pkg/logutil: add json log format (#626)

conf/config.toml

@@ -20,8 +20,21 @@ tso-save-interval = "3s"
 [log]
 level = "info"
 
-#[log.file]
+# log format, one of json, text, console
+#format = "text"
+
+# disable automatic timestamps in output
+#disable-timestamp = false
+
+# file logging
+[log.file]
 #filename = ""
+# max log file size in MB
+#max-size = 300
+# max log file keep days
+#max-days = 28
+# maximum number of old log files to retain
+#max-backups = 7
 
 [metric]
 # prometheus client push interval, set "0s" to disable prometheus.

pkg/logutil/log.go

@@ -30,23 +30,33 @@ import (
 const (
 	defaultLogTimeFormat = "2006/01/02 15:04:05"
 	defaultLogMaxSize    = 300 // MB
-	defaultLogMaxBackups = 3
-	defaultLogMaxAge     = 28 // days
+	defaultLogFormat     = "text"
 	defaultLogLevel      = log.InfoLevel
-
-	logDirMode = 0755
 )
 
 // FileLogConfig serializes file log related config in toml/json.
 type FileLogConfig struct {
+	// Log filename, leave empty to disable file log.
 	Filename string `toml:"filename" json:"filename"`
+	// Is log rotate enabled. TODO.
+	LogRotate bool `toml:"log-rotate" json:"log-rotate"`
+	// Max size for a single file, in MB.
+	MaxSize int `toml:"max-size" json:"max-size"`
+	// Max log keep days, default is never deleting.
+	MaxDays int `toml:"max-days" json:"max-days"`
+	// Maximum number of old log files to retain.
+	MaxBackups int `toml:"max-backups" json:"max-backups"`
 }
 
 // LogConfig serializes log related config in toml/json.
 type LogConfig struct {
 	// Log level.
 	Level string `toml:"level" json:"level"`
-	// Log file.
+	// Log format. one of json, text, or console.
+	Format string `toml:"format" json:"format"`
+	// Disable automatic timestamps in output.
+	DisableTimestamp bool `toml:"disable-timestamp" json:"disable-timestamp"`
+	// File log config.
 	File FileLogConfig `toml:"file" json:"file"`
 }
 
@@ -130,7 +140,9 @@ func stringToLogLevel(level string) log.Level {
 }
 
 // textFormatter is for compatability with ngaut/log
-type textFormatter struct{}
+type textFormatter struct {
+	DisableTimestamp bool
+}
 
 // Format implements logrus.Formatter
 func (f *textFormatter) Format(entry *log.Entry) ([]byte, error) {
@@ -140,9 +152,11 @@ func (f *textFormatter) Format(entry *log.Entry) ([]byte, error) {
 	} else {
 		b = &bytes.Buffer{}
 	}
-	b.WriteString(entry.Time.Format(defaultLogTimeFormat))
+	if !f.DisableTimestamp {
+		fmt.Fprintf(b, "%s ", entry.Time.Format(defaultLogTimeFormat))
+	}
 	if file, ok := entry.Data["file"]; ok {
-		fmt.Fprintf(b, " %s:%v:", file, entry.Data["line"])
+		fmt.Fprintf(b, "%s:%v:", file, entry.Data["line"])
 	}
 	fmt.Fprintf(b, " [%s] %s", entry.Level.String(), entry.Message)
 	for k, v := range entry.Data {
@@ -154,33 +168,48 @@ func (f *textFormatter) Format(entry *log.Entry) ([]byte, error) {
 	return b.Bytes(), nil
 }
 
-// setLogOutput sets output path for all logs.
-func setLogOutput(filename string) error {
-	// PD log
-	if st, err := os.Stat(filename); err == nil {
+func stringToLogFormatter(format string, disableTimestamp bool) log.Formatter {
+	switch strings.ToLower(format) {
+	case "text":
+		return &textFormatter{
+			DisableTimestamp: disableTimestamp,
+		}
+	case "json":
+		return &log.JSONFormatter{
+			TimestampFormat:  defaultLogTimeFormat,
+			DisableTimestamp: disableTimestamp,
+		}
+	case "console":
+		return &log.TextFormatter{
+			FullTimestamp:    true,
+			TimestampFormat:  defaultLogTimeFormat,
+			DisableTimestamp: disableTimestamp,
+		}
+	default:
+		return &textFormatter{}
+	}
+}
+
+// InitFileLog initializes file based logging options.
+func InitFileLog(cfg *FileLogConfig) error {
+	if st, err := os.Stat(cfg.Filename); err == nil {
 		if st.IsDir() {
 			return errors.New("can't use directory as log file name")
 		}
 	}
-	dir := path.Dir(filename)
-	err := os.MkdirAll(dir, logDirMode)
-	if err != nil {
-		return errors.Trace(err)
+	if cfg.MaxSize == 0 {
+		cfg.MaxSize = defaultLogMaxSize
 	}
 
 	// use lumberjack to logrotate
 	output := &lumberjack.Logger{
-		Filename:   filename,
-		MaxSize:    defaultLogMaxSize, // megabytes
-		MaxBackups: defaultLogMaxBackups,
-		MaxAge:     defaultLogMaxAge, // days
+		Filename:   cfg.Filename,
+		MaxSize:    cfg.MaxSize,
+		MaxBackups: cfg.MaxBackups,
+		MaxAge:     cfg.MaxDays,
 		LocalTime:  true,
 	}
 
-	if _, err := output.Write([]byte{}); err != nil {
-		return errors.Errorf("log file is not writable: %v", err)
-	}
-
 	log.SetOutput(output)
 	return nil
 }
@@ -189,7 +218,11 @@ func setLogOutput(filename string) error {
 func InitLogger(cfg *LogConfig) error {
 	log.SetLevel(stringToLogLevel(cfg.Level))
 	log.AddHook(&contextHook{})
-	log.SetFormatter(&textFormatter{})
+
+	if cfg.Format == "" {
+		cfg.Format = defaultLogFormat
+	}
+	log.SetFormatter(stringToLogFormatter(cfg.Format, cfg.DisableTimestamp))
 
 	// etcd log
 	capnslog.SetFormatter(&redirectFormatter{})
@@ -198,7 +231,7 @@ func InitLogger(cfg *LogConfig) error {
 		return nil
 	}
 
-	err := setLogOutput(cfg.File.Filename)
+	err := InitFileLog(&cfg.File)
 	if err != nil {
 		return errors.Trace(err)
 	}