feat: introduce declarative support for dependent resources

Author: metacosm

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/Operator.java

@@ -34,6 +34,7 @@ public Operator(ConfigurationService configurationService) {
   public Operator(KubernetesClient kubernetesClient, ConfigurationService configurationService) {
     this.kubernetesClient = kubernetesClient;
     this.configurationService = configurationService;
+    ExecutorServiceManager.init(configurationService);
   }
 
   /** Adds a shutdown hook that automatically calls {@link #close()} when the app shuts down. */
@@ -85,7 +86,6 @@ public void start() {
       throw new OperatorException(error, e);
     }
 
-    ExecutorServiceManager.init(configurationService);
     controllers.start();
   }
 

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/ReconcilerUtils.java

@@ -2,6 +2,7 @@
 
 import java.util.Locale;
 
+import io.javaoperatorsdk.operator.api.reconciler.Constants;
 import io.javaoperatorsdk.operator.api.reconciler.ControllerConfiguration;
 import io.javaoperatorsdk.operator.api.reconciler.Reconciler;
 
@@ -19,7 +20,7 @@ public static String getNameFor(Class<? extends Reconciler> reconcilerClass) {
     final var annotation = reconcilerClass.getAnnotation(ControllerConfiguration.class);
     if (annotation != null) {
       final var name = annotation.name();
-      if (!ControllerConfiguration.EMPTY_STRING.equals(name)) {
+      if (!Constants.EMPTY_STRING.equals(name)) {
         return name;
       }
     }

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

@@ -4,6 +4,13 @@
 
 public interface Cloner {
 
+  /**
+   * Returns a deep copy of the given object if not {@code null} or {@code null} otherwise.
+   *
+   * @param object the object to be cloned
+   * @param <R> the type of the object to be cloned
+   * @return a deep copy of the given object if it isn't {@code null}, {@code null} otherwise
+   */
   <R extends HasMetadata> R clone(R object);
 
 }

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

@@ -21,6 +21,9 @@ public interface ConfigurationService {
 
     @Override
     public HasMetadata clone(HasMetadata object) {
+      if (object == null) {
+        return null;
+      }
       try {
         return OBJECT_MAPPER.readValue(OBJECT_MAPPER.writeValueAsString(object), object.getClass());
       } catch (JsonProcessingException e) {

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

@@ -1,117 +1,45 @@
 package io.javaoperatorsdk.operator.api.config;
 
-import java.lang.reflect.ParameterizedType;
 import java.util.Collections;
-import java.util.Set;
+import java.util.List;
 
 import io.fabric8.kubernetes.api.model.HasMetadata;
-import io.fabric8.kubernetes.client.CustomResource;
 import io.javaoperatorsdk.operator.ReconcilerUtils;
 import io.javaoperatorsdk.operator.processing.event.source.controller.ResourceEventFilter;
-import io.javaoperatorsdk.operator.processing.event.source.controller.ResourceEventFilters;
+import io.javaoperatorsdk.operator.api.reconciler.Constants;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.DependentResource;
 
-public interface ControllerConfiguration<R extends HasMetadata> {
+public interface ControllerConfiguration<R extends HasMetadata> extends
+    ResourceConfiguration<R, ControllerConfiguration<R>> {
 
   default String getName() {
     return ReconcilerUtils.getDefaultReconcilerName(getAssociatedReconcilerClassName());
   }
 
-  default String getResourceTypeName() {
-    return CustomResource.getCRDName(getResourceClass());
-  }
-
   default String getFinalizer() {
     return ReconcilerUtils.getDefaultFinalizerName(getResourceTypeName());
   }
 
-  /**
-   * Retrieves the label selector that is used to filter which custom resources are actually watched
-   * by the associated controller. See
-   * https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/ for more details on
-   * syntax.
-   *
-   * @return the label selector filtering watched custom resources
-   */
-  default String getLabelSelector() {
-    return null;
-  }
-
   default boolean isGenerationAware() {
     return true;
   }
 
