func (instance *Instance) tailFile(name, filename string, stopCh chan bool, tracker storage.Tracker) {
var err error
var location *tail.SeekInfo
var limit int64
var shouldInitialize bool
pub := logyard.Broker.NewPublisherMust()
defer pub.Stop()
if tracker.IsChildNodeInitialized(instance.getShortDockerId(), filename) {
offset := tracker.GetFileCachedOffset(instance.getShortDockerId(), filename)
location = &tail.SeekInfo{offset, os.SEEK_SET}
} else {
limit, err = instance.getReadLimit(pub, name, filename)
location = &tail.SeekInfo{-limit, os.SEEK_END}
shouldInitialize = true
}
if err != nil {
log.Warn(err)
instance.SendTimelineEvent("WARN -- %v", err)
return
}
rateLimiter := GetConfig().GetLeakyBucket()
t, err := tail.TailFile(filename, tail.Config{
MaxLineSize: GetConfig().MaxRecordSize,
MustExist: true,
Follow: true,
Location: location,
ReOpen: false,
Poll: false,
RateLimiter: rateLimiter})
// IMPORTANT: this registration happens everytime app restarts
if shouldInitialize {
tracker.InitializeChildNode(instance.getShortDockerId(), filename, INITIAL_OFFSET)
}
if err != nil {
log.Warnf("Cannot tail file (%s); %s", filename, err)
instance.SendTimelineEvent("ERROR -- Cannot tail file (%s); %s", name, err)
return
}
instance.readFromTail(t, pub, name, stopCh, filename, tracker)
}
