ingress

type Backend interface {
	// Set new state of routing tables. All records must have unique domains.
	Set(ctx context.Context, records []Record) error
}

type BackendFunc func(ctx context.Context, records []Record) error

type ErrDomainUsed struct {
	LeaserGroup string
}

type Record struct {
	Domain    string   // unique reference to service.
	Addresses []string // host:port, could be multiple in case of scale factor > 1
	Group     string   // namespace, not used in routing
}