// 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 {
beIGs.Insert(beToIG.Group)
}
igLinks := sets.String{}
for _, igToBE := range igs {
igLinks.Insert(igToBE.SelfLink)
}
if beIGs.IsSuperset(igLinks) {
return nil
}
glog.Infof("Backend %v has a broken edge, expected igs %+v, current igs %+v",
be.Name, igLinks.List(), beIGs.List())
newBackends := []*compute.Backend{}
for _, b := range getBackendsForIGs(igs) {
if !beIGs.Has(b.Group) {
newBackends = append(newBackends, b)
}
}
be.Backends = append(be.Backends, newBackends...)
if err := b.cloud.UpdateBackendService(be); err != nil {
return err
}
return nil
}