Format timestamp in UTC with a precision of a milisecond

internal/logger/logger.go

@@ -21,6 +21,15 @@ var (
 	ProgName        string
 )
 
+type UTCFormatter struct {
+	defaultFormatter log.Formatter
+}
+
+func (f *UTCFormatter) Format(entry *log.Entry) ([]byte, error) {
+	entry.Time = entry.Time.UTC()
+	return f.defaultFormatter.Format(entry)
+}
+
 func Configure(cfg *config.Config) error {
 	mutex.Lock()
 	defer mutex.Unlock()
@@ -34,8 +43,20 @@ func Configure(cfg *config.Config) error {
 	}
 
 	log.SetOutput(logWriter)
+
 	if cfg.LogFormat == "json" {
-		log.SetFormatter(&log.JSONFormatter{})
+		log.SetFormatter(&UTCFormatter{
+			defaultFormatter: &log.JSONFormatter{
+				TimestampFormat: "2020-02-05 15:04:05.999Z",
+			},
+		})
+	} else {
+		log.SetFormatter(&UTCFormatter{
+			defaultFormatter: &log.TextFormatter{
+				TimestampFormat: "2020-02-05 15:04:05.999Z",
+				FullTimestamp:   true,
+			},
+		})
 	}
 
 	return nil

internal/logger/logger_test.go

+package logger
+
+import (
+  "fmt"
+  "github.com/sirupsen/logrus"
+  "github.com/sirupsen/logrus/hooks/test"
+  "github.com/stretchr/testify/assert"
+  "testing"
+)
+
+func TestSomething(t *testing.T){
+  logger, hook := test.NewNullLogger()
+
+  logger.Error("Helloerror")
+
+  assert.Equal(t, 1, len(hook.Entries))
+  assert.Equal(t, logrus.ErrorLevel, hook.LastEntry().Level)
+  assert.Equal(t, "Helloerror", hook.LastEntry().Message)
+
+  // TODO Check timestamp format here
+  assert.Equal(t, "", hook.LastEntry().Time)
+
+  fmt.Println(hook.LastEntry().Time)
+
+  hook.Reset()
+  assert.Nil(t, hook.LastEntry())
+}