From a6dc42201c45570fcf585dd0df6c219888cab2c4 Mon Sep 17 00:00:00 2001
From: irbekrm <irbekrm@gmail.com>
Date: Thu, 20 Apr 2023 10:15:44 +0100
Subject: [PATCH] Ensures that partial meta secrets are cleaned up before
 caching

Signed-off-by: irbekrm <irbekrm@gmail.com>
---
 internal/informers/core_filteredsecrets.go |  6 ++--
 internal/informers/transfomers.go          | 40 ++++++++++++++++++++++
 2 files changed, 44 insertions(+), 2 deletions(-)
 create mode 100644 internal/informers/transfomers.go

diff --git a/internal/informers/core_filteredsecrets.go b/internal/informers/core_filteredsecrets.go
index 2a05eb5d0..3fbd07855 100644
--- a/internal/informers/core_filteredsecrets.go
+++ b/internal/informers/core_filteredsecrets.go
@@ -164,9 +164,11 @@ type filteredSecretInformer struct {
 
 func (f *filteredSecretInformer) Informer() Informer {
 	typedInformer := f.typedInformerFactory.InformerFor(&corev1.Secret{}, f.newTyped)
-	// TODO: set any possible transforms
+
 	metadataInformer := f.metadataInformerFactory.ForResource(secretsGVR).Informer()
-	// TODO: set transform on metadataInformer to remove last applied annotation etc
+	if err := metadataInformer.SetTransform(partialMetadataRemoveAll); err != nil {
+		panic(fmt.Sprintf("internal error: error setting transfomer on the metadata informer: %v", err))
+	}
 	return &informer{
 		typedInformer:    typedInformer,
 		metadataInformer: metadataInformer,
diff --git a/internal/informers/transfomers.go b/internal/informers/transfomers.go
new file mode 100644
index 000000000..779f5c319
--- /dev/null
+++ b/internal/informers/transfomers.go
@@ -0,0 +1,40 @@
+/*
+Copyright 2023 The cert-manager 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 informers
+
+import (
+	"fmt"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/tools/cache"
+)
+
+var _ cache.TransformFunc = partialMetadataRemoveAll
+
+// partialMetadataRemoveAll implements a cache.TransformFunc that removes
+// labels, annotations and managed
+// fields from PartialObjectMetadata.
+func partialMetadataRemoveAll(obj interface{}) (interface{}, error) {
+	partialMeta, ok := obj.(*metav1.PartialObjectMetadata)
+	if !ok {
+		return nil, fmt.Errorf("internal error: cannot cast object %#+v to PartialObjectMetadata", obj)
+	}
+	partialMeta.Annotations = nil
+	partialMeta.ManagedFields = nil
+	partialMeta.Labels = nil
+	return partialMeta, nil
+}