Merge pull request #7401 from hiddeco/non-global-scheme-convert

fix(kube): use non global Scheme to convert

pkg/kube/converter.go

@@ -17,6 +17,10 @@ limitations under the License.
 package kube // import "helm.sh/helm/v3/pkg/kube"
 
 import (
+	"sync"
+
+	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
+	apiextensionsv1beta1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
 	"k8s.io/apimachinery/pkg/api/meta"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
@@ -24,6 +28,9 @@ import (
 	"k8s.io/client-go/kubernetes/scheme"
 )
 
+var k8sNativeScheme *runtime.Scheme
+var k8sNativeSchemeOnce sync.Once
+
 // AsVersioned converts the given info into a runtime.Object with the correct
 // group and version set
 func AsVersioned(info *resource.Info) runtime.Object {
@@ -33,12 +40,30 @@ func AsVersioned(info *resource.Info) runtime.Object {
 // convertWithMapper converts the given object with the optional provided
 // RESTMapping. If no mapping is provided, the default schema versioner is used
 func convertWithMapper(obj runtime.Object, mapping *meta.RESTMapping) runtime.Object {
-	var gv = runtime.GroupVersioner(schema.GroupVersions(scheme.Scheme.PrioritizedVersionsAllGroups()))
+	s := kubernetesNativeScheme()
+	var gv = runtime.GroupVersioner(schema.GroupVersions(s.PrioritizedVersionsAllGroups()))
 	if mapping != nil {
 		gv = mapping.GroupVersionKind.GroupVersion()
 	}
-	if obj, err := runtime.ObjectConvertor(scheme.Scheme).ConvertToVersion(obj, gv); err == nil {
+	if obj, err := runtime.ObjectConvertor(s).ConvertToVersion(obj, gv); err == nil {
 		return obj
 	}
 	return obj
 }
+
+// kubernetesNativeScheme returns a clean *runtime.Scheme with _only_ Kubernetes
+// native resources added to it. This is required to break free of custom resources
+// that may have been added to scheme.Scheme due to Helm being used as a package in
+// combination with e.g. a versioned kube client. If we would not do this, the client
+// may attempt to perform e.g. a 3-way-merge strategy patch for custom resources.
+func kubernetesNativeScheme() *runtime.Scheme {
+	k8sNativeSchemeOnce.Do(func() {
+		k8sNativeScheme = runtime.NewScheme()
+		scheme.AddToScheme(k8sNativeScheme)
+		// API extensions are not in the above scheme set,
+		// and must thus be added separately.
+		apiextensionsv1beta1.AddToScheme(k8sNativeScheme)
+		apiextensionsv1.AddToScheme(k8sNativeScheme)
+	})
+	return k8sNativeScheme
+}