 @@ static Map<String, EventSource> nameEventSources(EventSource... eventSources) {
     return eventSourceMap;
   }
 
+  @SuppressWarnings("unchecked,rawtypes")
+  static <K extends HasMetadata> Map<String, EventSource> nameEventSourcesFromDependentResource(
+      EventSourceContext<K> context, DependentResource... dependentResources) {
+    if (dependentResources != null) {
+      Map<String, EventSource> eventSourceMap = new HashMap<>(dependentResources.length);
+      Arrays.stream(dependentResources)
+          .filter(EventSourceAware.class::isInstance)
+          .forEach(esa -> ((EventSourceAware<?, K>) esa).eventSource(context)
+              .ifPresent(es -> eventSourceMap.put(generateNameFor(es), es)));
+      return eventSourceMap;
+    } else {
+      return Collections.emptyMap();
+    }
+  }
+
   /**
    * This is for the use case when the event sources are not access explicitly by name in the
    * reconciler.

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/reconciler/ResourceDiscriminator.java

@@ -0,0 +1,11 @@
+package io.javaoperatorsdk.operator.api.reconciler;
+
+import java.util.Optional;
+
+import io.fabric8.kubernetes.api.model.HasMetadata;
+
+public interface ResourceDiscriminator<R, P extends HasMetadata> {
+
+  Optional<R> distinguish(Class<R> resource, P primary, Context<P> context);
+
+}

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/reconciler/ResourceIDMatcherDiscriminator.java

@@ -0,0 +1,25 @@
+package io.javaoperatorsdk.operator.api.reconciler;
+
+import java.util.Optional;
+import java.util.function.Function;
+
+import io.fabric8.kubernetes.api.model.HasMetadata;
+import io.javaoperatorsdk.operator.processing.event.ResourceID;
+
+public class ResourceIDMatcherDiscriminator<R extends HasMetadata, P extends HasMetadata>
+    implements ResourceDiscriminator<R, P> {
+
+  private final Function<P, ResourceID> mapper;
+
+  public ResourceIDMatcherDiscriminator(Function<P, ResourceID> mapper) {
+    this.mapper = mapper;
+  }
+
+  @Override
+  public Optional<R> distinguish(Class<R> resource, P primary, Context<P> context) {
+    var resourceID = mapper.apply(primary);
+    return context.getSecondaryResources(resource).stream()
+        .filter(resourceID::isSameResource)
+        .findFirst();
+  }
+}

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/reconciler/dependent/Dependent.java

@@ -57,4 +57,13 @@
    *         one can be
    */
   String[] dependsOn() default {};
+
+  /**
+   * Setting here a name of the event source means that dependent resource will use an event source
+   * registered with that name. So won't create one. This is helpful if more dependent resources
+   * created for the same type, and want to share a common event source.
+   *
+   * @return event source name (if any) provided by the dependent resource should be used.
+   */
+  String eventSource() default NO_VALUE_SET;
 }

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/reconciler/dependent/DependentResource.java

@@ -1,16 +1,17 @@
 package io.javaoperatorsdk.operator.api.reconciler.dependent;
 
+import java.util.Optional;
+
 import io.fabric8.kubernetes.api.model.HasMetadata;
 import io.javaoperatorsdk.operator.api.reconciler.Context;
-import io.javaoperatorsdk.operator.processing.ResourceOwner;
 
 /**
  * An interface to implement and provide dependent resource support.
  *
  * @param <R> the dependent resource type
  * @param <P> the associated primary resource type
  */
-public interface DependentResource<R, P extends HasMetadata> extends ResourceOwner<R, P> {
+public interface DependentResource<R, P extends HasMetadata> {
 
   /**
    * Reconciles the dependent resource given the desired primary state
@@ -21,6 +22,17 @@ public interface DependentResource<R, P extends HasMetadata> extends ResourceOwn
    */
   ReconcileResult<R> reconcile(P primary, Context<P> context);
 
+  /**
+   * Retrieves the resource type associated with this DependentResource
+   *
+   * @return the resource type associated with this DependentResource
+   */
+  Class<R> resourceType();
+
+  default Optional<R> getSecondaryResource(P primary, Context<P> context) {
+    return Optional.empty();
+  }
+
   /**
    * Computes a default name for the specified DependentResource class
    *