docs: add javadoc

Signed-off-by: Chris Laprun <claprun@redhat.com>

Author: metacosm

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

@@ -116,6 +116,7 @@ public <R extends HasMetadata> ControllerConfiguration<R> getConfigurationFor(
     if (configuration == null) {
       logMissingReconcilerWarning(key, getReconcilersNameMessage());
     } else {
+      // if a reconciler is also a ConfigurableReconciler, update and replace its configuration
       if (reconciler instanceof ConfigurableReconciler<?> configurableReconciler) {
         final var overrider = ControllerConfigurationOverrider.override(configuration);
         configurableReconciler.updateConfigurationFrom(overrider);

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

@@ -1,7 +1,25 @@
 package io.javaoperatorsdk.operator.api.config;
 
 import io.fabric8.kubernetes.api.model.HasMetadata;
+import io.javaoperatorsdk.operator.api.reconciler.Reconciler;
 
+/**
+ * Implement to change a {@link io.javaoperatorsdk.operator.api.reconciler.Reconciler}'s
+ * configuration at runtime
+ *
+ * @param <P> the primary resource type of the reconciler
+ * @since 5.1
+ */
 public interface ConfigurableReconciler<P extends HasMetadata> {
+  /**
+   * Updates the reconciler's configuration by applying the modifications specified by the provided
+   * {@link ControllerConfigurationOverrider} and then replacing the existing configuration in the
+   * {@link ConfigurationService} for this reconciler. Note that this method will not be applied if
+   * there is no configuration (as determined by {@link
+   * ConfigurationService#getConfigurationFor(Reconciler)} for the reconciler.
+   *
+   * @param configOverrider provides the modifications to apply to the existing reconciler's
+   *     configuration
+   */
   void updateConfigurationFrom(ControllerConfigurationOverrider<P> configOverrider);
 }