// 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
}