Remove last-applied-configuration from annotations

transform/kubernetes/kubernetes.go

@@ -73,6 +73,7 @@ var fieldsToStrip = [...][]string{
 	{metadata, "creationTimestamp"},
 	{metadata, "generation"},
 	{metadata, "managedFields"},
+	{metadata, "annotations", "kubectl.kubernetes.io/last-applied-configuration"},
 	{"status"},
 }
 
@@ -569,12 +570,13 @@ func (k *KubernetesTransformPlugin) getKubernetesTransforms(obj unstructured.Uns
 	return jsonPatch, nil
 }
 
-func interfaceSlice(inStrings []string) []interface{} {
-	var outSlice []interface{}
-	for _, str := range inStrings {
-		outSlice = append(outSlice, str)
-	}
-	return outSlice
+// escapeJSONPointer escapes a string for use in a JSON Pointer path according to RFC 6901
+// ~ must be escaped as ~0
+// / must be escaped as ~1
+func escapeJSONPointer(s string) string {
+	s = strings.ReplaceAll(s, "~", "~0")
+	s = strings.ReplaceAll(s, "/", "~1")
+	return s
 }
 
 func stripFields(obj unstructured.Unstructured) (jsonpatch.Patch, error) {
@@ -585,7 +587,13 @@ func stripFields(obj unstructured.Unstructured) (jsonpatch.Patch, error) {
 			return patches, err
 		}
 		if found {
-			patch, err := jsonpatch.DecodePatch([]byte(fmt.Sprintf(opRemove, fmt.Sprintf(strings.Repeat("/%v", len(field)), interfaceSlice(field)...))))
+			// Build the JSON Pointer path with proper escaping
+			var pathParts []string
+			for _, f := range field {
+				pathParts = append(pathParts, escapeJSONPointer(f))
+			}
+			path := "/" + strings.Join(pathParts, "/")
+			patch, err := jsonpatch.DecodePatch([]byte(fmt.Sprintf(opRemove, path)))
 			if err != nil {
 				return nil, err
 			}

transform/kubernetes/kubernetes_test.go

@@ -446,6 +446,28 @@ func TestRun(t *testing.T) {
 				"multiple-testing",
 			},
 		},
+		{
+			Name: "RemoveLastAppliedConfigurationAnnotation",
+			Object: &unstructured.Unstructured{
+				Object: map[string]interface{}{
+					"kind":       "Deployment",
+					"apiVersion": "apps/v1",
+					"metadata": map[string]interface{}{
+						"name":      "test-deployment",
+						"namespace": "default",
+						"annotations": map[string]interface{}{
+							"kubectl.kubernetes.io/last-applied-configuration": `{"apiVersion":"apps/v1","kind":"Deployment","metadata":{"name":"test-deployment"}}`,
+							"other-annotation": "keep-this",
+						},
+					},
+				},
+			},
+			Response: transform.PluginResponse{
+				IsWhiteOut: false,
+				Version:    "v1",
+			},
+			PatchResponseJson: `[{"op":"remove","path":"/metadata/annotations/kubectl.kubernetes.io~1last-applied-configuration"}]`,
+		},
 		{
 			Name: "HandlePod",
 			Object: &unstructured.Unstructured{
@@ -619,7 +641,7 @@ func TestRun(t *testing.T) {
 				IsWhiteOut: false,
 				Version:    "v1",
 			},
-			PatchResponseJson: `[{"op": "remove", "path": "/spec/ports/0/nodePort"}]`,
+			PatchResponseJson: `[{"op":"remove","path":"/metadata/annotations/kubectl.kubernetes.io~1last-applied-configuration"},{"op": "remove", "path": "/spec/ports/0/nodePort"}]`,
 		},
 		{
 			Name: "HandleNodePortNamedAnnotation",
@@ -656,7 +678,7 @@ func TestRun(t *testing.T) {
 				IsWhiteOut: false,
 				Version:    "v1",
 			},
-			PatchResponseJson: `[{"op": "remove", "path": "/spec/ports/1/nodePort"}]`,
+			PatchResponseJson: `[{"op":"remove","path":"/metadata/annotations/kubectl.kubernetes.io~1last-applied-configuration"},{"op": "remove", "path": "/spec/ports/1/nodePort"}]`,
 		},
 	}