Example #1
// clusterSyncLoop observes running clusters changes, and apply all services to new added cluster
// and add dns records for the changes
func (s *ServiceController) clusterSyncLoop() {
	var servicesToUpdate []*cachedService
	// should we remove cache for cluster from ready to not ready? should remove the condition predicate if no
	clusters, err := s.clusterStore.ClusterCondition(getClusterConditionPredicate()).List()
	if err != nil {
		glog.Infof("Fail to get cluster list")
	newClusters := clustersFromList(&clusters)
	var newSet, increase sets.String
	newSet = sets.NewString(newClusters...)
	if newSet.Equal(s.knownClusterSet) {
		// The set of cluster names in the services in the federation hasn't changed, but we can retry
		// updating any services that we failed to update last time around.
		servicesToUpdate = s.updateDNSRecords(servicesToUpdate, newClusters)
	glog.Infof("Detected change in list of cluster names. New  set: %v, Old set: %v", newSet, s.knownClusterSet)
	increase = newSet.Difference(s.knownClusterSet)
	// do nothing when cluster is removed.
	if increase != nil {
		// Try updating all services, and save the ones that fail to try again next
		// round.
		servicesToUpdate = s.serviceCache.allServices()
		numServices := len(servicesToUpdate)
		for newCluster := range increase {
			glog.Infof("New cluster observed %s", newCluster)
			s.updateAllServicesToCluster(servicesToUpdate, newCluster)
		servicesToUpdate = s.updateDNSRecords(servicesToUpdate, newClusters)
		glog.Infof("Successfully updated %d out of %d DNS records to direct traffic to the updated cluster",
			numServices-len(servicesToUpdate), numServices)
	s.knownClusterSet = newSet
Example #2
// edgeHop checks the links of the given backend by executing an edge hop.
// It fixes broken links.
func (b *Backends) edgeHop(be *compute.BackendService, igs []*compute.InstanceGroup) error {
	beIGs := sets.String{}
	for _, beToIG := range be.Backends {
	igLinks := sets.String{}
	for _, igToBE := range igs {
	if igLinks.Equal(beIGs) {
		return nil
	glog.Infof("Backend %v has a broken edge, expected igs %+v, current igs %+v",
		be.Name, igLinks.List(), beIGs.List())
	be.Backends = getBackendsForIGs(igs)
	if err := b.cloud.UpdateBackendService(be); err != nil {
		return err
	return nil