adjust time format in logs to UTC

main.go

@@ -110,9 +110,10 @@ var (
 	dataDir             string
 	logDir              string // Custom log directory (default "")
 	logOutput           struct {
-		Color   bool
-		Console bool
-		File    bool
+		Color      bool
+		Console    bool
+		File       bool
+		TimeFormat string
 	}
 	ownAddress               string
 	bindAddress              string
@@ -205,6 +206,8 @@ func init() {
 	pf.BoolVar(&logOutput.Console, "log.console", true, "Send log output to console")
 	pf.BoolVar(&logOutput.File, "log.file", true, "Send log output to file")
 	pf.BoolVar(&logOutput.Color, "log.color", defaultLogColor, "Colorize the log output")
+	pf.StringVar(&logOutput.TimeFormat, "log.time-format", "local-datestring",
+		"Time format to use in logs. Possible values: 'local-datestring' (default), 'utc-datestring'")
 	pf.StringVar(&logDir, "log.dir", getEnvVar("LOG_DIR", ""), "Custom log file directory.")
 	f.IntVar(&logRotateFilesToKeep, "log.rotate-files-to-keep", defaultLogRotateFilesToKeep, "Number of files to keep when rotating log files")
 	f.DurationVar(&logRotateInterval, "log.rotate-interval", defaultLogRotateInterval, "Time between log rotations (0 disables log rotation)")
@@ -514,9 +517,15 @@ func cmdMainRun(cmd *cobra.Command, args []string) {
 // configureLogging configures the log object according to command line arguments.
 func configureLogging(consoleOnly bool) {
 	logOpts := logging.LoggerOutputOptions{
-		Stderr: logOutput.Console,
-		Color:  logOutput.Color,
+		Stderr:     logOutput.Console,
+		Color:      logOutput.Color,
+		TimeFormat: logging.TimeFormatLocal,
 	}
+
+	if logOutput.TimeFormat == "utc-datestring" {
+		logOpts.TimeFormat = logging.TimeFormatUTC
+	}
+
 	if logOutput.File && !consoleOnly {
 		if logDir != "" {
 			logOpts.LogFile = filepath.Join(logDir, logFileName)

pkg/logging/logger.go

@@ -29,10 +29,18 @@ import (
 	"os"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/rs/zerolog"
 )
 
+type TimeFormat int
+
+const (
+	TimeFormatLocal TimeFormat = 0
+	TimeFormatUTC   TimeFormat = 1
+)
+
 var (
 	// The defaultLevels list is used during development to increase the
 	// default level for components that we care a little less about.
@@ -72,14 +80,14 @@ type loggingService struct {
 }
 
 type LoggerOutputOptions struct {
-	Color   bool   // Produce colored logs
-	JSON    bool   // Project JSON messages
-	Stderr  bool   // Write logs to stderr
-	LogFile string // Path of file to write to
+	Color      bool       // Produce colored logs
+	TimeFormat TimeFormat // Instructs how to print time in logs
+	Stderr     bool       // Write logs to stderr
+	LogFile    string     // Path of file to write to
 }
 
 func configureLogger(lg zerolog.ConsoleWriter) zerolog.ConsoleWriter {
-	lg.TimeFormat = "2006-01-02T15:04:05-07:00"
+	lg.TimeFormat = time.RFC3339
 
 	lg.FormatLevel = func(i interface{}) string {
 		return fmt.Sprintf("|%s|", strings.ToUpper(fmt.Sprintf("%s", i)))
@@ -93,31 +101,32 @@ func NewRootLogger(options LoggerOutputOptions) (zerolog.Logger, func()) {
 	var writers []io.Writer
 	var errors []error
 	var rotate func()
+
+	if options.TimeFormat == TimeFormatUTC {
+		zerolog.TimestampFunc = func() time.Time {
+			return time.Now().UTC()
+		}
+	}
+
 	if options.LogFile != "" {
 		fileWriter, err := newRotatingWriter(options.LogFile)
 		if err != nil {
 			errors = append(errors, err)
 			options.Stderr = true
 		} else {
 			rotate = func() { fileWriter.Rotate() }
-			writer := io.Writer(fileWriter)
-			if !options.JSON {
-				writer = configureLogger(zerolog.ConsoleWriter{
-					Out:     fileWriter,
-					NoColor: true,
-				})
-			}
+			writer := configureLogger(zerolog.ConsoleWriter{
+				Out:     fileWriter,
+				NoColor: true,
+			})
 			writers = append(writers, writer)
 		}
 	}
 	if options.Stderr {
-		writer := io.Writer(os.Stderr)
-		if !options.JSON {
-			writer = configureLogger(zerolog.ConsoleWriter{
-				Out:     writer,
-				NoColor: !options.Color,
-			})
-		}
+		writer := configureLogger(zerolog.ConsoleWriter{
+			Out:     os.Stderr,
+			NoColor: !options.Color,
+		})
 		writers = append(writers, writer)
 	}