excluding directories before opening file for writing

client/driver/logs.go

@@ -27,6 +27,10 @@ func NewLogRotator(path string, fileName string, maxFiles int, fileSize int64) (
 	logFileIdx := 0
 	for _, f := range files {
 		if strings.HasPrefix(f.Name(), fileName) {
+			if f.IsDir() {
+				logFileIdx += 1
+				continue
+			}
 			fileIdx := strings.TrimPrefix(f.Name(), fmt.Sprintf("%s.", fileName))
 			n, err := strconv.Atoi(fileIdx)
 			if err != nil {
@@ -51,6 +55,12 @@ func (l *LogRotator) Start(r io.Reader) error {
 	buf := make([]byte, 32*1024)
 	for {
 		logFileName := filepath.Join(l.path, fmt.Sprintf("%s.%d", l.fileName, l.logFileIdx))
+		if f, err := os.Stat(logFileName); err == nil {
+			if f.IsDir() {
+				l.logFileIdx += 1
+				continue
+			}
+		}
 		f, err := os.OpenFile(logFileName, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
 		if err != nil {
 			return err

client/driver/logs_test.go

@@ -152,3 +152,50 @@ func TestLogRotator_StartFromEmptyDir(t *testing.T) {
 	}
 
 }
+
+func TestLogRotator_SetPathAsFile(t *testing.T) {
+	path := "/tmp/tmplogrator"
+	defer os.RemoveAll(path)
+	if _, err := os.Create(path); err != nil {
+		t.Fatalf("test setup problem: %v", err)
+	}
+
+	_, err := NewLogRotator(path, "redis.stdout", 10, 10)
+	if err == nil {
+		t.Fatal("expected error")
+	}
+}
+
+func TestLogRotator_ExcludeDirs(t *testing.T) {
+	path := "/tmp/tmplogrator"
+	defer os.RemoveAll(path)
+	if err := os.Mkdir(path, os.ModeDir|os.ModePerm); err != nil {
+		t.Fatalf("test setup err: %v", err)
+	}
+	if err := os.Mkdir(filepath.Join(path, "redis.stdout.0"), os.ModeDir|os.ModePerm); err != nil {
+		t.Fatalf("test setup err: %v", err)
+	}
+
+	l, err := NewLogRotator(path, "redis.stdout", 10, 6)
+	if err != nil {
+		t.Fatalf("test setup err: %v", err)
+	}
+
+	r, w := io.Pipe()
+	go func() {
+		w.Write([]byte("fg"))
+		w.Close()
+	}()
+	err = l.Start(r)
+	if err != nil && err != io.EOF {
+		t.Fatalf("Failure in logrotator start %v", err)
+	}
+
+	finfo, err := os.Stat("/tmp/tmplogrator/redis.stdout.1")
+	if err != nil {
+		t.Fatal("expected rotator to create redis.stdout.1")
+	}
+	if finfo.Size() != 2 {
+		t.Fatalf("expected size: %v, actual: %v", 2, finfo.Size())
+	}
+}