feat: add @ignore annotation to mark internal Reconciler implementations (#863)

This allows downstream tools to safely ignore the annotated Reconciler
when considering which implementations to process.

Fixes #862

Author: metacosm

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

@@ -0,0 +1,17 @@
+package io.javaoperatorsdk.operator.api.reconciler;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * An annotation for downstream tooling to ignore the annotated {@link Reconciler}. This allows to
+ * mark some implementations as not provided by user and should therefore be ignored by processes
+ * external to the SDK itself.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.TYPE})
+public @interface Ignore {
+
+}

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

@@ -27,13 +27,15 @@
 import io.javaoperatorsdk.operator.api.reconciler.DeleteControl;
 import io.javaoperatorsdk.operator.api.reconciler.EventSourceContext;
 import io.javaoperatorsdk.operator.api.reconciler.EventSourceInitializer;
+import io.javaoperatorsdk.operator.api.reconciler.Ignore;
 import io.javaoperatorsdk.operator.api.reconciler.Reconciler;
 import io.javaoperatorsdk.operator.api.reconciler.UpdateControl;
 import io.javaoperatorsdk.operator.processing.dependent.DependentResourceManager;
 import io.javaoperatorsdk.operator.processing.event.EventSourceManager;
 import io.javaoperatorsdk.operator.processing.event.source.EventSource;
 
 @SuppressWarnings({"rawtypes", "unchecked"})
+@Ignore
 public class Controller<R extends HasMetadata> implements Reconciler<R>,
     LifecycleAware, EventSourceInitializer<R> {
 

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

@@ -15,6 +15,7 @@
 import io.javaoperatorsdk.operator.api.reconciler.EventSourceContext;
 import io.javaoperatorsdk.operator.api.reconciler.EventSourceContextInjector;
 import io.javaoperatorsdk.operator.api.reconciler.EventSourceInitializer;
+import io.javaoperatorsdk.operator.api.reconciler.Ignore;
 import io.javaoperatorsdk.operator.api.reconciler.Reconciler;
 import io.javaoperatorsdk.operator.api.reconciler.UpdateControl;
 import io.javaoperatorsdk.operator.api.reconciler.dependent.DependentResourceController;
@@ -23,6 +24,7 @@
 import io.javaoperatorsdk.operator.processing.event.source.EventSource;
 
 @SuppressWarnings({"rawtypes", "unchecked"})
+@Ignore
 public class DependentResourceManager<R extends HasMetadata> implements EventSourceInitializer<R>,
     EventSourceContextInjector, Reconciler<R> {