Some work on logger middleware

Signed-off-by: Vishal Rana <vr@labstack.com>

middleware/logger.go

@@ -4,24 +4,30 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"os"
 	"strconv"
 	"time"
 
 	"github.com/labstack/echo"
 	"github.com/labstack/gommon/color"
+	"github.com/mattn/go-isatty"
 	"github.com/valyala/fasttemplate"
 )
 
 type (
 	LoggerConfig struct {
 		Format   string
+		Output   io.Writer
 		template *fasttemplate.Template
+		color    *color.Color
 	}
 )
 
 var (
 	DefaultLoggerConfig = LoggerConfig{
 		Format: "time=${time_rfc3339}, remote_ip=${remote_ip}, method=${method}, path=${path}, status=${status}, response_time=${response_time}, size=${size}\n",
+		color:  color.New(),
+		Output: os.Stdout,
 	}
 )
 
@@ -31,13 +37,16 @@ func Logger() echo.MiddlewareFunc {
 
 func LoggerFromConfig(config LoggerConfig) echo.MiddlewareFunc {
 	config.template = fasttemplate.New(config.Format, "${", "}")
+	config.color = color.New()
+	if w, ok := config.Output.(*os.File); ok && !isatty.IsTerminal(w.Fd()) {
+		config.color.Disable()
+	}
 
 	return func(next echo.Handler) echo.Handler {
 		return echo.HandlerFunc(func(c echo.Context) (err error) {
 			req := c.Request()
 			res := c.Response()
 			remoteAddr := req.RemoteAddress()
-			output := c.Logger().Output()
 
 			if ip := req.Header().Get(echo.XRealIP); ip != "" {
 				remoteAddr = ip
@@ -71,7 +80,7 @@ func LoggerFromConfig(config LoggerConfig) echo.MiddlewareFunc {
 				status = color.Cyan(n)
 			}
 
-			_, err = config.template.ExecuteFunc(output, func(w io.Writer, tag string) (int, error) {
+			_, err = config.template.ExecuteFunc(config.Output, func(w io.Writer, tag string) (int, error) {
 				switch tag {
 				case "time_rfc3339":
 					return w.Write([]byte(time.Now().Format(time.RFC3339)))

middleware/logger_test.go

@@ -65,17 +65,17 @@ func TestLoggerIPAddress(t *testing.T) {
 	// With X-Real-IP
 	req.Header().Add(echo.XRealIP, ip)
 	h.Handle(c)
-	assert.Contains(t, buf.String(), ip)
+	assert.Contains(t, ip, buf.String())
 
 	// With X-Forwarded-For
 	buf.Reset()
 	req.Header().Del(echo.XRealIP)
 	req.Header().Add(echo.XForwardedFor, ip)
 	h.Handle(c)
-	assert.Contains(t, buf.String(), ip)
+	assert.Contains(t, ip, buf.String())
 
 	// with req.RemoteAddr
 	buf.Reset()
 	h.Handle(c)
-	assert.Contains(t, buf.String(), ip)
+	assert.Contains(t, ip, buf.String())
 }