Simplify kubelet file config field allowlists

pkg/kubelet/apis/config/helpers_test.go

@@ -35,7 +35,7 @@ func TestKubeletConfigurationPathFields(t *testing.T) {
 
 	// ensure that kubeletConfigurationPathFields U kubeletConfigurationNonPathFields == allPrimitiveFieldPaths(KubeletConfiguration)
 	expect := sets.NewString().Union(kubeletConfigurationPathFieldPaths).Union(kubeletConfigurationNonPathFieldPaths)
-	result := allPrimitiveFieldPaths(t, reflect.TypeOf(&KubeletConfiguration{}), nil)
+	result := allPrimitiveFieldPaths(t, expect, reflect.TypeOf(&KubeletConfiguration{}), nil)
 	if !expect.Equal(result) {
 		// expected fields missing from result
 		missing := expect.Difference(result)
@@ -58,18 +58,26 @@ func TestKubeletConfigurationPathFields(t *testing.T) {
 	}
 }
 
-func allPrimitiveFieldPaths(t *testing.T, tp reflect.Type, path *field.Path) sets.String {
+// allPrimitiveFieldPaths returns the set of field paths in type `tp`, rooted at `path`.
+// It recursively descends into the definition of type `tp` accumulating paths to primitive leaf fields or paths in `skipRecurseList`.
+func allPrimitiveFieldPaths(t *testing.T, skipRecurseList sets.String, tp reflect.Type, path *field.Path) sets.String {
+	// if the current field path is in the list of paths we should not recurse into,
+	// return here rather than descending and accumulating child field paths
+	if pathStr := path.String(); len(pathStr) > 0 && skipRecurseList.Has(pathStr) {
+		return sets.NewString(pathStr)
+	}
+
 	paths := sets.NewString()
 	switch tp.Kind() {
 	case reflect.Ptr:
-		paths.Insert(allPrimitiveFieldPaths(t, tp.Elem(), path).List()...)
+		paths.Insert(allPrimitiveFieldPaths(t, skipRecurseList, tp.Elem(), path).List()...)
 	case reflect.Struct:
 		for i := 0; i < tp.NumField(); i++ {
 			field := tp.Field(i)
-			paths.Insert(allPrimitiveFieldPaths(t, field.Type, path.Child(field.Name)).List()...)
+			paths.Insert(allPrimitiveFieldPaths(t, skipRecurseList, field.Type, path.Child(field.Name)).List()...)
 		}
 	case reflect.Map, reflect.Slice:
-		paths.Insert(allPrimitiveFieldPaths(t, tp.Elem(), path.Key("*")).List()...)
+		paths.Insert(allPrimitiveFieldPaths(t, skipRecurseList, tp.Elem(), path.Key("*")).List()...)
 	case reflect.Interface:
 		t.Fatalf("unexpected interface{} field %s", path.String())
 	default:
@@ -97,6 +105,13 @@ type bar struct {
 
 	bars   []foo
 	barMap map[string]foo
+
+	skipRecurseStruct  foo
+	skipRecursePointer *foo
+	skipRecurseList1   []foo
+	skipRecurseList2   []foo
+	skipRecurseMap1    map[string]foo
+	skipRecurseMap2    map[string]foo
 }
 
 func TestAllPrimitiveFieldPaths(t *testing.T) {
@@ -109,8 +124,14 @@ func TestAllPrimitiveFieldPaths(t *testing.T) {
 		"fooptr.foo",
 		"bars[*].foo",
 		"barMap[*].foo",
+		"skipRecurseStruct",   // skip recursing a struct
+		"skipRecursePointer",  // skip recursing a struct pointer
+		"skipRecurseList1",    // skip recursing a list
+		"skipRecurseList2[*]", // skip recursing list items
+		"skipRecurseMap1",     // skip recursing a map
+		"skipRecurseMap2[*]",  // skip recursing map items
 	)
-	result := allPrimitiveFieldPaths(t, reflect.TypeOf(&bar{}), nil)
+	result := allPrimitiveFieldPaths(t, expect, reflect.TypeOf(&bar{}), nil)
 	if !expect.Equal(result) {
 		// expected fields missing from result
 		missing := expect.Difference(result)
@@ -233,14 +254,7 @@ var (
 		"ReadOnlyPort",
 		"RegistryBurst",
 		"RegistryPullQPS",
-		"ReservedMemory[*].Limits[*].Format",
+		"ReservedMemory",
-		"ReservedMemory[*].Limits[*].d.Dec.scale",
-		"ReservedMemory[*].Limits[*].d.Dec.unscaled.abs[*]",
-		"ReservedMemory[*].Limits[*].d.Dec.unscaled.neg",
-		"ReservedMemory[*].Limits[*].i.scale",
-		"ReservedMemory[*].Limits[*].i.value",
-		"ReservedMemory[*].Limits[*].s",
-		"ReservedMemory[*].NumaNode",
 		"ReservedSystemCPUs",
 		"RuntimeRequestTimeout.Duration",
 		"RunOnce",