func watch(client etcd.Client, key string, stop chan struct{}) (res *etcd.Result) {
for res == nil {
select {
case <-stop:
log.V(1).Infof("Gracefully closing etcd watch loop: key=%s", key)
return
default:
req := &etcd.Watch{
Key: key,
WaitIndex: 0,
Recursive: true,
}
log.V(1).Infof("Creating etcd watcher: %v", req)
var err error
res, err = client.Wait(req, stop)
if err != nil {
log.Errorf("etcd watcher %v returned error: %v", req, err)
}
}
// Let's not slam the etcd server in the event that we know
// an unexpected error occurred.
time.Sleep(time.Second)
}
return
}
func watch(client etcd.Client, idx uint64, etcdchan chan *etcd.Result, key string, stop chan bool) {
for {
select {
case <-stop:
log.V(1).Infof("Gracefully closing etcd watch loop: key=%s", key)
return
default:
req := &etcd.Watch{
Key: key,
WaitIndex: idx,
Recursive: true,
}
log.V(1).Infof("Creating etcd watcher: %v", req)
resp, err := client.Wait(req, stop)
if err == nil {
if resp.Node != nil {
idx = resp.Node.ModifiedIndex + 1
}
etcdchan <- resp
continue
}
log.Errorf("etcd watcher %v returned error: %v", req, err)
etcdError, ok := err.(etcd.Error)
if !ok {
// Let's not slam the etcd server in the event that we know
// an unexpected error occurred.
time.Sleep(time.Second)
continue
}
switch etcdError.ErrorCode {
case etcd.ErrorEventIndexCleared:
// This is racy, but adding one to the last known index
// will help get this watcher back into the range of
// etcd's internal event history
idx = idx + 1
default:
// Let's not slam the etcd server in the event that we know
// an unexpected error occurred.
time.Sleep(time.Second)
}
}
}
}
