feat: make it possible to compute configuration solely from class

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

@@ -3,8 +3,10 @@
 import java.lang.annotation.Annotation;
 import java.time.Duration;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.function.Function;
@@ -19,7 +21,7 @@
 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.api.reconciler.dependent.managed.AnnotationDependentResourceConfigurator;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.managed.DependentResourceConfigurator;
 import io.javaoperatorsdk.operator.processing.dependent.workflow.Condition;
 import io.javaoperatorsdk.operator.processing.event.rate.RateLimiter;
 import io.javaoperatorsdk.operator.processing.event.source.controller.ResourceEventFilter;
@@ -112,19 +114,17 @@ public ResourceEventFilter<P> getEventFilter() {
     Class<ResourceEventFilter<P>>[] filterTypes =
         (Class<ResourceEventFilter<P>>[]) valueOrDefault(annotation,
             ControllerConfiguration::eventFilters, new Object[] {});
-    if (filterTypes.length > 0) {
-      for (var filterType : filterTypes) {
-        try {
-          ResourceEventFilter<P> filter = filterType.getConstructor().newInstance();
-
-          if (answer == null) {
-            answer = filter;
-          } else {
-            answer = answer.and(filter);
-          }
-        } catch (Exception e) {
-          throw new IllegalArgumentException(e);
+    for (var filterType : filterTypes) {
+      try {
+        ResourceEventFilter<P> filter = filterType.getConstructor().newInstance();
+
+        if (answer == null) {
+          answer = filter;
+        } else {
+          answer = answer.and(filter);
         }
+      } catch (Exception e) {
+        throw new IllegalArgumentException(e);
       }
     }
     return answer != null ? answer : ResourceEventFilters.passthrough();
@@ -168,18 +168,42 @@ private void configureFromAnnotatedReconciler(Object instance) {
     }
   }
 
+  private final Map<Class, ConfigurationConverter> converters = new HashMap<>();
+
   @SuppressWarnings("unchecked")
-  private void configureFromCustomAnnotation(Object instance) {
-    if (instance instanceof AnnotationDependentResourceConfigurator) {
-      AnnotationDependentResourceConfigurator configurator =
-          (AnnotationDependentResourceConfigurator) instance;
-      final Class<? extends Annotation> configurationClass =
-          (Class<? extends Annotation>) Utils.getFirstTypeArgumentFromInterface(
-              instance.getClass(), AnnotationDependentResourceConfigurator.class);
-      final var configAnnotation = instance.getClass().getAnnotation(configurationClass);
-      // always called even if the annotation is null so that implementations can provide default
-      // values
-      final var config = configurator.configFrom(configAnnotation, this);
+  private void configureFromCustomAnnotation(DependentResource instance) {
+    if (instance instanceof DependentResourceConfigurator) {
+      final var configurator = (DependentResourceConfigurator) instance;
+
+      // find Configured-annotated class if it exists
+      final Class<? extends DependentResource> drClass = instance.getClass();
+      Class<?> currentClass = drClass;
+      Configured configured = null;
+      while (!Object.class.equals(currentClass)) {
+        configured = currentClass.getAnnotation(Configured.class);
+        if (configured != null) {
+          break;
+        }
+        currentClass = currentClass.getSuperclass();
+      }
+
+      if (configured == null) {
+        return;
+      }
+
+      // find the associated configuration annotation
+      final var configAnnotation = drClass.getAnnotation(configured.by());
+      // and associated converter
+      var converter = converters.get(drClass);
+      if (converter == null) {
+        converter = Utils.instantiate(configured.converter(),
+            ConfigurationConverter.class,
+            Utils.contextFor(this, drClass, Configured.class));
+        converters.put(drClass, converter);
+      }
+      // always call the converter even if the annotation is not present so that default values can
+      // be provided
+      final var config = converter.configFrom(configAnnotation, this, drClass);
       configurator.configureWith(config);
     }
   }

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

@@ -0,0 +1,11 @@
+package io.javaoperatorsdk.operator.api.config;
+
+import java.lang.annotation.Annotation;
+
+import io.javaoperatorsdk.operator.api.reconciler.dependent.managed.DependentResourceConfigurator;
+
+public interface ConfigurationConverter<A extends Annotation, C, D extends DependentResourceConfigurator<? extends C>> {
+
+  C configFrom(A configAnnotation, ControllerConfiguration<?> parentConfiguration,
+      Class<D> originatingClass);
+}

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

@@ -0,0 +1,16 @@
+package io.javaoperatorsdk.operator.api.config;
+
+import java.lang.annotation.Annotation;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Configured {
+
+  Class<? extends Annotation> by();
+
+  Class<?> with();
+
+  @SuppressWarnings("rawtypes")
+  Class<? extends ConfigurationConverter> converter();
+}

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/kubernetes/KubernetesDependentConverter.java

