/*
Update the list of remote hosts with the specified hostname.
*/
func (otter *Otter) UpdateHost(hostname, previous string) (string, error) {
options := etcd.SetOptions{
TTL: 60 * time.Second,
}
now := time.Now().String()
if previous != "" {
options.PrevValue = previous
}
_, err := otter.etcdKeysApi.Set(context.Background(), fmt.Sprintf("/ping/%s", hostname), now, &options)
if err != nil {
return now, err
}
return now, nil
}
func Register(heartbeat time.Duration, ttl time.Duration) {
Hearbeat, TTL = heartbeat, ttl
// begin book keeping "THIS" montior unit
go func() {
var work ctx.Context
work, Cancel = ctx.WithCancel(ctx.Background())
client := NewDiscovery()
var (
iden = path.Join(RegisterPath, Advertise)
opts = etcd.SetOptions{TTL: ttl}
kAPI = etcd.NewKeysAPI(client)
f = log.Fields{"heartbeat": heartbeat, "ttl": ttl}
t = time.NewTicker(heartbeat)
)
defer t.Stop()
// Allow for implicit bootstrap on register
if err := upkeep(kAPI, iden, &opts); err != nil {
log.Error("1:", err)
} else {
log.WithFields(f).Info("uptime")
}
// Tick... Toc...
for {
select {
case <-t.C:
if err := upkeep(kAPI, iden, &opts); err != nil {
log.Error("2:", err)
opts.PrevExist = etcd.PrevIgnore
} else {
log.WithFields(f).Info("uptime")
opts.PrevExist = etcd.PrevExist
}
case <-work.Done():
log.WithFields(f).Info("abort")
return
}
}
}()
}