Should log decider for http middleware

http/log/middleware.go

@@ -29,7 +29,7 @@ func (r *loggingResponseWriter) WriteHeader(statusCode int) {
 }
 
 // LoggingMiddleware provides log middleware that log request and response.
-func LoggingMiddleware(logger log.Logger, handler http.Handler) http.Handler {
+func LoggingMiddleware(logger log.Logger, handler http.Handler, opts options) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		startTime := time.Now()
 		md := newLogMetadata(r, startTime)
@@ -40,9 +40,13 @@ func LoggingMiddleware(logger log.Logger, handler http.Handler) http.Handler {
 
 		handler.ServeHTTP(lrw, r)
 
+		status := lrw.status
+		if !opts.ShouldLog(r, status) {
+			return
+		}
+
 		duration_ms := float32(time.Since(startTime).Nanoseconds()/1000) / 1000
 		size := lrw.size
-		status := lrw.status
 
 		// TODO(raymondwongso) research more about status in integration with grpc gateway, somehow status is 0
 		// for now, override to 200 assuming it is a successful request

http/log/options.go

@@ -5,7 +5,7 @@ import (
 )
 
 // Decider defines rules for surpressing log
-type Decider func(req *http.Request, err error) bool
+type Decider func(req *http.Request, status int) bool
 
 type options struct {
 	ShouldLog Decider
@@ -20,15 +20,15 @@ func DefaultOptions() options {
 
 // DefaultDecider returns always true decider
 func DefaultDecider() Decider {
-	return func(req *http.Request, err error) bool {
+	return func(req *http.Request, status int) bool {
 		return true
 	}
 }
 
 // SkipPrometheusDecider returns common skip prometheus /metric
 func SkipPrometheusDecider() Decider {
-	return func(req *http.Request, err error) bool {
-		if err == nil && req.URL.Path == "/metrics" {
+	return func(req *http.Request, status int) bool {
+		if status == 200 && req.URL.Path == "/metrics" {
 			return false
 		}
 		return true