Merge pull request #20 from naver/fix-freezed-tailer

fix the log tailer to ensure it drains all remaining logs without waiting

pkg/lobster/tailer/tail/tail.go

@@ -77,7 +77,7 @@ type Config struct {
 type Tail struct {
 	Filename  string
 	Lines     chan *Line
-	IsSending bool
+	IsTailing bool
 	Config
 
 	file   *os.File
@@ -233,9 +233,12 @@ func (tail *Tail) readLine() (string, error) {
 }
 
 func (tail *Tail) tailFileSync() {
+	defer func() { tail.IsTailing = false }()
 	defer tail.Done()
 	defer tail.close()
 
+	tail.IsTailing = true
+
 	if !tail.MustExist {
 		// deferred first open.
 		err := tail.reopen()
@@ -434,8 +437,6 @@ func (tail *Tail) sendLine(line string) bool {
 	now := time.Now()
 	lines := []string{line}
 
-	tail.IsSending = true
-	defer func() { tail.IsSending = false }()
 	// Split longer lines
 	if tail.MaxLineSize > 0 && len(line) > tail.MaxLineSize {
 		lines = util.PartitionString(line, tail.MaxLineSize)

pkg/lobster/tailer/tailer.go

@@ -33,7 +33,6 @@ import (
 const (
 	statusRunning status = 1
 	statusIdle    status = 2
-	drainWait            = time.Millisecond
 )
 
 type status int
@@ -178,15 +177,13 @@ func (t *Tailer) doStop() {
 func (t *Tailer) drain() {
 	t.tail.Kill(nil)
 
-	time.Sleep(drainWait)
-
 	select {
 	case <-t.LogChan:
 	default:
 		close(t.LogChan)
 	}
 
-	for t.tail.IsSending {
+	for t.tail.IsTailing {
 		select {
 		case <-t.tail.Lines:
 		default: