Merge branch 'jv-simplify-badgateway' into 'master'

Simplify badgateway RoundTripper

See merge request gitlab-org/gitlab-workhorse!425

internal/badgateway/roundtripper.go

@@ -23,9 +23,13 @@ func NewRoundTripper(developmentMode bool, next http.RoundTripper) http.RoundTri
 	return &roundTripper{next: next, developmentMode: developmentMode}
 }
 
-func (t *roundTripper) RoundTrip(r *http.Request) (res *http.Response, err error) {
+func (t *roundTripper) RoundTrip(r *http.Request) (*http.Response, error) {
 	start := time.Now()
-	res, err = t.next.RoundTrip(r)
+
+	res, err := t.next.RoundTrip(r)
+	if err == nil {
+		return res, err
+	}
 
 	// httputil.ReverseProxy translates all errors from this
 	// RoundTrip function into 500 errors. But the most likely error
@@ -33,7 +37,6 @@ func (t *roundTripper) RoundTrip(r *http.Request) (res *http.Response, err error
 	// and administrators expect to see a 502 error. To show 502s
 	// instead of 500s we catch the RoundTrip error here and inject a
 	// 502 response.
-	if err != nil {
 	helper.LogError(
 		r,
 		&sentryError{fmt.Errorf("badgateway: failed after %.fs: %v", time.Since(start).Seconds(), err)},
@@ -44,7 +47,7 @@ func (t *roundTripper) RoundTrip(r *http.Request) (res *http.Response, err error
 		message = err.Error()
 	}
 
-		res = &http.Response{
+	injectedResponse := &http.Response{
 		StatusCode: http.StatusBadGateway,
 		Status:     http.StatusText(http.StatusBadGateway),
 
@@ -56,8 +59,7 @@ func (t *roundTripper) RoundTrip(r *http.Request) (res *http.Response, err error
 		Trailer:    make(http.Header),
 		Body:       ioutil.NopCloser(bytes.NewBufferString(message)),
 	}
-		res.Header.Set("Content-Type", "text/plain")
-		err = nil
-	}
-	return
+	injectedResponse.Header.Set("Content-Type", "text/plain")
+
+	return injectedResponse, nil
 }