Observed generation in status support

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

@@ -0,0 +1,28 @@
+package io.javaoperatorsdk.operator.api;
+
+import java.util.Optional;
+
+import io.fabric8.kubernetes.client.CustomResource;
+
+/**
+ * If the custom resource's status implements this interface, the observed generation will be
+ * automatically handled. The last observed generation will be updated on status when the status is
+ * instructed to be updated (see below). In addition to that, controller configuration will be
+ * checked if is set to generation aware. If generation aware config is turned off, this interface
+ * is ignored.
+ *
+ * In order to work the status object returned by CustomResource.getStatus() should not be null. In
+ * addition to that from the controller that the
+ * {@link UpdateControl#updateStatusSubResource(CustomResource)} or
+ * {@link UpdateControl#updateCustomResourceAndStatus(CustomResource)} should be returned. The
+ * observed generation is not updated in other cases.
+ *
+ * @see ObservedGenerationAwareStatus
+ */
+public interface ObservedGenerationAware {
+
+  void setObservedGeneration(Long generation);
+
+  Optional<Long> getObservedGeneration();
+
+}

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

@@ -0,0 +1,21 @@
+package io.javaoperatorsdk.operator.api;
+
+import java.util.Optional;
+
+/**
+ * A helper base class for status sub-resources classes to extend to support generate awareness.
+ */
+public class ObservedGenerationAwareStatus implements ObservedGenerationAware {
+
+  private Long observedGeneration;
+
+  @Override
+  public void setObservedGeneration(Long generation) {
+    this.observedGeneration = generation;
+  }
+
+  @Override
+  public Optional<Long> getObservedGeneration() {
+    return Optional.ofNullable(observedGeneration);
+  }
+}

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

@@ -117,18 +117,32 @@ private PostExecutionControl<R> handleCreateOrUpdate(
             .getCustomResource()
             .getMetadata()
             .setResourceVersion(updatedCustomResource.getMetadata().getResourceVersion());
-        updatedCustomResource =
-            customResourceFacade.updateStatus(updateControl.getCustomResource());
+        updatedCustomResource = updateStatusGenerationAware(updateControl.getCustomResource());
       } else if (updateControl.isUpdateStatusSubResource()) {
-        updatedCustomResource =
-            customResourceFacade.updateStatus(updateControl.getCustomResource());
+        updatedCustomResource = updateStatusGenerationAware(updateControl.getCustomResource());
       } else if (updateControl.isUpdateCustomResource()) {
         updatedCustomResource = updateCustomResource(updateControl.getCustomResource());
       }
       return createPostExecutionControl(updatedCustomResource, updateControl);
     }
   }
 
+  private R updateStatusGenerationAware(R customResource) {
+    updateStatusObservedGenerationIfRequired(customResource);
+    return customResourceFacade.updateStatus(customResource);
+  }
+
+  private void updateStatusObservedGenerationIfRequired(R customResource) {
+    if (controller.getConfiguration().isGenerationAware()) {
+      var status = customResource.getStatus();
+      // Note that if status is null we won't update the observed generation.
+      if (status instanceof ObservedGenerationAware) {
+        ((ObservedGenerationAware) status)
+            .setObservedGeneration(customResource.getMetadata().getGeneration());
+      }
+    }
+  }
+
   private PostExecutionControl<R> createPostExecutionControl(R updatedCustomResource,
       UpdateControl<R> updateControl) {
     PostExecutionControl<R> postExecutionControl;

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

@@ -1,6 +1,7 @@
 package io.javaoperatorsdk.operator.processing.event.internal;
 
 import io.fabric8.kubernetes.client.CustomResource;
+import io.javaoperatorsdk.operator.api.ObservedGenerationAware;
 
 /**
  * Convenience implementations of, and utility methods for, {@link CustomResourceEventFilter}.
@@ -21,9 +22,18 @@ public final class CustomResourceEventFilters {
       };
 
   private static final CustomResourceEventFilter<CustomResource> GENERATION_AWARE =
-      (configuration, oldResource, newResource) -> oldResource == null
-          || !configuration.isGenerationAware()
-          || oldResource.getMetadata().getGeneration() < newResource.getMetadata().getGeneration();
+      (configuration, oldResource, newResource) -> {
+        final var status = newResource.getStatus();
+        final var generationAware = configuration.isGenerationAware();
+        if (generationAware && status instanceof ObservedGenerationAware) {
+          var actualGeneration = newResource.getMetadata().getGeneration();
+          var observedGeneration = ((ObservedGenerationAware) status)
+              .getObservedGeneration();
+          return observedGeneration.map(aLong -> actualGeneration > aLong).orElse(true);
+        }
+        return oldResource == null || !generationAware ||
+            oldResource.getMetadata().getGeneration() < newResource.getMetadata().getGeneration();
+      };
 
   private static final CustomResourceEventFilter<CustomResource> PASSTHROUGH =
       (configuration, oldResource, newResource) -> true;

operator-framework-core/src/test/java/io/javaoperatorsdk/operator/processing/EventDispatcherTest.java