-  default Class<R> getResourceClass() {
-    ParameterizedType type = (ParameterizedType) getClass().getGenericInterfaces()[0];
-    return (Class<R>) type.getActualTypeArguments()[0];
-  }
-
   String getAssociatedReconcilerClassName();
 
-  default Set<String> getNamespaces() {
-    return Collections.emptySet();
-  }
-
-  default boolean watchAllNamespaces() {
-    return allNamespacesWatched(getNamespaces());
-  }
-
-  static boolean allNamespacesWatched(Set<String> namespaces) {
-    return namespaces == null || namespaces.isEmpty();
-  }
-
-  default boolean watchCurrentNamespace() {
-    return currentNamespaceWatched(getNamespaces());
-  }
-
-  static boolean currentNamespaceWatched(Set<String> namespaces) {
-    return namespaces != null
-        && namespaces.size() == 1
-        && namespaces.contains(
-            io.javaoperatorsdk.operator.api.reconciler.ControllerConfiguration.WATCH_CURRENT_NAMESPACE);
-  }
-
-  /**
-   * Computes the effective namespaces based on the set specified by the user, in particular
-   * retrieves the current namespace from the client when the user specified that they wanted to
-   * watch the current namespace only.
-   *
-   * @return a Set of namespace names the associated controller will watch
-   */
-  default Set<String> getEffectiveNamespaces() {
-    var targetNamespaces = getNamespaces();
-    if (watchCurrentNamespace()) {
-      final var parent = getConfigurationService();
-      if (parent == null) {
-        throw new IllegalStateException(
-            "Parent ConfigurationService must be set before calling this method");
-      }
-      targetNamespaces = Collections.singleton(parent.getClientConfiguration().getNamespace());
-    }
-    return targetNamespaces;
-  }
-
   default RetryConfiguration getRetryConfiguration() {
     return RetryConfiguration.DEFAULT;
   }
 
-  ConfigurationService getConfigurationService();
-
-  default void setConfigurationService(ConfigurationService service) {}
-
   default boolean useFinalizer() {
-    return !io.javaoperatorsdk.operator.api.reconciler.ControllerConfiguration.NO_FINALIZER
-        .equals(getFinalizer());
+    return !Constants.NO_FINALIZER.equals(getFinalizer());
+  }
+
+  @Override
+  default ResourceEventFilter<R, ControllerConfiguration<R>> getEventFilter() {
+    return ResourceConfiguration.super.getEventFilter();
   }
 
-  /**
-   * Allow controllers to filter events before they are provided to the
-   * {@link io.javaoperatorsdk.operator.processing.event.EventHandler}. Note that the provided
-   * filter is combined with {@link #isGenerationAware()} to compute the final set of fiolters that
-   * should be applied;
-   *
-   * @return filter
-   */
-  default ResourceEventFilter<R> getEventFilter() {
-    return ResourceEventFilters.passthrough();
+  default List<? extends DependentResource> getDependentResources() {
+    return Collections.emptyList();
   }
 }

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

@@ -14,7 +14,7 @@ public class ControllerConfigurationOverrider<R extends HasMetadata> {
   private final Set<String> namespaces;
   private RetryConfiguration retry;
   private String labelSelector;
-  private ResourceEventFilter<R> customResourcePredicate;
+  private ResourceEventFilter<R, ControllerConfiguration<R>> customResourcePredicate;
   private final ControllerConfiguration<R> original;
 
   private ControllerConfigurationOverrider(ControllerConfiguration<R> original) {
@@ -69,7 +69,7 @@ public ControllerConfigurationOverrider<R> withLabelSelector(String labelSelecto
   }
 
   public ControllerConfigurationOverrider<R> withCustomResourcePredicate(
-      ResourceEventFilter<R> customResourcePredicate) {
+      ResourceEventFilter<R, ControllerConfiguration<R>> customResourcePredicate) {
     this.customResourcePredicate = customResourcePredicate;
     return this;
   }

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

@@ -1,125 +1,77 @@
 package io.javaoperatorsdk.operator.api.config;
 
