fix(provider): guard down's stopContainer against the relay too

glours' review flagged the same bug class this PR already fixes for
start/restart: stopContainer (down.go) runs PreStop hooks
unconditionally, and runHook execs into the container -- which fails
against a shell-less relay. Guarded it the same way, with a regression
test.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Signed-off-by: Nicolas De Loof <[email protected]>

pkg/compose/down.go

@@ -311,7 +311,7 @@ func (s *composeService) stopContainer(ctx context.Context, service *types.Servi
 	eventName := getContainerProgressName(ctr)
 	s.events.On(newEvent(eventName, api.Working, api.StatusStopping))
 
-	if service != nil {
+	if service != nil && !isRelayContainer(ctr) {
 		for _, hook := range service.PreStop {
 			err := s.runHook(ctx, ctr, *service, hook, listener)
 			if err != nil {

pkg/compose/down_test.go

@@ -676,6 +676,27 @@ func TestDownHookContainerRemovalFailureIsNonFatal(t *testing.T) {
 	assert.NilError(t, err)
 }
 
+// A relay stands in for the service on the network but is a shell-less
+// scratch binary: pre_stop has no process inside it to act on. No
+// ExecCreate expectation is set: per newStartTestService, gomock fails the
+// test if the hook still runs.
+func TestStopContainerSkipsPreStopForRelay(t *testing.T) {
+	svc, apiClient, _ := newStartTestService(t)
+
+	service := types.ServiceConfig{
+		Name:    "db",
+		PreStop: []types.ServiceHook{{Command: types.ShellCommand{"quiesce"}}},
+	}
+	relay := serviceContainer("db", 1, container.StateRunning)
+	relay.Labels[compose.RelayLabel] = "abc123"
+
+	apiClient.EXPECT().ContainerStop(gomock.Any(), relay.ID, gomock.Any()).
+		Return(client.ContainerStopResult{}, nil)
+
+	err := svc.stopContainer(t.Context(), &service, relay, nil, nil)
+	assert.NilError(t, err)
+}
+
 // runningOneOff builds a RUNNING `compose run` container of the given service.
 func runningOneOff(service, id string) container.Summary {
 	c := testContainer(service, id, true)