return a Content-Length with file requests

For some reason I forgot to do this or assumed it was done
automatically.

cdn-origin.go

@@ -21,6 +21,9 @@ import (
 // version is the current version of cdn-origin.
 const version = "0.2.0"
 
+// Default SeaweedFS fetch parameters.
+const defaultSeaweedFSQueryParameters = ""
+
 // HTTP header strings.
 const (
 	accept = "accept"
@@ -382,7 +385,7 @@ func requestHandler(ctx *fasthttp.RequestCtx) {
 		}
 
 		// TODO: ?thumbnail query parameter for images
-		statusCode, err := seaweed.Get(ctx, backend_file_id.String, "")
+		statusCode, contentSize, err := seaweed.Get(ctx, backend_file_id.String, defaultSeaweedFSQueryParameters)
 		if err != nil {
 			log.WithField("err", err).Warn("failed to retrieve file from SeaweedFS volume server")
 			ctx.SetStatusCode(fasthttp.StatusInternalServerError)
@@ -398,7 +401,9 @@ func requestHandler(ctx *fasthttp.RequestCtx) {
 			ctx.SetStatusCode(fasthttp.StatusInternalServerError)
 			ctx.SetContentType("text/plain; charset=utf8")
 			fmt.Fprint(ctx, "500 Internal Server Error")
+			return
 		}
+		ctx.Response.Header.SetContentLength(contentSize)
 
 	case 1: // redirect
 		if !dest_url.Valid {

weed/seaweed.go

@@ -55,10 +55,10 @@ func New(masterURI string, lookupTimeout time.Duration) *Seaweed {
 	}
 }
 
-func (s *Seaweed) Get(writer io.Writer, fid string, query string) (int, error) {
+func (s *Seaweed) Get(writer io.Writer, fid string, query string) (int, int, error) {
 	volumeURL := s.lookupVolume(strings.Split(fid, ",")[0])
 	if volumeURL == "" {
-		return 500, errors.New("failed to retrieve volume URL")
+		return fasthttp.StatusInternalServerError, 0, errors.New("failed to retrieve volume URL")
 	}
 	requestURL := volumeURL
 	if !strings.HasPrefix(requestURL, "http://") && !strings.HasPrefix(requestURL, "https://") {
@@ -85,15 +85,15 @@ func (s *Seaweed) Get(writer io.Writer, fid string, query string) (int, error) {
 	// Perform request
 	err := fasthttp.Do(req, res)
 	if err != nil {
-		return 0, err
+		return 0, 0, err
 	}
 	if res.StatusCode() == fasthttp.StatusOK {
 		if err := res.BodyWriteTo(writer); err != nil {
 			log.WithField("err", err).Warn("failed to set body writer for response")
-			return fasthttp.StatusInternalServerError, err
+			return fasthttp.StatusInternalServerError, 0, err
 		}
 	}
-	return fasthttp.StatusOK, err
+	return fasthttp.StatusOK, res.Header.ContentLength(), err
 }
 
 func (s *Seaweed) Ping() error {