-import java.util.Collections;
 import java.util.Set;
 
 import io.fabric8.kubernetes.api.model.HasMetadata;
 import io.javaoperatorsdk.operator.processing.event.source.controller.ResourceEventFilter;
 
 public class DefaultControllerConfiguration<R extends HasMetadata>
+    extends DefaultResourceConfiguration<R, ControllerConfiguration<R>>
     implements ControllerConfiguration<R> {
 
   private final String associatedControllerClassName;
   private final String name;
-  private final String crdName;
   private final String finalizer;
-  private final boolean generationAware;
-  private final Set<String> namespaces;
-  private final boolean watchAllNamespaces;
   private final RetryConfiguration retryConfiguration;
-  private final String labelSelector;
-  private final ResourceEventFilter<R> resourceEventFilter;
-  private final Class<R> resourceClass;
-  private ConfigurationService service;
+  private final ResourceEventFilter<R, ControllerConfiguration<R>> resourceEventFilter;
+  private final boolean generationAware;
 
   public DefaultControllerConfiguration(
       String associatedControllerClassName,
       String name,
-      String crdName,
+      String resourceName,
       String finalizer,
       boolean generationAware,
       Set<String> namespaces,
       RetryConfiguration retryConfiguration,
       String labelSelector,
-      ResourceEventFilter<R> resourceEventFilter,
+      ResourceEventFilter<R, ControllerConfiguration<R>> resourceEventFilter,
       Class<R> resourceClass,
       ConfigurationService service) {
+    super(resourceName, resourceClass, namespaces, labelSelector, service);
     this.associatedControllerClassName = associatedControllerClassName;
     this.name = name;
-    this.crdName = crdName;
     this.finalizer = finalizer;
     this.generationAware = generationAware;
-    this.namespaces =
-        namespaces != null ? Collections.unmodifiableSet(namespaces) : Collections.emptySet();
-    this.watchAllNamespaces = this.namespaces.isEmpty();
     this.retryConfiguration =
         retryConfiguration == null
             ? ControllerConfiguration.super.getRetryConfiguration()
             : retryConfiguration;
-    this.labelSelector = labelSelector;
     this.resourceEventFilter = resourceEventFilter;
-    this.resourceClass =
-        resourceClass == null ? ControllerConfiguration.super.getResourceClass()
-            : resourceClass;
-    setConfigurationService(service);
   }
 
   @Override
   public String getName() {
     return name;
   }
 
-  @Override
-  public String getResourceTypeName() {
-    return crdName;
-  }
-
   @Override
   public String getFinalizer() {
     return finalizer;
   }
 
-  @Override
-  public boolean isGenerationAware() {
-    return generationAware;
-  }
-
   @Override
   public String getAssociatedReconcilerClassName() {
     return associatedControllerClassName;
   }
 
-  @Override
-  public Set<String> getNamespaces() {
-    return namespaces;
-  }
-
-  @Override
-  public boolean watchAllNamespaces() {
-    return watchAllNamespaces;
-  }
-
   @Override
   public RetryConfiguration getRetryConfiguration() {
     return retryConfiguration;
   }
 
   @Override
-  public ConfigurationService getConfigurationService() {
-    return service;
-  }
-
-  @Override
-  public void setConfigurationService(ConfigurationService service) {
-    if (this.service != null) {
-      throw new RuntimeException("A ConfigurationService is already associated with '" + name
-          + "' ControllerConfiguration. Cannot change it once set!");
-    }
-    this.service = service;
-  }
-
-  @Override
-  public String getLabelSelector() {
-    return labelSelector;
+  public boolean isGenerationAware() {
+    return generationAware;
   }
 
   @Override
-  public Class<R> getResourceClass() {
-    return resourceClass;
+  public ResourceEventFilter<R, ControllerConfiguration<R>> getEventFilter() {
+    return resourceEventFilter;
   }
 
   @Override
-  public ResourceEventFilter<R> getEventFilter() {
-    return resourceEventFilter;
+  protected String identifierForException() {
+    return "'" + name + "' ControllerConfiguration";
   }
 }