Avoid reusing list objects across serve-readiness probes

Signed-off-by: Andreas Fritzler <andreas.fritzler@sap.com>

Author: afritzler

utils/envtest/envtest.go

@@ -690,15 +690,15 @@ const serveReadinessStableDuration = 500 * time.Millisecond
 // aggregated server, so it observes the transient 503 startup window and absorbs
 // it before the test suite proceeds.
 func waitUntilGroupVersionsServe(ctx context.Context, c client.Client, scheme *runtime.Scheme, gvs ...schema.GroupVersion) error {
-	var lists []client.ObjectList
+	var listTypes []reflect.Type
 	for _, gv := range gvs {
-		list, ok := newListForGroupVersion(scheme, gv)
+		listType, ok := firstListTypeForGroupVersion(scheme, gv)
 		if !ok {
 			continue
 		}
-		lists = append(lists, list)
+		listTypes = append(listTypes, listType)
 	}
-	if len(lists) == 0 {
+	if len(listTypes) == 0 {
 		return nil
 	}
 
@@ -710,7 +710,8 @@ func waitUntilGroupVersionsServe(ctx context.Context, c client.Client, scheme *r
 	successes := 0
 	var lastErr error
 	if err := wait.PollUntilContextCancel(ctx, serveReadinessPollInterval, true, func(ctx context.Context) (bool, error) {
-		for _, list := range lists {
+		for _, listType := range listTypes {
+			list := reflect.New(listType).Interface().(client.ObjectList)
 			if err := c.List(ctx, list); err != nil {
 				if !isTransientServeError(err) {
 					return false, fmt.Errorf("unexpected error probing aggregated api server: %w", err)
@@ -731,10 +732,12 @@ func waitUntilGroupVersionsServe(ctx context.Context, c client.Client, scheme *r
 	return nil
 }
 
-// newListForGroupVersion returns a fresh list object for the first list kind
-// registered for the given group version (e.g. *VolumeList), constructed via the
-// scheme so the scheme stays the single source of truth for type instantiation.
-func newListForGroupVersion(scheme *runtime.Scheme, gv schema.GroupVersion) (client.ObjectList, bool) {
+// firstListTypeForGroupVersion returns the reflect.Type of the first list kind
+// registered for the given group version (e.g. *VolumeList). Kind resolution is
+// deterministic (sorted) and the scheme is the single source of truth for type
+// discovery, so callers can safely hold the resulting type and instantiate fresh
+// list objects from it.
+func firstListTypeForGroupVersion(scheme *runtime.Scheme, gv schema.GroupVersion) (reflect.Type, bool) {
 	kinds := make([]string, 0, len(scheme.KnownTypes(gv)))
 	for kind := range scheme.KnownTypes(gv) {
 		kinds = append(kinds, kind)
@@ -746,7 +749,7 @@ func newListForGroupVersion(scheme *runtime.Scheme, gv schema.GroupVersion) (cli
 			continue
 		}
 		if list, ok := obj.(client.ObjectList); ok {
-			return list, true
+			return reflect.TypeOf(list), true
 		}
 	}
 	return nil, false