package storage import ( "fmt" "net/http" "time" "github.com/docker/distribution" "github.com/docker/distribution/context" "github.com/docker/distribution/registry/storage/driver" "github.com/opencontainers/go-digest" ) // TODO(stevvooe): This should configurable in the future. const blobCacheControlMaxAge = 365 * 24 * time.Hour // blobServer simply serves blobs from a driver instance using a path function // to identify paths and a descriptor service to fill in metadata. type blobServer struct { driver driver.StorageDriver statter distribution.BlobStatter pathFn func(dgst digest.Digest) (string, error) redirect bool // allows disabling URLFor redirects } func (bs *blobServer) ServeBlob(ctx context.Context, w http.ResponseWriter, r *http.Request, dgst digest.Digest) error { desc, err := bs.statter.Stat(ctx, dgst) if err != nil { return err } path, err := bs.pathFn(desc.Digest) if err != nil { return err } if bs.redirect { redirectURL, err := bs.driver.URLFor(ctx, path, map[string]interface{}{"method": r.Method}) switch err.(type) { case nil: // Redirect to storage URL. http.Redirect(w, r, redirectURL, http.StatusTemporaryRedirect) return err case driver.ErrUnsupportedMethod: // Fallback to serving the content directly. default: // Some unexpected error. return err } } br, err := newFileReader(ctx, bs.driver, path, desc.Size) if err != nil { return err } defer br.Close() w.Header().Set("ETag", fmt.Sprintf(`"%s"`, desc.Digest)) // If-None-Match handled by ServeContent w.Header().Set("Cache-Control", fmt.Sprintf("max-age=%.f", blobCacheControlMaxAge.Seconds())) if w.Header().Get("Docker-Content-Digest") == "" { w.Header().Set("Docker-Content-Digest", desc.Digest.String()) } if w.Header().Get("Content-Type") == "" { // Set the content type if not already set. w.Header().Set("Content-Type", desc.MediaType) } if w.Header().Get("Content-Length") == "" { // Set the content length if not already set. w.Header().Set("Content-Length", fmt.Sprint(desc.Size)) } http.ServeContent(w, r, desc.Digest.String(), time.Time{}, br) return nil }