@@ -9,6 +9,7 @@
 import org.mockito.ArgumentCaptor;
 import org.mockito.ArgumentMatchers;
 
+import io.fabric8.kubernetes.api.model.ObjectMeta;
 import io.fabric8.kubernetes.client.CustomResource;
 import io.javaoperatorsdk.operator.TestUtils;
 import io.javaoperatorsdk.operator.api.Context;
@@ -23,6 +24,7 @@
 import io.javaoperatorsdk.operator.processing.event.Event;
 import io.javaoperatorsdk.operator.processing.event.internal.CustomResourceEvent;
 import io.javaoperatorsdk.operator.processing.event.internal.ResourceAction;
+import io.javaoperatorsdk.operator.sample.observedgeneration.ObservedGenCustomResource;
 
 import static io.javaoperatorsdk.operator.processing.event.internal.ResourceAction.ADDED;
 import static io.javaoperatorsdk.operator.processing.event.internal.ResourceAction.UPDATED;
@@ -320,6 +322,33 @@ void reScheduleOnDeleteWithoutFinalizerRemoval() {
     assertThat(control.getReScheduleDelay().get()).isEqualTo(1000L);
   }
 
+  @Test
+  void setObservedGenerationForStatusIfNeeded() {
+    var observedGenResource = createObservedGenCustomResource();
+
+    when(configuration.isGenerationAware()).thenReturn(true);
+    when(controller.createOrUpdateResource(eq(observedGenResource), any()))
+        .thenReturn(
+            UpdateControl.updateStatusSubResource(observedGenResource));
+
+    when(customResourceFacade.updateStatus(observedGenResource)).thenReturn(observedGenResource);
+
+    PostExecutionControl<ObservedGenCustomResource> control = eventDispatcher.handleExecution(
+        executionScopeWithCREvent(ADDED, observedGenResource));
+    assertThat(control.getUpdatedCustomResource().get().getStatus().getObservedGeneration().get())
+        .isEqualTo(1L);
+  }
+
+  @Test
+  private ObservedGenCustomResource createObservedGenCustomResource() {
+    ObservedGenCustomResource observedGenCustomResource = new ObservedGenCustomResource();
+    observedGenCustomResource.setMetadata(new ObjectMeta());
+    observedGenCustomResource.getMetadata().setGeneration(1L);
+    observedGenCustomResource.getMetadata().setFinalizers(new ArrayList<>());
+    observedGenCustomResource.getMetadata().getFinalizers().add(DEFAULT_FINALIZER);
+    return observedGenCustomResource;
+  }
+
   private void markForDeletion(CustomResource customResource) {
     customResource.getMetadata().setDeletionTimestamp("2019-8-10");
   }

operator-framework-core/src/test/java/io/javaoperatorsdk/operator/processing/event/internal/CustomResourceEventFilterTest.java

@@ -7,6 +7,8 @@
 import org.junit.jupiter.api.Test;
 
 import io.fabric8.kubernetes.api.model.KubernetesResourceList;
+import io.fabric8.kubernetes.api.model.ObjectMeta;
+import io.fabric8.kubernetes.client.CustomResource;
 import io.fabric8.kubernetes.client.dsl.MixedOperation;
 import io.fabric8.kubernetes.client.dsl.Resource;
 import io.javaoperatorsdk.operator.TestUtils;
@@ -15,6 +17,7 @@
 import io.javaoperatorsdk.operator.api.config.DefaultControllerConfiguration;
 import io.javaoperatorsdk.operator.processing.ConfiguredController;
 import io.javaoperatorsdk.operator.processing.event.EventHandler;
+import io.javaoperatorsdk.operator.sample.observedgeneration.ObservedGenCustomResource;
 import io.javaoperatorsdk.operator.sample.simple.TestCustomResource;
 
 import static org.mockito.Mockito.any;
@@ -94,6 +97,31 @@ public void eventFilteredByCustomPredicateAndGenerationAware() {
     verify(eventHandler, times(1)).handleEvent(any());
   }
 
