feat: improve customizability of SSABasedGenericKubernetesResourceMatcher (#2757)

Signed-off-by: Mattis Bratland <mattis.bratland@novari.no>

Author: murillio4

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

@@ -110,7 +110,7 @@ public boolean matches(R actual, R desired, Context<?> context) {
 
     removeIrrelevantValues(desiredMap);
 
-    var matches = prunedActual.equals(desiredMap);
+    var matches = matches(prunedActual, desiredMap, actual, desired, context);
     if (!matches && log.isDebugEnabled() && LoggingUtils.isNotSensitiveResource(desired)) {
       var diff = getDiff(prunedActual, desiredMap, objectMapper);
       log.debug(
@@ -125,6 +125,28 @@ public boolean matches(R actual, R desired, Context<?> context) {
     return matches;
   }
 
+  /**
+   * Compares the desired and actual resources for equality.
+   *
+   * <p>This method can be overridden to implement custom matching logic. The {@code actualMap} is a
+   * cleaned-up version of the actual resource with managed fields and irrelevant values removed.
+   *
+   * @param actualMap the actual resource represented as a map
+   * @param desiredMap the desired resource represented as a map
+   * @param actual the actual resource object
+   * @param desired the desired resource object
+   * @param context the current matching context
+   * @return {@code true} if the resources are equal, otherwise {@code false}
+   */
+  protected boolean matches(
+      Map<String, Object> actualMap,
+      Map<String, Object> desiredMap,
+      R actual,
+      R desired,
+      Context<?> context) {
+    return actualMap.equals(desiredMap);
+  }
+
   private String getDiff(
       Map<String, Object> prunedActualMap,
       Map<String, Object> desiredMap,

operator-framework-core/src/test/java/io/javaoperatorsdk/operator/processing/dependent/kubernetes/SSABasedGenericKubernetesResourceMatcherTest.java

@@ -236,6 +236,37 @@ void testSanitizeState_daemonSetWithResources_withMismatch() {
     assertThat(matcher.matches(actualDaemonSet, desiredDaemonSet, mockedContext)).isFalse();
   }
 
+  @ParameterizedTest
+  @ValueSource(booleans = {true, false})
+  void testCustomMatcher_returnsExpectedMatchBasedOnReadOnlyLabel(boolean readOnly) {
+    var desiredConfigMap =
+        loadResource("configmap.empty-owner-reference-desired.yaml", ConfigMap.class);
+    desiredConfigMap.getData().put("key1", "another value");
+    var actualConfigMap = loadResource("configmap.empty-owner-reference.yaml", ConfigMap.class);
+    actualConfigMap.getMetadata().getLabels().put("readonly", Boolean.toString(readOnly));
+
+    var matcher = new ReadOnlyAwareMatcher<ConfigMap>();
+    assertThat(matcher.matches(actualConfigMap, desiredConfigMap, mockedContext))
+        .isEqualTo(readOnly);
+  }
+
+  private static class ReadOnlyAwareMatcher<T extends HasMetadata>
+      extends SSABasedGenericKubernetesResourceMatcher<T> {
+    @Override
+    protected boolean matches(
+        Map<String, Object> actualMap,
+        Map<String, Object> desiredMap,
+        T actual,
+        T desired,
+        Context<?> context) {
+      var readonly = actual.getMetadata().getLabels().get("readonly");
+      if (readonly != null && readonly.equals("true")) {
+        return true;
+      }
+      return actualMap.equals(desiredMap);
+    }
+  }
+
   private static <R> R loadResource(String fileName, Class<R> clazz) {
     return ReconcilerUtils.loadYaml(
         clazz, SSABasedGenericKubernetesResourceMatcherTest.class, fileName);