weave-scope/vendor/github.com/weaveworks/weave/common/logging.go

package common

import (
	"bytes"
	"fmt"
	"log"
	"strings"

	"github.com/sirupsen/logrus"
)

type textFormatter struct {
}

// Based off logrus.TextFormatter, which behaves completely
// differently when you don't want colored output
func (f *textFormatter) Format(entry *logrus.Entry) ([]byte, error) {
	b := &bytes.Buffer{}

	levelText := strings.ToUpper(entry.Level.String())[0:4]
	timeStamp := entry.Time.Format("2006/01/02 15:04:05.000000")
	if len(entry.Data) > 0 {
		fmt.Fprintf(b, "%s: %s %-44s ", levelText, timeStamp, entry.Message)
		for k, v := range entry.Data {
			fmt.Fprintf(b, " %s=%v", k, v)
		}
	} else {
		// No padding when there's no fields
		fmt.Fprintf(b, "%s: %s %s", levelText, timeStamp, entry.Message)
	}

	b.WriteByte('\n')
	return b.Bytes(), nil
}

var (
	standardTextFormatter = &textFormatter{}
)

var (
	Log *logrus.Logger
)

func init() {
	Log = logrus.New()
	Log.Formatter = standardTextFormatter
}

func SetLogLevel(levelname string) {
	level, err := logrus.ParseLevel(levelname)
	if err != nil {
		Log.Fatal(err)
	}
	Log.Level = level
}

func CheckFatal(e error) {
	if e != nil {
		Log.Fatal(e)
	}
}

func CheckWarn(e error) {
	if e != nil {
		Log.Warnln(e)
	}
}

// Adaptor type to go from Logrus to something expecting a standard library log.Logger
type logLogger struct {
	logger *logrus.Logger
}

// io.Writer interface
func (l logLogger) Write(p []byte) (n int, err error) {
	ln := len(p)
	// Strip a trailing newline, because logrus formatter adds one
	if ln > 0 && p[ln-1] == '\n' {
		p = p[:ln-1]
	}
	l.logger.Info(string(p))
	return ln, nil
}

func LogLogger() *log.Logger {
	return log.New(logLogger{Log}, "", 0)
}