fix: Update K8s Spec for read-only resources when AWS state diverges

apis/core/v1alpha1/annotations.go

@@ -75,11 +75,12 @@ const (
 	// resource manager will leave the AWS resource intact when the K8s resource
 	// is deleted.
 	AnnotationDeletionPolicy = AnnotationPrefix + "deletion-policy"
-	// AnnotationReadOnly is an annotation whose value is a boolean indicating
-	// whether the resource is read-only. If this annotation is set to true on a
-	// CR, that means the user is indicating to the ACK service controller that
-	// the resource is read-only and should not be created/patched/deleted by the
-	// ACK service controller.
+	// AnnotationReadOnly is an annotation indicating whether the resource is
+	// read-only. If this annotation is set to "true" on a CR, the resource
+	// is read-only and will not be created/patched/deleted in AWS, and its
+	// K8s Spec will not be synced. If the value is "always", it acts as
+	// read-only but the controller WILL patch the K8s Spec and Metadata to
+	// reflect the latest observed state from AWS.
 	AnnotationReadOnly = AnnotationPrefix + "read-only"
 	// AnnotationAdoptionPolicy is an annotation whose value is the identifier for whether
 	// we will attempt adoption only (value = adopt-only) or attempt a create if resource 

pkg/runtime/reconciler.go

@@ -609,11 +609,23 @@ func (r *resourceReconciler) Sync(
 	} else if isReadOnly {
 		delta := r.rd.Delta(desired, latest)
 		if delta.DifferentAt("Spec") {
-			rlog.Info(
-				"desired resource state has changed, but resource is read-only - skipping update",
-				"skipped", true,
-				"diff", delta.Differences,
-			)
+			if IsReadOnlyAlwaysSync(desired) {
+				rlog.Info(
+					"desired resource state has changed, resource is read-only: always - syncing Spec",
+					"skipped", false,
+					"diff", delta.Differences,
+				)
+				latest, err = r.patchResourceMetadataAndSpec(ctx, rm, desired, latest)
+				if err != nil {
+					return latest, err
+				}
+			} else {
+				rlog.Info(
+					"desired resource state has changed, but resource is read-only - skipping update",
+					"skipped", true,
+					"diff", delta.Differences,
+				)
+			}
 		}
 		return latest, nil
 	} else {

pkg/runtime/util.go

@@ -98,7 +98,24 @@ func IsReadOnly(res acktypes.AWSResource) bool {
 	}
 	for k, v := range mo.GetAnnotations() {
 		if k == ackv1alpha1.AnnotationReadOnly {
-			return strings.ToLower(v) == "true"
+			val := strings.ToLower(v)
+			return val == "true" || val == "always"
+		}
+	}
+	return false
+}
+
+// IsReadOnlyAlwaysSync returns true if the supplied AWSResource has the
+// read-only annotation set to "always".
+func IsReadOnlyAlwaysSync(res acktypes.AWSResource) bool {
+	mo := res.MetaObject()
+	if mo == nil {
+		// Should never happen... if it does, it's buggy code.
+		panic("IsReadOnlyAlwaysSync received resource with nil RuntimeObject")
+	}
+	for k, v := range mo.GetAnnotations() {
+		if k == ackv1alpha1.AnnotationReadOnly {
+			return strings.ToLower(v) == "always"
 		}
 	}
 	return false