feat: make log levels customizable (#20)

Co-authored-by: Giulio Ruggeri <[email protected]>

README.md

@@ -92,6 +92,13 @@ func main() {
     c.String(http.StatusOK, "pong "+fmt.Sprint(time.Now().Unix()))
   })
 
+  // Example custom log level.
+  r.GET("/debugonly", logger.SetLogger(
+    logger.WithDefaultLevel(zerolog.DebugLevel),
+  ), func(c *gin.Context) {
+    c.String(http.StatusOK, "pong "+fmt.Sprint(time.Now().Unix()))
+  })
+
   r.GET("/id", requestid.New(requestid.Config{
     Generator: func() string {
       return "foo-bar"

logger.go

@@ -47,6 +47,12 @@ type config struct {
 	// Output is a writer where logs are written.
 	// Optional. Default value is gin.DefaultWriter.
 	output io.Writer
+	// the log level used for request with status code < 400
+	defaultLevel zerolog.Level
+	// the log level used for request with status code between 400 and 499
+	clientErrorLevel zerolog.Level
+	// the log level used for request with status code >= 500
+	serverErrorLevel zerolog.Level
 }
 
 // WithLogger set custom logger func
@@ -85,11 +91,32 @@ func WithWriter(s io.Writer) Option {
 	}
 }
 
+func WithDefaultLevel(lvl zerolog.Level) Option {
+	return func(c *config) {
+		c.defaultLevel = lvl
+	}
+}
+
+func WithClientErrorLevel(lvl zerolog.Level) Option {
+	return func(c *config) {
+		c.clientErrorLevel = lvl
+	}
+}
+
+func WithServerErrorLevel(lvl zerolog.Level) Option {
+	return func(c *config) {
+		c.serverErrorLevel = lvl
+	}
+}
+
 // SetLogger initializes the logging middleware.
 func SetLogger(opts ...Option) gin.HandlerFunc {
 	l := &config{
-		logger: defaultLogger,
-		output: gin.DefaultWriter,
+		logger:           defaultLogger,
+		defaultLevel:     zerolog.InfoLevel,
+		clientErrorLevel: zerolog.WarnLevel,
+		serverErrorLevel: zerolog.ErrorLevel,
+		output:           gin.DefaultWriter,
 	}
 
 	// Loop through each option
@@ -143,16 +170,16 @@ func SetLogger(opts ...Option) gin.HandlerFunc {
 			switch {
 			case c.Writer.Status() >= http.StatusBadRequest && c.Writer.Status() < http.StatusInternalServerError:
 				{
-					logger.Warn().
+					logger.WithLevel(l.clientErrorLevel).
 						Msg(msg)
 				}
 			case c.Writer.Status() >= http.StatusInternalServerError:
 				{
-					logger.Error().
+					logger.WithLevel(l.serverErrorLevel).
 						Msg(msg)
 				}
 			default:
-				logger.Info().
+				logger.WithLevel(l.defaultLevel).
 					Msg(msg)
 			}
 		}

logger_test.go

@@ -118,3 +118,33 @@ func TestLoggerWithLogger(t *testing.T) {
 	performRequest(r, "GET", "/regexp02")
 	assert.NotContains(t, buffer.String(), "/regexp02")
 }
+
+func TestLoggerWithLevels(t *testing.T) {
+	buffer := new(bytes.Buffer)
+	gin.SetMode(gin.ReleaseMode)
+	r := gin.New()
+	r.Use(SetLogger(
+		WithWriter(buffer),
+		WithDefaultLevel(zerolog.DebugLevel),
+		WithClientErrorLevel(zerolog.ErrorLevel),
+		WithServerErrorLevel(zerolog.FatalLevel),
+	))
+	r.GET("/example", func(c *gin.Context) {})
+	r.POST("/example", func(c *gin.Context) {
+		c.String(http.StatusBadRequest, "ok")
+	})
+	r.PUT("/example", func(c *gin.Context) {
+		c.String(http.StatusBadGateway, "ok")
+	})
+
+	performRequest(r, "GET", "/example?a=100")
+	assert.Contains(t, buffer.String(), "DBG")
+
+	buffer.Reset()
+	performRequest(r, "POST", "/example?a=100")
+	assert.Contains(t, buffer.String(), "ERR")
+
+	buffer.Reset()
+	performRequest(r, "PUT", "/example?a=100")
+	assert.Contains(t, buffer.String(), "FTL")
+}