Rotation log writer

This is log writer to support rotation.

Note: logs directory in library intended for testing purposes

Usage

Example

You can use RotateWriter as standard golang log writer or use as zerolog writer.

Example for zerolog case:

package main

import (
    "fmt"
    "os"
    "os/signal"
    "syscall"
    "time"

    "github.com/ilya1st/rotatewriter"
    "github.com/rs/zerolog"
)

func main() {
    // this is for test
    writer, err := rotatewriter.NewRotateWriter("./logs/test.log", 8)
    if err != nil {
        panic(err)
    }
    sighupChan := make(chan os.Signal, 1)
    signal.Notify(sighupChan, syscall.SIGHUP)
    go func() {
        for {
            _, ok := <-sighupChan
            if !ok {
                return
            }
            fmt.Println("Log rotation")
            writer.Rotate(nil)
        }
    }()
    logger := zerolog.New(writer).With().Timestamp().Logger()
    fmt.Println("Just run in another console and look into logs directory:\n$ killall -HUP rotateexample")
    for {
        logger.Info().Msg("test")
        time.Sleep(500 * time.Millisecond)
    }
}

rotatewriter.NewRotateWriter() arguments

First argument is full log filename.

Second argument - number of files to store.

If it's 0 - writer just reopen file. This is for cases you use logrotate instrument around your app

rotatewriter.Rotate()

You call it when you need rotation. It has specific locks do not run rotation twice in same moment. you may pass callback tu function to know rotation is ready.

rotatewriter.RotationInProgress()

You can determine is rotation operation in progress or not if you need

Why

This package was inspired by lumberjack - but there is an issue with blocking while log rotation and it's overloaded with features as size counting, gzip but I need just correctly handle reopen.

Install

go get github.com/ilya1st/rotatewriter