func (d *discoverdWrapper) Register() (bool, error) {
log := logger.New("fn", "discoverd.Register")
log.Info("registering with service discovery")
hb, err := discoverd.AddServiceAndRegister(serviceName, d.addr)
if err != nil {
log.Error("error registering with service discovery", "err", err)
return false, err
}
shutdown.BeforeExit(func() { hb.Close() })
selfAddr := hb.Addr()
log = log.New("self.addr", selfAddr)
service := discoverd.NewService(serviceName)
var leaders chan *discoverd.Instance
var stream stream.Stream
connect := func() (err error) {
log.Info("connecting service leader stream")
leaders = make(chan *discoverd.Instance)
stream, err = service.Leaders(leaders)
if err != nil {
log.Error("error connecting service leader stream", "err", err)
}
return
}
if err := connect(); err != nil {
return false, err
}
go func() {
outer:
for {
for leader := range leaders {
if leader == nil {
// a nil leader indicates there are no instances for
// the service, ignore and wait for an actual leader
log.Warn("received nil leader event")
continue
}
log.Info("received leader event", "leader.addr", leader.Addr)
d.leader <- leader.Addr == selfAddr
}
log.Warn("service leader stream disconnected", "err", stream.Err())
for {
if err := connect(); err == nil {
continue outer
}
time.Sleep(100 * time.Millisecond)
}
}
}()
select {
case isLeader := <-d.leader:
return isLeader, nil
case <-time.After(30 * time.Second):
return false, errors.New("timed out waiting for current service leader")
}
}
func (d *discoverdWrapper) Register() bool {
log := d.logger.New("fn", "discoverd.Register")
var hb discoverd.Heartbeater
for {
var err error
log.Info("registering with service discovery")
hb, err = discoverd.AddServiceAndRegister(serviceName, ":"+os.Getenv("PORT"))
if err == nil {
break
}
log.Error("error registering with service discovery", "err", err)
time.Sleep(time.Second)
}
shutdown.BeforeExit(func() { hb.Close() })
selfAddr := hb.Addr()
log = log.New("self.addr", selfAddr)
service := discoverd.NewService(serviceName)
var leaders chan *discoverd.Instance
var stream stream.Stream
connect := func() (err error) {
log.Info("connecting service leader stream")
leaders = make(chan *discoverd.Instance)
stream, err = service.Leaders(leaders)
if err != nil {
log.Error("error connecting service leader stream", "err", err)
}
return
}
go func() {
for {
for {
if err := connect(); err == nil {
break
}
time.Sleep(100 * time.Millisecond)
}
for leader := range leaders {
if leader == nil {
// a nil leader indicates there are no instances for
// the service, ignore and wait for an actual leader
log.Warn("received nil leader event")
continue
}
log.Info("received leader event", "leader.addr", leader.Addr)
d.leader <- leader.Addr == selfAddr
}
log.Warn("service leader stream disconnected", "err", stream.Err())
}
}()
start := time.Now()
tick := time.Tick(30 * time.Second)
for {
select {
case isLeader := <-d.leader:
return isLeader
case <-tick:
log.Warn("still waiting for current service leader", "duration", time.Since(start))
}
}
}