+  @Test
+  public void observedGenerationFiltering() {
+    var config = new ObservedGenControllerConfig(FINALIZER, true, null);
+    when(config.getConfigurationService().getResourceCloner())
+        .thenReturn(ConfigurationService.DEFAULT_CLONER);
+
+    var controller = new ObservedGenConfiguredController(config);
+    var eventSource = new CustomResourceEventSource<>(controller);
+    eventSource.setEventHandler(eventHandler);
+
+    ObservedGenCustomResource cr = new ObservedGenCustomResource();
+    cr.setMetadata(new ObjectMeta());
+    cr.getMetadata().setFinalizers(List.of(FINALIZER));
+    cr.getMetadata().setGeneration(5L);
+    cr.getStatus().setObservedGeneration(5L);
+
+    eventSource.eventReceived(ResourceAction.UPDATED, cr, null);
+    verify(eventHandler, times(0)).handleEvent(any());
+
+    cr.getMetadata().setGeneration(6L);
+
+    eventSource.eventReceived(ResourceAction.UPDATED, cr, null);
+    verify(eventHandler, times(1)).handleEvent(any());
+  }
+
   @Test
   public void eventNotFilteredByCustomPredicateIfFinalizerIsRequired() {
     var config = new TestControllerConfig(
@@ -124,11 +152,25 @@ public void eventNotFilteredByCustomPredicateIfFinalizerIsRequired() {
     verify(eventHandler, times(2)).handleEvent(any());
   }
 
-  private static class TestControllerConfig extends
-      DefaultControllerConfiguration<TestCustomResource> {
-
+  private static class TestControllerConfig extends ControllerConfig<TestCustomResource> {
     public TestControllerConfig(String finalizer, boolean generationAware,
         CustomResourceEventFilter<TestCustomResource> eventFilter) {
+      super(finalizer, generationAware, eventFilter, TestCustomResource.class);
+    }
+  }
+  private static class ObservedGenControllerConfig
+      extends ControllerConfig<ObservedGenCustomResource> {
+    public ObservedGenControllerConfig(String finalizer, boolean generationAware,
+        CustomResourceEventFilter<ObservedGenCustomResource> eventFilter) {
+      super(finalizer, generationAware, eventFilter, ObservedGenCustomResource.class);
+    }
+  }
+
+  private static class ControllerConfig<T extends CustomResource<?, ?>> extends
+      DefaultControllerConfiguration<T> {
+
+    public ControllerConfig(String finalizer, boolean generationAware,
+        CustomResourceEventFilter<T> eventFilter, Class<T> customResourceClass) {
       super(
           null,
           null,
@@ -139,7 +181,7 @@ public TestControllerConfig(String finalizer, boolean generationAware,
           null,
           null,
           eventFilter,
-          TestCustomResource.class,
+          customResourceClass,
           mock(ConfigurationService.class));
 
       when(getConfigurationService().getResourceCloner())
@@ -158,4 +200,18 @@ public MixedOperation<TestCustomResource, KubernetesResourceList<TestCustomResou
       return mock(MixedOperation.class);
     }
   }
+
+  private static class ObservedGenConfiguredController
+      extends ConfiguredController<ObservedGenCustomResource> {
+
+    public ObservedGenConfiguredController(
+        ControllerConfiguration<ObservedGenCustomResource> configuration) {
+      super(null, configuration, null);
+    }
+
+    @Override
+    public MixedOperation<ObservedGenCustomResource, KubernetesResourceList<ObservedGenCustomResource>, Resource<ObservedGenCustomResource>> getCRClient() {
+      return mock(MixedOperation.class);
+    }
+  }
 }

operator-framework-core/src/test/java/io/javaoperatorsdk/operator/sample/observedgeneration/ObservedGenCustomResource.java

@@ -0,0 +1,21 @@
+package io.javaoperatorsdk.operator.sample.observedgeneration;
+
+import io.fabric8.kubernetes.client.CustomResource;
+import io.fabric8.kubernetes.model.annotation.Group;
+import io.fabric8.kubernetes.model.annotation.Version;
+
+@Group("sample.javaoperatorsdk.io")
+@Version("v1")
+public class ObservedGenCustomResource
+    extends CustomResource<ObservedGenSpec, ObservedGenStatus> {
+
+  @Override
+  protected ObservedGenSpec initSpec() {
+    return new ObservedGenSpec();
+  }
+
+  @Override
+  protected ObservedGenStatus initStatus() {
+    return new ObservedGenStatus();
+  }
+}

operator-framework-core/src/test/java/io/javaoperatorsdk/operator/sample/observedgeneration/ObservedGenSpec.java

@@ -0,0 +1,21 @@
+package io.javaoperatorsdk.operator.sample.observedgeneration;
+
+public class ObservedGenSpec {
+
+  private String value;
+
+  public String getValue() {
+    return value;
+  }
+
+  public void setValue(String value) {
+    this.value = value;
+  }
+
+  @Override
+  public String toString() {
+    return "TestCustomResourceSpec{" +
+        "value='" + value + '\'' +
+        '}';
+  }
+}

operator-framework-core/src/test/java/io/javaoperatorsdk/operator/sample/observedgeneration/ObservedGenStatus.java

@@ -0,0 +1,7 @@
+package io.javaoperatorsdk.operator.sample.observedgeneration;
+
+import io.javaoperatorsdk.operator.api.ObservedGenerationAwareStatus;
+
+public class ObservedGenStatus extends ObservedGenerationAwareStatus {
+
+}