Add logger middleware template variables: ${time_unix_milli} and ${time_unix_micro} (#2206)

This patch introduces two template variables `${time_unix_milli}` and
`${time_unix_micro}` into the logger middleware.
Currently, there is no way to interpolate that UNIX milli and micro
seconds timestamp in a log entry, and go 1.17 or later runtime supports
the utility functions `time#UnixMilli()` and `time#UnixMicro()`
so this patch adds them as well.

see also: https://github.com/golang/go/issues/44196

Signed-off-by: moznion <moznion@mail.moznion.net>

middleware/logger.go

@@ -23,6 +23,8 @@ type (
 		// Tags to construct the logger format.
 		//
 		// - time_unix
+		// - time_unix_milli
+		// - time_unix_micro
 		// - time_unix_nano
 		// - time_rfc3339
 		// - time_rfc3339_nano
@@ -126,6 +128,12 @@ func LoggerWithConfig(config LoggerConfig) echo.MiddlewareFunc {
 				switch tag {
 				case "time_unix":
 					return buf.WriteString(strconv.FormatInt(time.Now().Unix(), 10))
+				case "time_unix_milli":
+					// go 1.17 or later, it supports time#UnixMilli()
+					return buf.WriteString(strconv.FormatInt(time.Now().UnixNano()/1000000, 10))
+				case "time_unix_micro":
+					// go 1.17 or later, it supports time#UnixMicro()
+					return buf.WriteString(strconv.FormatInt(time.Now().UnixNano()/1000, 10))
 				case "time_unix_nano":
 					return buf.WriteString(strconv.FormatInt(time.Now().UnixNano(), 10))
 				case "time_rfc3339":

middleware/logger_test.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"net/url"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -244,3 +245,49 @@ func BenchmarkLoggerWithConfig_withMapFields(b *testing.B) {
 		buf.Reset()
 	}
 }
+
+func TestLoggerTemplateWithTimeUnixMilli(t *testing.T) {
+	buf := new(bytes.Buffer)
+
+	e := echo.New()
+	e.Use(LoggerWithConfig(LoggerConfig{
+		Format: `${time_unix_milli}`,
+		Output: buf,
+	}))
+
+	e.GET("/", func(c echo.Context) error {
+		return c.String(http.StatusOK, "OK")
+	})
+
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+
+	rec := httptest.NewRecorder()
+	e.ServeHTTP(rec, req)
+
+	unixMillis, err := strconv.ParseInt(buf.String(), 10, 64)
+	assert.NoError(t, err)
+	assert.WithinDuration(t, time.Unix(unixMillis/1000, 0), time.Now(), 3*time.Second)
+}
+
+func TestLoggerTemplateWithTimeUnixMicro(t *testing.T) {
+	buf := new(bytes.Buffer)
+
+	e := echo.New()
+	e.Use(LoggerWithConfig(LoggerConfig{
+		Format: `${time_unix_micro}`,
+		Output: buf,
+	}))
+
+	e.GET("/", func(c echo.Context) error {
+		return c.String(http.StatusOK, "OK")
+	})
+
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+
+	rec := httptest.NewRecorder()
+	e.ServeHTTP(rec, req)
+
+	unixMicros, err := strconv.ParseInt(buf.String(), 10, 64)
+	assert.NoError(t, err)
+	assert.WithinDuration(t, time.Unix(unixMicros/1000000, 0), time.Now(), 3*time.Second)
+}