fix: restore backwards compatibility

Note that the current implementation is flawed because custom
ResourceUpdatePreProcessor should be registered to be found when
attempting to use custom matching logic. See also #1914 for more
details.

Author: metacosm

Diff for: operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/kubernetes/ResourceUpdatePreProcessor.java

@@ -1,11 +1,36 @@
 package io.javaoperatorsdk.operator.processing.dependent.kubernetes;
 
 import io.fabric8.kubernetes.api.model.HasMetadata;
+import io.fabric8.zjsonpatch.JsonDiff;
+import io.javaoperatorsdk.operator.ReconcilerUtils;
+import io.javaoperatorsdk.operator.api.config.ConfigurationServiceProvider;
 import io.javaoperatorsdk.operator.api.reconciler.Context;
 
 public interface ResourceUpdatePreProcessor<R extends HasMetadata> {
 
   R replaceSpecOnActual(R actual, R desired, Context<?> context);
 
-  boolean matches(R actual, R desired, boolean equality);
+  default boolean matches(R actual, R desired, boolean equality) {
+    final var objectMapper = ConfigurationServiceProvider.instance().getObjectMapper();
+
+    // reflection will be replaced by this:
+    // https://github.com/fabric8io/kubernetes-client/issues/3816
+    var desiredSpecNode = objectMapper.valueToTree(ReconcilerUtils.getSpec(desired));
+    var actualSpecNode = objectMapper.valueToTree(ReconcilerUtils.getSpec(actual));
+    var diffJsonPatch = JsonDiff.asJson(desiredSpecNode, actualSpecNode);
+    // In case of equality is set to true, no diffs are allowed, so we return early if diffs exist
+    // On contrary (if equality is false), "add" is allowed for cases when for some
+    // resources Kubernetes fills-in values into spec.
+    final var diffNumber = diffJsonPatch.size();
+    if (equality && diffNumber > 0) {
+      return false;
+    }
+    for (int i = 0; i < diffNumber; i++) {
+      String operation = diffJsonPatch.get(i).get("op").asText();
+      if (!operation.equals("add")) {
+        return false;
+      }
+    }
+    return true;
+  }
 }

Diff for: operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/kubernetes/processors/GenericResourceUpdatePreProcessor.java

@@ -10,7 +10,6 @@
 import io.fabric8.kubernetes.api.model.rbac.ClusterRoleBinding;
 import io.fabric8.kubernetes.api.model.rbac.Role;
 import io.fabric8.kubernetes.api.model.rbac.RoleBinding;
-import io.fabric8.zjsonpatch.JsonDiff;
 import io.javaoperatorsdk.operator.ReconcilerUtils;
 import io.javaoperatorsdk.operator.api.config.ConfigurationServiceProvider;
 import io.javaoperatorsdk.operator.api.reconciler.Context;
@@ -50,29 +49,4 @@ protected void updateClonedActual(R actual, R desired) {
     var desiredSpec = ReconcilerUtils.getSpec(desired);
     ReconcilerUtils.setSpec(actual, desiredSpec);
   }
-
-  @Override
-  public boolean matches(R actual, R desired, boolean equality) {
-    final var objectMapper = ConfigurationServiceProvider.instance().getObjectMapper();
-
-    // reflection will be replaced by this:
-    // https://github.com/fabric8io/kubernetes-client/issues/3816
-    var desiredSpecNode = objectMapper.valueToTree(ReconcilerUtils.getSpec(desired));
-    var actualSpecNode = objectMapper.valueToTree(ReconcilerUtils.getSpec(actual));
-    var diffJsonPatch = JsonDiff.asJson(desiredSpecNode, actualSpecNode);
-    // In case of equality is set to true, no diffs are allowed, so we return early if diffs exist
-    // On contrary (if equality is false), "add" is allowed for cases when for some
-    // resources Kubernetes fills-in values into spec.
-    final var diffNumber = diffJsonPatch.size();
-    if (equality && diffNumber > 0) {
-      return false;
-    }
-    for (int i = 0; i < diffNumber; i++) {
-      String operation = diffJsonPatch.get(i).get("op").asText();
-      if (!operation.equals("add")) {
-        return false;
-      }
-    }
-    return true;
-  }
 }