From c10dd884c494734d12aceb41daaccd1d8da9356b Mon Sep 17 00:00:00 2001
From: Andrea Nodari <and.nodari@gmail.com>
Date: Fri, 9 Apr 2021 17:17:23 +0200
Subject: [PATCH] Drop managed fields entries with unknown fields

This is aligned to the behaviour of server-side apply on main resources.
---
 .../handlers/fieldmanager/scalehandler.go     | 13 ++++-
 .../fieldmanager/scalehandler_test.go         | 50 +++++++++++++++++++
 2 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/scalehandler.go b/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/scalehandler.go
index 4f7296b88ed..3b328ae9a54 100644
--- a/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/scalehandler.go
+++ b/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/scalehandler.go
@@ -68,7 +68,12 @@ func (h *ScaleHandler) ToSubresource() ([]metav1.ManagedFieldsEntry, error) {
 	f := fieldpath.ManagedFields{}
 	t := map[string]*metav1.Time{}
 	for manager, versionedSet := range managed.Fields() {
-		path := h.mappings[string(versionedSet.APIVersion())]
+		path, ok := h.mappings[string(versionedSet.APIVersion())]
+		// Drop the field if the APIVersion of the managed field is unknown
+		if !ok {
+			continue
+		}
+
 		if versionedSet.Set().Has(path) {
 			newVersionedSet := fieldpath.NewVersionedSet(
 				fieldpath.NewSet(replicasPathInScale),
@@ -104,7 +109,11 @@ func (h *ScaleHandler) ToParent(scaleEntries []metav1.ManagedFieldsEntry) ([]met
 
 	for manager, versionedSet := range parentFields {
 		// Get the main resource "replicas" path
-		path := h.mappings[string(versionedSet.APIVersion())]
+		path, ok := h.mappings[string(versionedSet.APIVersion())]
+		// Drop the field if the APIVersion of the managed field is unknown
+		if !ok {
+			continue
+		}
 
 		// If the parent entry does not have the replicas path, just keep it as it is
 		if !versionedSet.Set().Has(path) {
diff --git a/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/scalehandler_test.go b/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/scalehandler_test.go
index 291f32fb35b..ffed4839b1a 100644
--- a/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/scalehandler_test.go
+++ b/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/scalehandler_test.go
@@ -117,6 +117,19 @@ func TestTransformManagedFieldsToSubresource(t *testing.T) {
 				},
 			},
 		},
+		{
+			desc: "drops fields if the api version is unknown",
+			input: []metav1.ManagedFieldsEntry{
+				{
+					Manager:    "manager-1",
+					Operation:  metav1.ManagedFieldsOperationApply,
+					APIVersion: "apps/v10",
+					FieldsType: "FieldsV1",
+					FieldsV1:   &metav1.FieldsV1{Raw: []byte(`{"f:spec":{"f:replicas":{}}}`)},
+				},
+			},
+			expected: nil,
+		},
 	}
 
 	for _, test := range tests {
@@ -564,6 +577,43 @@ func TestTransformingManagedFieldsToParent(t *testing.T) {
 				},
 			},
 		},
+		{
+			desc: "drops other fields if the api version is unknown",
+			parent: []metav1.ManagedFieldsEntry{
+				{
+					Manager:    "test",
+					Operation:  metav1.ManagedFieldsOperationApply,
+					APIVersion: "apps/v1",
+					FieldsType: "FieldsV1",
+					FieldsV1:   &metav1.FieldsV1{Raw: []byte(`{"f:spec":{"f:replicas":{}}}`)},
+				},
+				{
+					Manager:    "another-manager",
+					Operation:  metav1.ManagedFieldsOperationApply,
+					APIVersion: "apps/v10",
+					FieldsType: "FieldsV1",
+					FieldsV1:   &metav1.FieldsV1{Raw: []byte(`{"f:spec":{"f:selector":{}}}`)},
+				},
+			},
+			subresource: []metav1.ManagedFieldsEntry{
+				{
+					Manager:    "scale",
+					Operation:  metav1.ManagedFieldsOperationUpdate,
+					APIVersion: "autoscaling/v1",
+					FieldsType: "FieldsV1",
+					FieldsV1:   &metav1.FieldsV1{Raw: []byte(`{"f:spec":{"f:replicas":{}}}`)},
+				},
+			},
+			expected: []metav1.ManagedFieldsEntry{
+				{
+					Manager:    "scale",
+					Operation:  metav1.ManagedFieldsOperationUpdate,
+					APIVersion: "apps/v1",
+					FieldsType: "FieldsV1",
+					FieldsV1:   &metav1.FieldsV1{Raw: []byte(`{"f:spec":{"f:replicas":{}}}`)},
+				},
+			},
+		},
 	}
 
 	for _, test := range tests {