Handle unstructured objects correctly in IgnoreManagedFieldsTimestampsTransformer

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/equality.go

@@ -28,6 +28,7 @@ import (
 	"k8s.io/apimachinery/pkg/api/equality"
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/conversion"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apiserver/pkg/endpoints/metrics"
@@ -51,7 +52,7 @@ func getAvoidTimestampEqualities() conversion.Equalities {
 		}
 
 		var eqs = equality.Semantic.Copy()
-		err := eqs.AddFunc(
+		err := eqs.AddFuncs(
 			func(a, b metav1.ManagedFieldsEntry) bool {
 				// Two objects' managed fields are equivalent if, ignoring timestamp,
 				//	the objects are deeply equal.
@@ -59,6 +60,14 @@ func getAvoidTimestampEqualities() conversion.Equalities {
 				b.Time = nil
 				return reflect.DeepEqual(a, b)
 			},
+			func(a, b unstructured.Unstructured) bool {
+				// Check if the managed fields are equal by converting to structured types and leveraging the above
+				// function, then, ignoring the managed fields, equality check the rest of the unstructured data.
+				if !avoidTimestampEqualities.DeepEqual(a.GetManagedFields(), b.GetManagedFields()) {
+					return false
+				}
+				return equalIgnoringValueAtPath(a.Object, b.Object, []string{"metadata", "managedFields"})
+			},
 		)
 
 		if err != nil {
@@ -70,6 +79,35 @@ func getAvoidTimestampEqualities() conversion.Equalities {
 	return avoidTimestampEqualities
 }
 
+func equalIgnoringValueAtPath(a, b any, path []string) bool {
+	if len(path) == 0 { // found the value to ignore
+		return true
+	}
+	aMap, aOk := a.(map[string]any)
+	bMap, bOk := b.(map[string]any)
+	if !aOk || !bOk {
+		return !avoidTimestampEqualities.DeepEqual(a, b)
+	}
+	if len(aMap) != len(bMap) {
+		return false
+	}
+	pathHead := path[0]
+	for k, aVal := range aMap {
+		bVal, ok := bMap[k]
+		if !ok {
+			return false
+		}
+		if k == pathHead {
+			if !equalIgnoringValueAtPath(aVal, bVal, path[1:]) {
+				return false
+			}
+		} else if !avoidTimestampEqualities.DeepEqual(aVal, bVal) {
+			return false
+		}
+	}
+	return true
+}
+
 // IgnoreManagedFieldsTimestampsTransformer reverts timestamp updates
 // if the non-managed parts of the object are equivalent
 func IgnoreManagedFieldsTimestampsTransformer(

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/equality_test.go

@@ -0,0 +1,173 @@
+/*
+Copyright 20214The Kubernetes 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 fieldmanager
+
+import "testing"
+
+func TestEqualIgnoringFieldValueAtPath(t *testing.T) {
+	cases := []struct {
+		name string
+		a, b map[string]any
+		want bool
+	}{
+		{
+			name: "identical objects",
+			a: map[string]any{
+				"metadata": map[string]any{
+					"labels":        map[string]any{"env": "dev"},
+					"managedFields": []any{},
+				},
+				"spec": map[string]any{
+					"field": "value",
+				},
+			},
+			b: map[string]any{
+				"metadata": map[string]any{
+					"labels":        map[string]any{"env": "dev"},
+					"managedFields": []any{},
+				},
+				"spec": map[string]any{
+					"field": "value",
+				},
+			},
+			want: true,
+		},
+		{
+			name: "different metadata label value",
+			a: map[string]any{
+				"metadata": map[string]any{
+					"labels":        map[string]any{"env": "dev"},
+					"managedFields": []any{},
+				},
+				"spec": map[string]any{
+					"field": "value",
+				},
+			},
+			b: map[string]any{
+				"metadata": map[string]any{
+					"labels":        map[string]any{"env": "prod"},
+					"managedFields": []any{},
+				},
+				"spec": map[string]any{
+					"field": "value",
+				},
+			},
+			want: false,
+		},
+		{
+			name: "different spec value",
+			a: map[string]any{
+				"metadata": map[string]any{
+					"labels":        map[string]any{"env": "dev"},
+					"managedFields": []any{},
+				},
+				"spec": map[string]any{
+					"field": "value1",
+				},
+			},
+			b: map[string]any{
+				"metadata": map[string]any{
+					"labels":        map[string]any{"env": "dev"},
+					"managedFields": []any{},
+				},
+				"spec": map[string]any{
+					"field": "value2",
+				},
+			},
+			want: false,
+		},
+		{
+			name: "extra spec fields in object a",
+			a: map[string]any{
+				"metadata": map[string]any{
+					"labels":        map[string]any{"env": "dev"},
+					"managedFields": []any{},
+				},
+				"spec": map[string]any{
+					"field":      "value1",
+					"otherField": "other",
+				},
+			},
+			b: map[string]any{
+				"metadata": map[string]any{
+					"labels":        map[string]any{"env": "dev"},
+					"managedFields": []any{},
+				},
+				"spec": map[string]any{
+					"field": "value1",
+				},
+			},
+			want: false,
+		},
+		{
+			name: "different spec field in object b",
+			a: map[string]any{
+				"metadata": map[string]any{
+					"labels":        map[string]any{"env": "dev"},
+					"managedFields": []any{},
+				},
+				"spec": map[string]any{
+					"field": "value1",
+				},
+			},
+			b: map[string]any{
+				"metadata": map[string]any{
+					"labels":        map[string]any{"env": "dev"},
+					"managedFields": []any{},
+				},
+				"spec": map[string]any{
+					"field":      "value1",
+					"otherField": "other",
+				},
+			},
+			want: false,
+		},
+		{
+			name: "different managed fields should be ignored",
+			a: map[string]any{
+				"metadata": map[string]any{
+					"labels":        map[string]any{"env": "dev"},
+					"managedFields": []any{map[string]any{"manager": "client1"}},
+				},
+				"spec": map[string]any{
+					"field": "value",
+				},
+			},
+			b: map[string]any{
+				"metadata": map[string]any{
+					"labels":        map[string]any{"env": "dev"},
+					"managedFields": []any{map[string]any{"manager": "client2"}},
+				},
+				"spec": map[string]any{
+					"field": "value",
+				},
+			},
+			want: true,
+		},
+	}
+
+	path := []string{"metadata", "managedFields"}
+
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			actual := equalIgnoringValueAtPath(c.a, c.b, path)
+			if actual != c.want {
+				t.Error("Expected equality check to return ", c.want, ", but got ", actual)
+			}
+		})
+	}
+}