Reconcile api proposal (#1030)

Author: csviri

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

@@ -26,25 +26,27 @@ public AbstractDependentResource() {
   }
 
   @Override
-  public void reconcile(P primary, Context<P> context) {
-    final var creatable = isCreatable(primary, context);
-    final var updatable = isUpdatable(primary, context);
-    if (creatable || updatable) {
-      var maybeActual = getResource(primary);
+  public ReconcileResult<R> reconcile(P primary, Context<P> context) {
+    final var isCreatable = isCreatable(primary, context);
+    final var isUpdatable = isUpdatable(primary, context);
+    var maybeActual = getResource(primary);
+    if (isCreatable || isUpdatable) {
       if (maybeActual.isEmpty()) {
-        if (creatable) {
+        if (isCreatable) {
           var desired = desired(primary, context);
           log.debug("Creating dependent {} for primary {}", desired, primary);
-          handleCreate(desired, primary, context);
+          var createdResource = handleCreate(desired, primary, context);
+          return ReconcileResult.resourceCreated(createdResource);
         }
       } else {
         final var actual = maybeActual.get();
-        if (updatable) {
+        if (isUpdatable) {
           final var match = updater.match(actual, primary, context);
           if (!match.matched()) {
             final var desired = match.computedDesired().orElse(desired(primary, context));
             log.debug("Updating dependent {} for primary {}", desired, primary);
-            handleUpdate(actual, desired, primary, context);
+            var updatedResource = handleUpdate(actual, desired, primary, context);
+            return ReconcileResult.resourceUpdated(updatedResource);
           }
         } else {
           log.debug("Update skipped for dependent {} as it matched the existing one", actual);
@@ -55,15 +57,17 @@ public void reconcile(P primary, Context<P> context) {
           "Dependent {} is read-only, implement Creator and/or Updater interfaces to modify it",
           getClass().getSimpleName());
     }
+    return ReconcileResult.noOperation(maybeActual.orElse(null));
   }
 
-  protected void handleCreate(R desired, P primary, Context<P> context) {
+  protected R handleCreate(R desired, P primary, Context<P> context) {
     ResourceID resourceID = ResourceID.fromResource(primary);
     R created = null;
     try {
       prepareEventFiltering(desired, resourceID);
       created = creator.create(desired, primary, context);
       cacheAfterCreate(resourceID, created);
+      return created;
     } catch (RuntimeException e) {
       cleanupAfterEventFiltering(desired, resourceID, created);
       throw e;
@@ -97,13 +101,14 @@ private void prepareEventFiltering(R desired, ResourceID resourceID) {
     }
   }
 
-  protected void handleUpdate(R actual, R desired, P primary, Context<P> context) {
+  protected R handleUpdate(R actual, R desired, P primary, Context<P> context) {
     ResourceID resourceID = ResourceID.fromResource(primary);
     R updated = null;
     try {
       prepareEventFiltering(desired, resourceID);
       updated = updater.update(actual, desired, primary, context);
       cacheAfterUpdate(actual, resourceID, updated);
+      return updated;
     } catch (RuntimeException e) {
       cleanupAfterEventFiltering(desired, resourceID, updated);
       throw e;

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

@@ -6,7 +6,7 @@
 import io.javaoperatorsdk.operator.api.reconciler.Context;
 
 public interface DependentResource<R, P extends HasMetadata> {
-  void reconcile(P primary, Context<P> context);
+  ReconcileResult<R> reconcile(P primary, Context<P> context);
 
   default void cleanup(P primary, Context<P> context) {}
 

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

@@ -0,0 +1,38 @@
+package io.javaoperatorsdk.operator.api.reconciler.dependent;
+
+import java.util.Optional;
+
+public class ReconcileResult<R> {
+
+  private R resource;
+  private Operation operation;
+
+  public static <T> ReconcileResult<T> resourceCreated(T resource) {
+    return new ReconcileResult<>(resource, Operation.CREATED);
+  }
+
+  public static <T> ReconcileResult<T> resourceUpdated(T resource) {
+    return new ReconcileResult<>(resource, Operation.UPDATED);
+  }
+
+  public static <T> ReconcileResult<T> noOperation(T resource) {
+    return new ReconcileResult<>(resource, Operation.NONE);
+  }
+
+  private ReconcileResult(R resource, Operation operation) {
+    this.resource = resource;
+    this.operation = operation;
+  }
+
+  public Optional<R> getResource() {
+    return Optional.ofNullable(resource);
+  }
+
+  public Operation getOperation() {
+    return operation;
+  }
+
+  public enum Operation {
+    CREATED, UPDATED, NONE
+  }
+}

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/external/AbstractSimpleDependentResource.java

@@ -7,6 +7,7 @@
 import io.javaoperatorsdk.operator.api.reconciler.dependent.AbstractDependentResource;
 import io.javaoperatorsdk.operator.api.reconciler.dependent.DesiredEqualsMatcher;
 import io.javaoperatorsdk.operator.api.reconciler.dependent.Matcher;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.ReconcileResult;
 import io.javaoperatorsdk.operator.processing.event.ResourceID;
 import io.javaoperatorsdk.operator.processing.event.source.ConcurrentHashMapCache;
 import io.javaoperatorsdk.operator.processing.event.source.UpdatableCache;
@@ -43,11 +44,11 @@ public Optional<R> getResource(HasMetadata primaryResource) {
   public abstract Optional<R> fetchResource(HasMetadata primaryResource);
 
   @Override
-  public void reconcile(P primary, Context<P> context) {
+  public ReconcileResult<R> reconcile(P primary, Context<P> context) {
     var resourceId = ResourceID.fromResource(primary);
     Optional<R> resource = fetchResource(primary);
     resource.ifPresentOrElse(r -> cache.put(resourceId, r), () -> cache.remove(resourceId));
-    super.reconcile(primary, context);
+    return super.reconcile(primary, context);
   }
 
   public void cleanup(P primary, Context<P> context) {
@@ -56,15 +57,17 @@ public void cleanup(P primary, Context<P> context) {
   }
 
   @Override
-  protected void handleCreate(R desired, P primary, Context<P> context) {
+  protected R handleCreate(R desired, P primary, Context<P> context) {
     var res = this.creator.create(desired, primary, context);
     cache.put(ResourceID.fromResource(primary), res);
+    return res;
   }
 
   @Override
-  protected void handleUpdate(R actual, R desired, P primary, Context<P> context) {
+  protected R handleUpdate(R actual, R desired, P primary, Context<P> context) {
     var res = updater.update(actual, desired, primary, context);
     cache.put(ResourceID.fromResource(primary), res);
+    return res;
   }
 
   public Matcher.Result<R> match(R actualResource, P primary, Context context) {