Proxying Accept-Encoding and Accept headers for /asis

img/loader/http.go

@@ -66,15 +66,17 @@ func (r *Http) Load(url string, ctx context.Context) (*img.Image, error) {
 	}
 
 	contentType := resp.Header.Get("Content-Type")
+	contentEncoding := resp.Header.Get("Content-Encoding")
 
 	result, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}
 
 	return &img.Image{
-		Id:       url,
-		Data:     result,
-		MimeType: contentType,
+		Id:              url,
+		Data:            result,
+		MimeType:        contentType,
+		ContentEncoding: contentEncoding,
 	}, nil
 }

img/service.go

@@ -193,7 +193,6 @@ func (r *Service) AsIs(resp http.ResponseWriter, req *http.Request) {
 	Log.Printf("Requested image %s as is\n", imgUrl)
 
 	var proxyHeaders = make(http.Header)
-
 	accept := req.Header.Get("Accept")
 	if len(accept) > 0 {
 		proxyHeaders.Add("Accept", accept)
@@ -202,17 +201,14 @@ func (r *Service) AsIs(resp http.ResponseWriter, req *http.Request) {
 	if len(acceptEncoding) > 0 {
 		proxyHeaders.Add("Accept-Encoding", acceptEncoding)
 	}
+
 	result, err := r.Loader.Load(imgUrl, NewContextWithHeaders(req.Context(), &proxyHeaders))
 
 	if err != nil {
 		sendError(resp, err)
 		return
 	}
 
-	if len(result.MimeType) > 0 {
-		resp.Header().Add("Content-Type", result.MimeType)
-	}
-
 	r.execOp(&Command{
 		Config: &TransformationConfig{
 			Src: &Image{
@@ -249,11 +245,15 @@ func (r *Service) getQueue() *Queue {
 
 // Adds Content-Length and Cache-Control headers
 func addHeaders(resp http.ResponseWriter, image *Image) {
+	headers := resp.Header()
 	if len(image.MimeType) != 0 {
-		resp.Header().Add("Content-Type", image.MimeType)
+		headers.Add("Content-Type", image.MimeType)
+	}
+	if len(image.ContentEncoding) != 0 {
+		headers.Add("Content-Encoding", image.ContentEncoding)
 	}
-	resp.Header().Add("Content-Length", strconv.Itoa(len(image.Data)))
-	resp.Header().Add("Cache-Control", fmt.Sprintf("public, max-age=%d", CacheTTL))
+	headers.Add("Content-Length", strconv.Itoa(len(image.Data)))
+	headers.Add("Cache-Control", fmt.Sprintf("public, max-age=%d", CacheTTL))
 }
 
 func getQueryParam(url *url.URL, name string) (string, bool) {

img/service_test.go

@@ -143,9 +143,10 @@ func (l *loaderMock) Load(url string, ctx context.Context) (*img.Image, error) {
 	case "http://site.com/img.svg":
 		if acceptEncoding, ok := img.HeaderFromContext(ctx); ok && acceptEncoding.Get("Accept-Encoding") == "gzip" {
 			return &img.Image{
-				Data:     []byte(ImgSrc),
-				MimeType: "svg/gzip",
-				Id:       url,
+				Data:            []byte(ImgSrc),
+				MimeType:        "svg/xml",
+				ContentEncoding: "gzip",
+				Id:              url,
 			}, nil
 		}
 	}
@@ -606,7 +607,8 @@ func TestService_AsIs(t *testing.T) {
 				test.Error(t,
 					test.Equal("public, max-age=86400", w.Header().Get("Cache-Control"), "Cache-Control header"),
 					test.Equal("3", w.Header().Get("Content-Length"), "Content-Length header"),
-					test.Equal("svg/gzip", w.Header().Get("Content-Type"), "Content-Type header"),
+					test.Equal("svg/xml", w.Header().Get("Content-Type"), "Content-Type header"),
+					test.Equal("gzip", w.Header().Get("Content-Encoding"), "Content-Encoding header"),
 					test.Equal("", w.Header().Get("Vary"), "No Vary header"),
 				)
 			},
@@ -695,6 +697,16 @@ func FuzzService_ResizeUrl(f *testing.F) {
 	})
 }
 
+func TestHeaderFromContext(t *testing.T) {
+	header, ok := img.HeaderFromContext(context.Background())
+	if header != nil {
+		t.Errorf("expected nil header")
+	}
+	if ok {
+		t.Errorf("expected ok to be false")
+	}
+}
+
 func createService(t *testing.T) *img.Service {
 	img.CacheTTL = 86400
 	s, err := img.NewService(&loaderMock{}, &resizerMock{}, 1)

img/types.go

@@ -6,6 +6,9 @@ type Image struct {
 	Id       string
 	Data     []byte
 	MimeType string
+	// Content encoding is a literally Content-Encoding header from the response
+	// because of the #32 (https://github.com/Pixboost/transformimgs/issues/32)
+	ContentEncoding string
 }
 
 // Info holds basic information about an image.

run.sh

@@ -2,11 +2,4 @@
 
 set -e
 
-# Fetching and installing all dependencies
-# and running server on port 8080. Using this
-# script to run the application inside docker
-# container.
-
-cd cmd/
-echo 'Running Application'
-go run main.go -imConvert=/usr/local/bin/convert -imIdentify=/usr/local/bin/identify $@
+go run cmd/main.go -imConvert=/usr/local/bin/convert -imIdentify=/usr/local/bin/identify $@

test.sh

@@ -10,6 +10,7 @@ go test $(go list -buildvcs=false ./... | grep -v '/vendor/') -v -bench . -bench
 go test -fuzz=FuzzCalculateTargetSizeForResize -fuzztime 30s ./img/processor/internal/
 go test -fuzz=FuzzCalculateTargetSizeForFit -fuzztime 30s ./img/processor/internal/
 go test -fuzz=FuzzHttp_LoadImg -fuzztime 30s ./img/loader/
+go test -fuzz=FuzzHttp_LoadCustomGlobalHeaders -fuzztime 30s ./img/loader/
 go test -fuzz=FuzzService_ResizeUrl -fuzztime 30s ./img/
 
 echo 'Running go vet'