refactor: clean-up dependent implementation (#906)

* feat: add desired and matches methods on DependentResource

This removes the need for Builder and Updater interfaces.

* refactor: move classes to more coherent locations

* refactor: remove DependentResourceControllerFactory

* refactor: remove Cleaner interface

* refactor: put the reconciling logic in DependentResourceController

* refactor: return DependentResource.desired now returns Optional

* chore: add @ignore to mark internal Reconciler implementations

Author: metacosm

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

@@ -7,8 +7,8 @@
 
 import io.fabric8.kubernetes.api.model.HasMetadata;
 import io.javaoperatorsdk.operator.ReconcilerUtils;
+import io.javaoperatorsdk.operator.api.config.dependent.DependentResourceConfiguration;
 import io.javaoperatorsdk.operator.api.reconciler.Constants;
-import io.javaoperatorsdk.operator.api.reconciler.dependent.DependentResourceControllerFactory;
 import io.javaoperatorsdk.operator.processing.event.source.controller.ResourceEventFilter;
 import io.javaoperatorsdk.operator.processing.event.source.controller.ResourceEventFilters;
 
@@ -54,10 +54,6 @@ default List<DependentResourceConfiguration> getDependentResources() {
     return Collections.emptyList();
   }
 
-  default DependentResourceControllerFactory<R> dependentFactory() {
-    return new DependentResourceControllerFactory<>() {};
-  }
-
   default Optional<Duration> reconciliationMaxInterval() {
     return Optional.of(Duration.ofHours(10L));
   }

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

@@ -7,6 +7,7 @@
 import java.util.Set;
 
 import io.fabric8.kubernetes.api.model.HasMetadata;
+import io.javaoperatorsdk.operator.api.config.dependent.DependentResourceConfiguration;
 import io.javaoperatorsdk.operator.processing.event.source.controller.ResourceEventFilter;
 
 public class DefaultControllerConfiguration<R extends HasMetadata>

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

@@ -0,0 +1,10 @@
+package io.javaoperatorsdk.operator.api.config.dependent;
+
+import io.javaoperatorsdk.operator.api.reconciler.dependent.DependentResource;
+
+public @interface Dependent {
+
+  Class<?> resourceType();
+
+  Class<? extends DependentResource> type();
+}

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

@@ -1,6 +1,7 @@
-package io.javaoperatorsdk.operator.api.config;
+package io.javaoperatorsdk.operator.api.config.dependent;
 
 import io.fabric8.kubernetes.api.model.HasMetadata;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.DependentResource;
 
 public interface DependentResourceConfiguration<R, P extends HasMetadata> {
 

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

@@ -1,4 +1,4 @@
-package io.javaoperatorsdk.operator.api.config;
+package io.javaoperatorsdk.operator.api.config.dependent;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/DependentResourceConfiguration.java renamed to operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/dependent/DependentResourceConfiguration.java

@@ -1,14 +1,13 @@
-package io.javaoperatorsdk.operator.api.reconciler.dependent;
+package io.javaoperatorsdk.operator.api.config.dependent;
 
 import java.util.Set;
 
 import io.fabric8.kubernetes.api.model.HasMetadata;
 import io.javaoperatorsdk.operator.api.config.ConfigurationService;
-import io.javaoperatorsdk.operator.api.config.DependentResource;
-import io.javaoperatorsdk.operator.api.config.DependentResourceConfiguration;
+import io.javaoperatorsdk.operator.api.config.informer.InformerConfiguration;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.DependentResource;
 import io.javaoperatorsdk.operator.processing.event.source.AssociatedSecondaryResourceIdentifier;
 import io.javaoperatorsdk.operator.processing.event.source.PrimaryResourcesRetriever;
-import io.javaoperatorsdk.operator.processing.event.source.informer.InformerConfiguration;
 
 public interface KubernetesDependentResourceConfiguration<R extends HasMetadata, P extends HasMetadata>
     extends InformerConfiguration<R, P>, DependentResourceConfiguration<R, P> {

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/KubernetesDependent.java renamed to operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/dependent/KubernetesDependent.java

