- Updated cache.Options with a DefaultTransform function that rem…

…oves managed fields and the `"kubectl.kubernetes.io/last-applied-configuration"` annotation from objects before storing them in the cache. (#2300)

- Stripping managed fields reduces cache memory overhead, which improves performance in large clusters.
- Removing the `"last-applied-configuration"` annotation prevents unnecessary cache bloat and reduces redundant reconciliation triggers caused by changes to this field, which does not require for operation.

This enhancement minimizes cache size and resource usage, improving controller runtime performance and memory management.

Co-authored-by: afdesk <[email protected]>

pkg/operator/operator.go

@@ -30,6 +30,7 @@ import (
 	mp "github.com/aquasecurity/trivy/pkg/policy"
 	"github.com/bluele/gcache"
 	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/cli-runtime/pkg/genericclioptions"
 	"k8s.io/client-go/kubernetes"
 	ctrl "sigs.k8s.io/controller-runtime"
@@ -73,6 +74,23 @@ func Start(ctx context.Context, buildInfo trivyoperator.BuildInfo, operatorConfi
 				},
 			},
 		},
+		Cache: cache.Options{
+			DefaultTransform: func(obj interface{}) (interface{}, error) {
+				obj, err := cache.TransformStripManagedFields()(obj)
+				if err != nil {
+					return obj, err
+				}
+				if metaObj, ok := obj.(metav1.ObjectMetaAccessor); ok {
+					annotations := metaObj.GetObjectMeta().GetAnnotations()
+					if annotations != nil {
+						delete(annotations, "kubectl.kubernetes.io/last-applied-configuration")
+						metaObj.GetObjectMeta().SetAnnotations(annotations)
+					}
+				}
+
+				return obj, nil
+			},
+		},
 		Controller: controllerconfig.Controller{SkipNameValidation: &skipNameValidation},
 	}