Rolling file log.handler

[notzippy]

Here is a rolling file log handler I put together, feel free to use it. The only enhancement you may want to add is the option to delete files after x days or only have so many days of logs, and maybe choose your own format of the date. I can make a PR if you would think its useful

func RollingFile(path,filePrefix,fileSuffix string, fmtr log.Format) (log.Handler) {
    handler := &RollingFileHandler{FilePrefix:filePrefix,FileSuffix:fileSuffix,Path:path,Format:fmtr}
    e:= handler.Create()
    if e!=nil {
        panic("Unable to create logger for " + path +"/"+ filePrefix + fileSuffix)
    }
    return handler
}
type RollingFileHandler struct {
    Stream io.WriteCloser
    FormattedDay string
    Handler log.Handler
    Path,FilePrefix, FileSuffix string
    Format log.Format

}
func (h *RollingFileHandler) Close () error {
    if h.Stream!=nil {
        stream := h.Stream
        h.Stream=nil
        return stream.Close()
    }
    return nil
}
func (h *RollingFileHandler) Create () error {
    h.Close()
    formattedDay :=h.FilePrefix + time.Now().Format("2006-01-02") + h.FileSuffix
    h.FormattedDay = formattedDay
    path:=filepath.Join(h.Path,h.FormattedDay)
    f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
    if err != nil {
        return err
    }
    h.Stream = f
    h.Handler = log.StreamHandler(h.Stream,h.Format)
    return nil
}

func (h *RollingFileHandler) Log (r *log.Record) error {
    // Check the current day to see if the log should be closed
    formattedDay :=h.FilePrefix + time.Now().Format("2006-01-02") + h.FileSuffix
    if formattedDay!=h.FormattedDay || h.Stream==nil{
        err := h.Create()
        if err!=nil {
            return err
        }

    }
    h.Handler.Log(r)
    return nil
}

[ChrisHines]

I've been using gopkg.in/natefinch/lumberjack.v2, which implements io.Writer, wrapped with StreamHandler.

[notzippy]

:+1: LGTM