@@ -1,4 +1,4 @@
-package io.javaoperatorsdk.operator.processing.event.source.informer;
+package io.javaoperatorsdk.operator.api.config.informer;
 
 import java.util.Collections;
 import java.util.Objects;
@@ -12,6 +12,7 @@
 import io.javaoperatorsdk.operator.processing.event.ResourceID;
 import io.javaoperatorsdk.operator.processing.event.source.AssociatedSecondaryResourceIdentifier;
 import io.javaoperatorsdk.operator.processing.event.source.PrimaryResourcesRetriever;
+import io.javaoperatorsdk.operator.processing.event.source.informer.Mappers;
 
 public interface InformerConfiguration<R extends HasMetadata, P extends HasMetadata>
     extends ResourceConfiguration<R> {

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/reconciler/dependent/KubernetesDependentResourceConfiguration.java renamed to operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/dependent/KubernetesDependentResourceConfiguration.java

@@ -6,8 +6,8 @@
 import java.lang.annotation.Target;
 import java.util.concurrent.TimeUnit;
 
-import io.javaoperatorsdk.operator.api.config.Dependent;
-import io.javaoperatorsdk.operator.api.reconciler.dependent.DependentResourceController;
+import io.javaoperatorsdk.operator.api.config.dependent.Dependent;
+import io.javaoperatorsdk.operator.processing.dependent.DependentResourceController;
 import io.javaoperatorsdk.operator.processing.event.source.controller.ResourceEventFilter;
 
 @Retention(RetentionPolicy.RUNTIME)

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerConfiguration.java renamed to operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/informer/InformerConfiguration.java

@@ -0,0 +1,62 @@
+package io.javaoperatorsdk.operator.api.reconciler.dependent;
+
+import java.util.Optional;
+
+import io.fabric8.kubernetes.api.model.HasMetadata;
+import io.javaoperatorsdk.operator.api.config.Utils;
+import io.javaoperatorsdk.operator.api.reconciler.Context;
+import io.javaoperatorsdk.operator.api.reconciler.EventSourceContext;
+import io.javaoperatorsdk.operator.processing.event.source.EventSource;
+
+public interface DependentResource<R, P extends HasMetadata> {
+  default EventSource initEventSource(EventSourceContext<P> context) {
+    throw new IllegalStateException("Must be implemented if not automatically provided by the SDK");
+  }
+
+  @SuppressWarnings("unchecked")
+  default Class<R> resourceType() {
+    return (Class<R>) Utils.getFirstTypeArgumentFromInterface(getClass());
+  }
+
+  default void delete(R fetched, P primary, Context context) {}
+
+  /**
+   * Computes the desired state of the dependent based on the state provided by the specified
+   * primary resource.
+   * 
+   * The default implementation returns {@code empty} which corresponds to the case where the
+   * associated dependent should never be created by the associated reconciler or that the global
+   * state of the cluster doesn't allow for the resource to be created at this point.
+   * 
+   * @param primary the primary resource associated with the reconciliation process
+   * @param context the {@link Context} associated with the reconciliation process
+   * @return an instance of the dependent resource matching the desired state specified by the
+   *         primary resource or {@code empty} if the dependent shouldn't be created at this point
+   *         (or ever)
+   */
+  default Optional<R> desired(P primary, Context context) {
+    return Optional.empty();
+  }
+
+  /**
+   * Checks whether the actual resource as fetched from the cluster matches the desired state
+   * expressed by the specified primary resource.
+   * 
+   * The default implementation always return {@code true}, which corresponds to the behavior where
+   * the dependent never needs to be updated after it's been created.
+   * 
+   * Note that failure to properly implement this method will lead to infinite loops. In particular,
+   * for typical Kubernetes resource implementations, simply calling
+   * {@code desired(primary, context).equals(actual)} is not enough because metadata will usually be
+   * different.
+   * 
+   * @param actual the current state of the resource as fetched from the cluster
+   * @param primary the primary resource associated with the reconciliation request
+   * @param context the {@link Context} associated with the reconciliation request
+   * @return {@code true} if the actual state of the resource matches the desired state expressed by
+   *         the specified primary resource, {@code false} otherwise
+   */
+  default boolean match(R actual, P primary, Context context) {
+    return true;
+  }
+}