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plugin/kubernetes: copy Labels in Pod.DeepCopyObject (#8415)

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* plugin/kubernetes: copy Labels in Pod.DeepCopyObject

Pod.DeepCopyObject built the copy field by field and left Labels out, so
every copy came back unlabelled. Every other object in this package copies
all of its fields; Pod was the only one missing any.

Labels feeds the kubernetes/client-label/<key> metadata, so anything that
reached a pod through a deep copy would see no labels at all rather than an
error. Nothing does today - DefaultProcessor stores the converted object
straight into the indexer without copying it, which is why this has not
surfaced - so this is a latent bug rather than a live one.

Clone the map instead of assigning it, so the copy does not alias the
original. maps.Clone returns nil for a nil map, so an unlabelled pod stays
unlabelled and a round trip does not turn a nil map into an empty one.

The test covers every runtime.Object in the package rather than just Pod,
and refuses to pass if a fixture leaves a field at its zero value. Adding a
field to any of these types therefore fails the test until the fixture sets
it, which is what makes the round-trip assertion cover the new field too.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Signed-off-by: Manuel Rüger <manuel@rueg.eu>

* plugin/kubernetes/object: deep copy the Service and ServiceImport ports

The deepcopy tests claimed a package-wide guarantee that a copy shares nothing
with its original, but only checked it for Pod and a hand-written Endpoints
value. Both api.ServicePort and mcs.ServicePort hold an AppProtocol *string, so
the elementwise copy(s1.Ports, s.Ports) in Service.DeepCopyObject and
ServiceImport.DeepCopyObject left the copy pointing at the original's string.
Mutating it through either side was visible from the other, and the tests still
passed.

Copy the ports with the generated DeepCopyInto so the copy owns everything it
can reach, and make the guarantee real: TestDeepCopyObjectIsDeep now runs over
every case in deepCopyCases, mutates every value reachable through a pointer,
slice, or map, and requires the copy to still equal a pristine fixture. A type
that gains a reference-bearing field is covered as soon as assertAllFieldsSet
forces the fixture to populate it, rather than needing a new hand-written case.

Failure messages render as JSON, because %+v prints an aliased pointer field as
an address and hides the value that actually differs.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Signed-off-by: Manuel Rüger <manuel@rueg.eu>

---------

Signed-off-by: Manuel Rüger <manuel@rueg.eu>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
This commit is contained in:
Manuel Rüger
2026-08-14 08:24:43 +02:00
committed by GitHub
parent 7b74c3368f
commit bc74540f54
4 changed files with 219 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

