diff --git a/docs/handlers/api_test.go b/docs/handlers/api_test.go index 1e31477f7..6dc7a4228 100644 --- a/docs/handlers/api_test.go +++ b/docs/handlers/api_test.go @@ -263,6 +263,43 @@ func TestLayerAPI(t *testing.T) { checkResponse(t, "fetching layer bad digest", resp, http.StatusBadRequest) + // Cache headers + resp, err = http.Get(layerURL) + if err != nil { + t.Fatalf("unexpected error fetching layer: %v", err) + } + + checkResponse(t, "fetching layer", resp, http.StatusOK) + checkHeaders(t, resp, http.Header{ + "Content-Length": []string{fmt.Sprint(layerLength)}, + "Docker-Content-Digest": []string{layerDigest.String()}, + "ETag": []string{layerDigest.String()}, + "Cache-Control": []string{"max-age=86400"}, + }) + + // Matching etag, gives 304 + etag := resp.Header.Get("Etag") + req, err = http.NewRequest("GET", layerURL, nil) + if err != nil { + t.Fatalf("Error constructing request: %s", err) + } + req.Header.Set("If-None-Match", etag) + resp, err = http.DefaultClient.Do(req) + if err != nil { + t.Fatalf("Error constructing request: %s", err) + } + + checkResponse(t, "fetching layer with etag", resp, http.StatusNotModified) + + // Non-matching etag, gives 200 + req, err = http.NewRequest("GET", layerURL, nil) + if err != nil { + t.Fatalf("Error constructing request: %s", err) + } + req.Header.Set("If-None-Match", "") + resp, err = http.DefaultClient.Do(req) + checkResponse(t, "fetching layer with invalid etag", resp, http.StatusOK) + // Missing tests: // - Upload the same tarsum file under and different repository and // ensure the content remains uncorrupted. diff --git a/docs/storage/layerreader.go b/docs/storage/layerreader.go index ddca9741d..044dab09e 100644 --- a/docs/storage/layerreader.go +++ b/docs/storage/layerreader.go @@ -1,6 +1,7 @@ package storage import ( + "fmt" "net/http" "time" @@ -73,7 +74,31 @@ func (lr *layerReader) Handler(r *http.Request) (h http.Handler, err error) { } return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + // If the registry is serving this content itself, check + // the If-None-Match header and return 304 on match. Redirected + // storage implementations do the same. + + if etagMatch(r, lr.digest.String()) { + w.WriteHeader(http.StatusNotModified) + return + } + setCacheHeaders(w, 86400, lr.digest.String()) w.Header().Set("Docker-Content-Digest", lr.digest.String()) handlerFunc.ServeHTTP(w, r) }), nil } + +func etagMatch(r *http.Request, etag string) bool { + for _, headerVal := range r.Header["If-None-Match"] { + if headerVal == etag { + return true + } + } + return false +} + +func setCacheHeaders(w http.ResponseWriter, cacheAge int, etag string) { + w.Header().Set("ETag", etag) + w.Header().Set("Cache-Control", fmt.Sprintf("max-age=%d", cacheAge)) + +}