@@ -0,0 +1,62 @@
+package io.javaoperatorsdk.operator.processing.dependent.kubernetes;
+
+import java.util.Arrays;
+import java.util.Set;
+
+import io.fabric8.kubernetes.api.model.HasMetadata;
+import io.javaoperatorsdk.operator.api.config.ConfigurationConverter;
+import io.javaoperatorsdk.operator.api.config.ControllerConfiguration;
+import io.javaoperatorsdk.operator.api.config.Utils;
+import io.javaoperatorsdk.operator.api.reconciler.Constants;
+import io.javaoperatorsdk.operator.api.reconciler.ResourceDiscriminator;
+import io.javaoperatorsdk.operator.processing.event.source.filter.GenericFilter;
+import io.javaoperatorsdk.operator.processing.event.source.filter.OnAddFilter;
+import io.javaoperatorsdk.operator.processing.event.source.filter.OnDeleteFilter;
+import io.javaoperatorsdk.operator.processing.event.source.filter.OnUpdateFilter;
+
+public class KubernetesDependentConverter<R extends HasMetadata, P extends HasMetadata> implements
+    ConfigurationConverter<KubernetesDependent, KubernetesDependentResourceConfig<R>, KubernetesDependentResource<R, P>> {
+
+
+  @Override
+  @SuppressWarnings({"unchecked", "rawtypes"})
+  public KubernetesDependentResourceConfig<R> configFrom(KubernetesDependent configAnnotation,
+      ControllerConfiguration<?> parentConfiguration,
+      Class<KubernetesDependentResource<R, P>> originatingClass) {
+    var namespaces = parentConfiguration.getNamespaces();
+    var configuredNS = false;
+    String labelSelector = null;
+    OnAddFilter<? extends HasMetadata> onAddFilter = null;
+    OnUpdateFilter<? extends HasMetadata> onUpdateFilter = null;
+    OnDeleteFilter<? extends HasMetadata> onDeleteFilter = null;
+    GenericFilter<? extends HasMetadata> genericFilter = null;
+    ResourceDiscriminator<?, ?> resourceDiscriminator = null;
+    if (configAnnotation != null) {
+      if (!Arrays.equals(KubernetesDependent.DEFAULT_NAMESPACES, configAnnotation.namespaces())) {
+        namespaces = Set.of(configAnnotation.namespaces());
+        configuredNS = true;
+      }
+
+      final var fromAnnotation = configAnnotation.labelSelector();
+      labelSelector = Constants.NO_VALUE_SET.equals(fromAnnotation) ? null : fromAnnotation;
+
+      final var context =
+          Utils.contextFor(parentConfiguration, originatingClass,
+              configAnnotation.annotationType());
+      onAddFilter = Utils.instantiate(configAnnotation.onAddFilter(), OnAddFilter.class, context);
+      onUpdateFilter =
+          Utils.instantiate(configAnnotation.onUpdateFilter(), OnUpdateFilter.class, context);
+      onDeleteFilter =
+          Utils.instantiate(configAnnotation.onDeleteFilter(), OnDeleteFilter.class, context);
+      genericFilter =
+          Utils.instantiate(configAnnotation.genericFilter(), GenericFilter.class, context);
+
+      resourceDiscriminator =
+          Utils.instantiate(configAnnotation.resourceDiscriminator(), ResourceDiscriminator.class,
+              context);
+    }
+
+    return new KubernetesDependentResourceConfig(namespaces, labelSelector, configuredNS,
+        resourceDiscriminator, onAddFilter, onUpdateFilter, onDeleteFilter, genericFilter);
+  }
+}

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/kubernetes/KubernetesDependentResource.java

@@ -1,6 +1,5 @@
 package io.javaoperatorsdk.operator.processing.dependent.kubernetes;
 
-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Optional;
 import java.util.Set;
@@ -12,35 +11,30 @@
 import io.fabric8.kubernetes.client.KubernetesClient;
 import io.fabric8.kubernetes.client.dsl.Resource;
 import io.javaoperatorsdk.operator.OperatorException;
-import io.javaoperatorsdk.operator.api.config.ControllerConfiguration;
-import io.javaoperatorsdk.operator.api.config.Utils;
+import io.javaoperatorsdk.operator.api.config.Configured;
 import io.javaoperatorsdk.operator.api.config.informer.InformerConfiguration;
 import io.javaoperatorsdk.operator.api.reconciler.Constants;
 import io.javaoperatorsdk.operator.api.reconciler.Context;
 import io.javaoperatorsdk.operator.api.reconciler.EventSourceContext;
 import io.javaoperatorsdk.operator.api.reconciler.Ignore;
-import io.javaoperatorsdk.operator.api.reconciler.ResourceDiscriminator;
 import io.javaoperatorsdk.operator.api.reconciler.dependent.GarbageCollected;
-import io.javaoperatorsdk.operator.api.reconciler.dependent.managed.AnnotationDependentResourceConfigurator;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.managed.DependentResourceConfigurator;
 import io.javaoperatorsdk.operator.api.reconciler.dependent.managed.KubernetesClientAware;
 import io.javaoperatorsdk.operator.processing.dependent.AbstractEventSourceHolderDependentResource;
 import io.javaoperatorsdk.operator.processing.dependent.Matcher;
 import io.javaoperatorsdk.operator.processing.dependent.Matcher.Result;
 import io.javaoperatorsdk.operator.processing.event.ResourceID;
 import io.javaoperatorsdk.operator.processing.event.source.SecondaryToPrimaryMapper;
-import io.javaoperatorsdk.operator.processing.event.source.filter.GenericFilter;
-import io.javaoperatorsdk.operator.processing.event.source.filter.OnAddFilter;
-import io.javaoperatorsdk.operator.processing.event.source.filter.OnDeleteFilter;
-import io.javaoperatorsdk.operator.processing.event.source.filter.OnUpdateFilter;
 import io.javaoperatorsdk.operator.processing.event.source.informer.InformerEventSource;
 import io.javaoperatorsdk.operator.processing.event.source.informer.Mappers;
 
