Exclude GRPC from compress

middlewares/compress.go

@@ -3,6 +3,7 @@ package middlewares
 import (
 	"compress/gzip"
 	"net/http"
+	"strings"
 
 	"github.com/NYTimes/gziphandler"
 	"github.com/containous/traefik/log"
@@ -13,7 +14,12 @@ type Compress struct{}
 
 // ServerHTTP is a function used by Negroni
 func (c *Compress) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
-	gzipHandler(next).ServeHTTP(rw, r)
+	contentType := r.Header.Get("Content-Type")
+	if strings.HasPrefix(contentType, "application/grpc") {
+		next.ServeHTTP(rw, r)
+	} else {
+		gzipHandler(next).ServeHTTP(rw, r)
+	}
 }
 
 func gzipHandler(h http.Handler) http.Handler {

middlewares/compress_test.go

@@ -16,6 +16,7 @@ import (
 const (
 	acceptEncodingHeader  = "Accept-Encoding"
 	contentEncodingHeader = "Content-Encoding"
+	contentTypeHeader     = "Content-Type"
 	varyHeader            = "Vary"
 	gzipValue             = "gzip"
 )
@@ -81,6 +82,26 @@ func TestShouldNotCompressWhenNoAcceptEncodingHeader(t *testing.T) {
 	assert.EqualValues(t, rw.Body.Bytes(), fakeBody)
 }
 
+func TestShouldNotCompressWhenGRPC(t *testing.T) {
+	handler := &Compress{}
+
+	req := testhelpers.MustNewRequest(http.MethodGet, "http://localhost", nil)
+	req.Header.Add(acceptEncodingHeader, gzipValue)
+	req.Header.Add(contentTypeHeader, "application/grpc")
+
+	baseBody := generateBytes(gziphandler.DefaultMinSize)
+	next := func(rw http.ResponseWriter, r *http.Request) {
+		rw.Write(baseBody)
+	}
+
+	rw := httptest.NewRecorder()
+	handler.ServeHTTP(rw, req, next)
+
+	assert.Empty(t, rw.Header().Get(acceptEncodingHeader))
+	assert.Empty(t, rw.Header().Get(contentEncodingHeader))
+	assert.EqualValues(t, rw.Body.Bytes(), baseBody)
+}
+
 func TestIntegrationShouldNotCompress(t *testing.T) {
 	fakeCompressedBody := generateBytes(100000)
 	comp := &Compress{}