code: func GetIngressNetwork(s *store.MemoryStore) (*api.Network, error) {
  	var (
  		networks []*api.Network
  		err      error
  	)
  	s.View(func(tx store.ReadTx) {
  		networks, err = store.FindNetworks(tx, store.All)
  	})
  	if err != nil {
  		return nil, err
  	}
  	for _, n := range networks {
  		if IsIngressNetwork(n) {
  			return n, nil
  		}
  	}
  	return nil, ErrNoIngress
  }
docs: // GetIngressNetwork fetches the ingress network from store.
  // ErrNoIngress will be returned if the ingress network is not present,
  // nil otherwise. In case of any other failure in accessing the store,
  // the respective error will be reported as is.