close service ring buffers on Pebble shutdown

internals/overlord/servstate/handlers.go

@@ -223,9 +223,6 @@ func (m *ServiceManager) doStop(task *state.Task, tomb *tomb.Tomb) error {
 	if service == nil {
 		return nil
 	}
-	// Close the ringbuffer to signal to consumers (e.g. log forwarding) that
-	// there are no more logs coming.
-	defer service.logs.Close()
 
 	// Stop service: send SIGTERM, and if that doesn't stop the process in a
 	// short time, send SIGKILL.
@@ -284,6 +281,17 @@ func (m *ServiceManager) removeService(name string) {
 	m.servicesLock.Lock()
 	defer m.servicesLock.Unlock()
 
+	svc, svcExists := m.services[name]
+	if !svcExists {
+		return
+	}
+	if svc.logs != nil {
+		err := svc.logs.Close()
+		if err != nil {
+			logger.Noticef("Error closing service %q ring buffer: %v", name, err)
+		}
+	}
+
 	delete(m.services, name)
 }
 

internals/overlord/servstate/manager.go

@@ -88,6 +88,9 @@ func (m *ServiceManager) Stop() {
 	if err != nil {
 		logger.Noticef("Cannot stop child process reaper: %v", err)
 	}
+	for name := range m.services {
+		m.removeService(name)
+	}
 }
 
 // NotifyPlanChanged adds f to the list of functions that are called whenever