 @Ignore
-@SuppressWarnings("rawtypes")
+@Configured(by = KubernetesDependent.class, with = KubernetesDependentResourceConfig.class,
+    converter = KubernetesDependentConverter.class)
 public abstract class KubernetesDependentResource<R extends HasMetadata, P extends HasMetadata>
     extends AbstractEventSourceHolderDependentResource<R, P, InformerEventSource<R, P>>
     implements KubernetesClientAware,
-    AnnotationDependentResourceConfigurator<KubernetesDependent, KubernetesDependentResourceConfig<R>> {
+    DependentResourceConfigurator<KubernetesDependentResourceConfig<R>> {
 
   private static final Logger log = LoggerFactory.getLogger(KubernetesDependentResource.class);
 
@@ -250,46 +244,6 @@ private void cleanupAfterEventFiltering(ResourceID resourceID) {
         .cleanupOnCreateOrUpdateEventFiltering(resourceID);
   }
 
-  @Override
-  @SuppressWarnings("unchecked")
-  public KubernetesDependentResourceConfig configFrom(KubernetesDependent kubeDependent,
-      ControllerConfiguration<?> parentConfiguration) {
-    var namespaces = parentConfiguration.getNamespaces();
-    var configuredNS = false;
-    String labelSelector = null;
-    OnAddFilter<? extends HasMetadata> onAddFilter = null;
-    OnUpdateFilter<? extends HasMetadata> onUpdateFilter = null;
-    OnDeleteFilter<? extends HasMetadata> onDeleteFilter = null;
-    GenericFilter<? extends HasMetadata> genericFilter = null;
-    ResourceDiscriminator<?, ?> resourceDiscriminator = 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 =
-          Utils.contextFor(parentConfiguration, getClass(), kubeDependent.annotationType());
-      onAddFilter = Utils.instantiate(kubeDependent.onAddFilter(), OnAddFilter.class, context);
-      onUpdateFilter =
-          Utils.instantiate(kubeDependent.onUpdateFilter(), OnUpdateFilter.class, context);
-      onDeleteFilter =
-          Utils.instantiate(kubeDependent.onDeleteFilter(), OnDeleteFilter.class, context);
-      genericFilter =
-          Utils.instantiate(kubeDependent.genericFilter(), GenericFilter.class, context);
-
-      resourceDiscriminator =
-          Utils.instantiate(kubeDependent.resourceDiscriminator(), ResourceDiscriminator.class,
-              context);
-    }
-
-    return new KubernetesDependentResourceConfig(namespaces, labelSelector, configuredNS,
-        resourceDiscriminator, onAddFilter, onUpdateFilter, onDeleteFilter, genericFilter);
-  }
-
   @Override
   public Optional<KubernetesDependentResourceConfig<R>> configuration() {
     return Optional.ofNullable(kubernetesDependentResourceConfig);

operator-framework-core/src/test/java/io/javaoperatorsdk/operator/api/config/UtilsTest.java

@@ -9,10 +9,8 @@
 import io.javaoperatorsdk.operator.api.reconciler.Reconciler;
 import io.javaoperatorsdk.operator.api.reconciler.UpdateControl;
 import io.javaoperatorsdk.operator.api.reconciler.dependent.DependentResource;
-import io.javaoperatorsdk.operator.api.reconciler.dependent.managed.AnnotationDependentResourceConfigurator;
 import io.javaoperatorsdk.operator.processing.dependent.EmptyTestDependentResource;
 import io.javaoperatorsdk.operator.processing.dependent.kubernetes.KubernetesDependentResource;
-import io.javaoperatorsdk.operator.processing.dependent.kubernetes.KubernetesDependentResourceConfig;
 import io.javaoperatorsdk.operator.sample.simple.TestCustomResource;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -96,10 +94,6 @@ void getsFirstTypeArgumentFromInterface() {
     assertThatIllegalArgumentException().isThrownBy(
         () -> Utils.getFirstTypeArgumentFromInterface(TestKubernetesDependentResource.class,
             DependentResource.class));
-
-    assertThat(Utils.getTypeArgumentFromInterfaceByIndex(TestKubernetesDependentResource.class,
-        AnnotationDependentResourceConfigurator.class, 1))
-        .isEqualTo(KubernetesDependentResourceConfig.class);
   }
 
   @Test