build source

vendor/k8s.io/apimachinery/pkg/api/validate/immutable.go

@@ -0,0 +1,40 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package validate
+
+import (
+	"context"
+
+	"k8s.io/apimachinery/pkg/api/operation"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+)
+
+// Immutable verifies that the specified value has not changed in the course of
+// an update operation. It does nothing if the old value is not provided.
+//
+// This function unconditionally returns a validation error as it
+// relies on the default ratcheting mechanism to only be called when a
+// change to the field has already been detected.  This avoids a redundant
+// equivalence check across ratcheting and this function.
+func Immutable[T any](_ context.Context, op operation.Operation, fldPath *field.Path, _, _ T) field.ErrorList {
+	if op.Type != operation.Update {
+		return nil
+	}
+	return field.ErrorList{
+		field.Invalid(fldPath, nil, "field is immutable").WithOrigin("immutable"),
+	}
+}