[Add] custom time stamp format #1046 (#1066)

* [Add] custom time stamp format

* [Update] property name & default value & comment about custom logger

middleware/logger.go

@@ -26,6 +26,7 @@ type (
 		// - time_unix_nano
 		// - time_rfc3339
 		// - time_rfc3339_nano
+		// - time_custom
 		// - id (Request ID)
 		// - remote_ip
 		// - uri
@@ -46,7 +47,10 @@ type (
 		// Example "${remote_ip} ${status}"
 		//
 		// Optional. Default value DefaultLoggerConfig.Format.
-		Format string `yaml:"format"`
+		Format                string `yaml:"format"`
+
+		// Optional. Default value DefaultLoggerConfig.CustomTimeFormat.
+		CustomTimeFormat string `yaml:"custom_time_format"`
 
 		// Output is a writer where logs in JSON format are written.
 		// Optional. Default value os.Stdout.
@@ -66,6 +70,7 @@ var (
 			`"method":"${method}","uri":"${uri}","status":${status}, "latency":${latency},` +
 			`"latency_human":"${latency_human}","bytes_in":${bytes_in},` +
 			`"bytes_out":${bytes_out}}` + "\n",
+		CustomTimeFormat:"2006-01-02 15:04:05.00000",
 		Output:  os.Stdout,
 		colorer: color.New(),
 	}
@@ -126,6 +131,8 @@ func LoggerWithConfig(config LoggerConfig) echo.MiddlewareFunc {
 					return buf.WriteString(time.Now().Format(time.RFC3339))
 				case "time_rfc3339_nano":
 					return buf.WriteString(time.Now().Format(time.RFC3339Nano))
+				case "time_custom":
+					return buf.WriteString(time.Now().Format(config.CustomTimeFormat))
 				case "id":
 					id := req.Header.Get(echo.HeaderXRequestID)
 					if id == "" {

middleware/logger_test.go

@@ -9,8 +9,11 @@ import (
 	"strings"
 	"testing"
 
+	"encoding/json"
 	"github.com/labstack/echo"
 	"github.com/stretchr/testify/assert"
+	"time"
+	"unsafe"
 )
 
 func TestLogger(t *testing.T) {
@@ -137,3 +140,34 @@ func TestLoggerTemplate(t *testing.T) {
 		assert.True(t, strings.Contains(buf.String(), token) == present, "Case: "+token)
 	}
 }
+
+func TestLoggerCustomTimestamp(t *testing.T) {
+	buf := new(bytes.Buffer)
+	customTimeFormat := "2006-01-02 15:04:05.00000"
+	e := echo.New()
+	e.Use(LoggerWithConfig(LoggerConfig{
+		Format: `{"time":"${time_custom}","id":"${id}","remote_ip":"${remote_ip}","host":"${host}","user_agent":"${user_agent}",` +
+			`"method":"${method}","uri":"${uri}","status":${status}, "latency":${latency},` +
+			`"latency_human":"${latency_human}","bytes_in":${bytes_in}, "path":"${path}", "referer":"${referer}",` +
+			`"bytes_out":${bytes_out},"ch":"${header:X-Custom-Header}",` +
+			`"us":"${query:username}", "cf":"${form:username}", "session":"${cookie:session}"}` + "\n",
+		CustomTimeFormat: customTimeFormat,
+		Output:                buf,
+	}))
+
+	e.GET("/", func(c echo.Context) error {
+		return c.String(http.StatusOK, "custom time stamp test")
+	})
+
+	req := httptest.NewRequest(echo.GET, "/", nil)
+	rec := httptest.NewRecorder()
+	e.ServeHTTP(rec, req)
+
+	var objs map[string]*json.RawMessage
+	if err := json.Unmarshal([]byte(buf.String()), &objs); err != nil {
+		panic(err)
+	}
+	loggedTime := *(*string)(unsafe.Pointer(objs["time"]))
+	_, err := time.Parse(customTimeFormat, loggedTime)
+	assert.Error(t, err)
+}