204
plugin/kubernetes/object/deepcopy_test.go Normal file
View File

@@ -0,0 +1,204 @@
package object
import (
"encoding/json"
"fmt"
"reflect"
"testing"
api "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/runtime"
mcs "sigs.k8s.io/mcs-api/pkg/apis/v1alpha1"
)
func ptrTo[T any](v T) *T { return &v }
// dump renders an object for a failure message. %+v prints an aliased pointer field as
// an address, which hides the value that actually differs, so render as JSON instead.
func dump(v any) string {
b, err := json.Marshal(v)
if err != nil {
return fmt.Sprintf("%+v", v)
}
return string(b)
}
// deepCopyCases holds one fully populated value of every type in this package that
// implements runtime.Object. Every exported field must be set to a non-zero value:
// assertAllFieldsSet enforces that, so a field added to one of these types fails here
// until it is set, which in turn makes TestDeepCopyObjectCopiesEveryField cover it.
func deepCopyCases() []struct {
name string
obj runtime.Object
} {
endpoints := &Endpoints{
Version: "1",
Name: "svc1-slice1",
Namespace: "testns",
Index: EndpointsKey("svc1", "testns"),
IndexIP: []string{"172.0.0.1"},
Subsets: []EndpointSubset{{
Addresses: []EndpointAddress{{
IP: "172.0.0.1",
Hostname: "ep1a",
NodeName: "node1",
TargetRefName: "pod1",
}},
Ports: []EndpointPort{{Port: 80, Name: "http", Protocol: "tcp"}},
}},
Zones: map[string]string{"172.0.0.1": "us-east-1a"},
}
return []struct {
name string
obj runtime.Object
}{
{"Pod", &Pod{
Version: "1",
PodIP: "10.244.0.1",
Name: "pod1",
Namespace: "testns",
Labels: map[string]string{"app": "nginx", "tier": "frontend"},
}},
{"Endpoints", endpoints},
{"MultiClusterEndpoints", &MultiClusterEndpoints{
Endpoints: *endpoints,
ClusterId: "cluster1",
}},
{"Service", &Service{
Version: "1",
Name: "svc1",
Namespace: "testns",
Index: ServiceKey("svc1", "testns"),
ClusterIPs: []string{"10.0.0.1"},
Type: api.ServiceTypeClusterIP,
ExternalName: "coredns.io",
Ports: []api.ServicePort{{
Name: "http", Protocol: api.ProtocolTCP, Port: 80,
// A pointer field, so a slice copy alone leaves it shared.
AppProtocol: ptrTo("kubernetes.io/h2c"),
}},
ExternalIPs: []string{"1.2.3.4"},
}},
{"ServiceImport", &ServiceImport{
Version: "1",
Name: "svc1",
Namespace: "testns",
Index: ServiceImportKey("svc1", "testns"),
ClusterIPs: []string{"10.0.0.1"},
Type: mcs.ClusterSetIP,
Ports: []mcs.ServicePort{{
Name: "http", Protocol: api.ProtocolTCP, Port: 80,
AppProtocol: ptrTo("kubernetes.io/h2c"),
}},
}},
{"Namespace", &Namespace{Version: "1", Name: "testns"}},
}
}
// assertAllFieldsSet reports any exported field left at its zero value. The embedded
// *Empty carries no data, so it is skipped.
func assertAllFieldsSet(t *testing.T, name string, obj any) {
t.Helper()
v := reflect.ValueOf(obj).Elem()
typ := v.Type()
for i := range typ.NumField() {
f := typ.Field(i)
if !f.IsExported() || f.Type == reflect.TypeFor[*Empty]() {
continue
}
if v.Field(i).IsZero() {
t.Errorf("%s: test fixture leaves field %q at its zero value; set it so DeepCopyObject is actually checked for it", name, f.Name)
}
}
}
func TestDeepCopyObjectCopiesEveryField(t *testing.T) {
for _, tc := range deepCopyCases() {
t.Run(tc.name, func(t *testing.T) {
assertAllFieldsSet(t, tc.name, tc.obj)
got := tc.obj.DeepCopyObject()
if !reflect.DeepEqual(tc.obj, got) {
t.Errorf("DeepCopyObject() dropped or altered a field\n got: %s\nwant: %s", dump(got), dump(tc.obj))
}
})
}
}
// mutateEverything changes every value in v that is reachable through a pointer,
// slice, or map. Anything the copy still shares with the original then shows up as a
// change to the copy. Values reached only by value are changed too; that is harmless,
// because the caller inspects the copy rather than the original.
func mutateEverything(v reflect.Value) {
switch v.Kind() {
case reflect.Pointer, reflect.Interface:
if !v.IsNil() {
mutateEverything(v.Elem())
}
case reflect.Slice, reflect.Array:
for i := range v.Len() {
mutateEverything(v.Index(i))
}
case reflect.Map:
for _, k := range v.MapKeys() {
// Map values are not addressable, so mutate a copy and write it back.
e := reflect.New(v.Type().Elem()).Elem()
e.Set(v.MapIndex(k))
mutateEverything(e)
v.SetMapIndex(k, e)
}
case reflect.Struct:
for i := range v.NumField() {
if v.Type().Field(i).IsExported() {
mutateEverything(v.Field(i))
}
}
case reflect.String:
if v.CanSet() {
v.SetString(v.String() + "-mutated")
}
case reflect.Bool:
if v.CanSet() {
v.SetBool(!v.Bool())
}
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
if v.CanSet() {
v.SetInt(v.Int() + 1)
}
}
}
// TestDeepCopyObjectIsDeep checks that a copy shares nothing with the original: after
// mutating every reference-reachable value in the original, the copy must still equal
// a pristine fixture. Driving this off deepCopyCases keeps the guarantee package-wide,
// so a type that gains a pointer, slice, or map field is covered here as soon as
// assertAllFieldsSet forces the fixture to populate it.
func TestDeepCopyObjectIsDeep(t *testing.T) {
for i, tc := range deepCopyCases() {
t.Run(tc.name, func(t *testing.T) {
// Rebuild per subtest: the fixtures deliberately share backing arrays
// (MultiClusterEndpoints is built from the same Endpoints value), so
// mutating one case would otherwise corrupt another.
obj := deepCopyCases()[i].obj
pristine := deepCopyCases()[i].obj
cp := obj.DeepCopyObject()
mutateEverything(reflect.ValueOf(obj))
if !reflect.DeepEqual(cp, pristine) {
t.Errorf("mutating the original was visible through the copy, so DeepCopyObject aliases it\n got: %s\nwant: %s", dump(cp), dump(pristine))
}
})
}
}
// Nil maps and slices must stay nil rather than becoming empty, so a round trip does
// not change how a value compares.
func TestDeepCopyObjectPreservesNilLabels(t *testing.T) {
pod := &Pod{Version: "1", PodIP: "10.244.0.1", Name: "pod1", Namespace: "testns"}
cp := pod.DeepCopyObject().(*Pod)
if cp.Labels != nil {
t.Errorf("nil Labels became %#v after a round trip", cp.Labels)
}
}