New logger for the Traefik logs

cmd/traefik/logger.go

@@ -0,0 +1,90 @@
+package main
+
+import (
+	"io"
+	stdlog "log"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/natefinch/lumberjack"
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+	"github.com/sirupsen/logrus"
+	"github.com/traefik/traefik/v2/pkg/config/static"
+	"github.com/traefik/traefik/v2/pkg/logs"
+)
+
+func init() {
+	// hide the first logs before the setup of the logger.
+	zerolog.SetGlobalLevel(zerolog.ErrorLevel)
+}
+
+func setupLogger(staticConfiguration *static.Configuration) {
+	// configure log format
+	w := getLogWriter(staticConfiguration)
+
+	// configure log level
+	logLevel := getLogLevel(staticConfiguration)
+
+	zerolog.SetGlobalLevel(logLevel)
+
+	// create logger
+	logCtx := zerolog.New(w).With().Timestamp()
+	if logLevel <= zerolog.DebugLevel {
+		logCtx = logCtx.Caller()
+	}
+
+	log.Logger = logCtx.Logger()
+	zerolog.DefaultContextLogger = &log.Logger
+
+	// Global logrus replacement (related to lib like go-rancher-metadata, docker, etc.)
+	logrus.StandardLogger().Out = logs.NoLevel(log.Logger, zerolog.DebugLevel)
+
+	// configure default standard log.
+	stdlog.SetFlags(stdlog.Lshortfile | stdlog.LstdFlags)
+	stdlog.SetOutput(logs.NoLevel(log.Logger, zerolog.DebugLevel))
+}
+
+func getLogWriter(staticConfiguration *static.Configuration) io.Writer {
+	var w io.Writer = os.Stderr
+
+	if staticConfiguration.Log != nil && len(staticConfiguration.Log.FilePath) > 0 {
+		_, _ = os.Create(staticConfiguration.Log.FilePath)
+		w = &lumberjack.Logger{
+			Filename:   staticConfiguration.Log.FilePath,
+			MaxSize:    staticConfiguration.Log.MaxSize,
+			MaxBackups: staticConfiguration.Log.MaxBackups,
+			MaxAge:     staticConfiguration.Log.MaxAge,
+			Compress:   true,
+		}
+	}
+
+	if staticConfiguration.Log == nil || staticConfiguration.Log.Format != "json" {
+		w = zerolog.ConsoleWriter{
+			Out:        w,
+			TimeFormat: time.RFC3339,
+			NoColor:    staticConfiguration.Log != nil && (staticConfiguration.Log.NoColor || len(staticConfiguration.Log.FilePath) > 0),
+		}
+	}
+
+	return w
+}
+
+func getLogLevel(staticConfiguration *static.Configuration) zerolog.Level {
+	levelStr := "error"
+	if staticConfiguration.Log != nil && staticConfiguration.Log.Level != "" {
+		levelStr = strings.ToLower(staticConfiguration.Log.Level)
+	}
+
+	logLevel, err := zerolog.ParseLevel(strings.ToLower(levelStr))
+	if err != nil {
+		log.Error().Err(err).
+			Str("logLevel", levelStr).
+			Msg("Unspecified or invalid log level, setting the level to default (ERROR)...")
+
+		logLevel = zerolog.ErrorLevel
+	}
+
+	return logLevel
+}