Ejemplo n.º 1
0
// Replace the service's configuration, or update its list of backends.
// Replacing a configuration will shutdown the existing service, and start a
// new one, which will cause the listening socket to be temporarily
// unavailable.
func (s *ServiceRegistry) UpdateService(newCfg client.ServiceConfig) error {
	s.Lock()
	defer s.Unlock()

	log.Debug("Updating Service:", newCfg.Name)
	service, ok := s.svcs[newCfg.Name]
	if !ok {
		log.Debug("Service not found:", newCfg.Name)
		return ErrNoService
	}

	currentCfg := service.Config()
	newCfg.Merge(currentCfg)

	if err := service.UpdateConfig(newCfg); err != nil {
		return err
	}

	// Lots of looping here (including fetching the Config, but the cardinality
	// of Backends shouldn't be very large, and the default RoundRobin balancing
	// is much simpler with a slice.

	// we're going to update just the backends for this config
	// get a map of what's already running
	currentBackends := make(map[string]client.BackendConfig)
	for _, backendCfg := range currentCfg.Backends {
		currentBackends[backendCfg.Name] = backendCfg
	}

	// Keep existing backends when they have equivalent config.
	// Update changed backends, and add new ones.
	for _, newBackend := range newCfg.Backends {
		current, ok := currentBackends[newBackend.Name]
		if ok && current.Equal(newBackend) {
			log.Debugf("Backend %s/%s unchanged", service.Name, current.Name)
			// no change for this one
			delete(currentBackends, current.Name)
			continue
		}

		// we need to remove and re-add this backend
		log.Debugf("Updating Backend %s/%s", service.Name, newBackend.Name)
		service.remove(newBackend.Name)
		service.add(NewBackend(newBackend))

		delete(currentBackends, newBackend.Name)
	}

	// remove any left over backends
	for name := range currentBackends {
		log.Debugf("Removing Backend %s/%s", service.Name, name)
		service.remove(name)
	}

	if currentCfg.Equal(newCfg) {
		log.Debugf("Service Unchanged %s", service.Name)
		return nil
	}

	// replace error pages if there's any change
	if !reflect.DeepEqual(service.errPagesCfg, newCfg.ErrorPages) {
		log.Debugf("Updating ErrorPages")
		service.errPagesCfg = newCfg.ErrorPages
		service.errorPages.Update(newCfg.ErrorPages)
	}

	s.updateVHosts(service, filterEmpty(newCfg.VirtualHosts))

	return nil
}