Merge pull request #894 from haoming29/metalink-for-origin

Add Metalink for redirect to origin

director/redirect.go

@@ -352,6 +352,12 @@ func redirectToOrigin(ginCtx *gin.Context) {
 		ginCtx.String(http.StatusNotFound, "There are currently no origins exporting the provided namespace prefix\n")
 		return
 	}
+	// if err != nil, depth == 0, which is the default value for depth
+	// so we can use it as the value for the header even with err
+	depth, err := getLinkDepth(reqPath, namespaceAd.Path)
+	if err != nil {
+		log.Errorf("Failed to get depth attribute for the redirecting request to %q, with best match namespace prefix %q", reqPath, namespaceAd.Path)
+	}
 
 	originAds, err = sortServers(ipAddr, originAds)
 	if err != nil {
@@ -360,8 +366,20 @@ func redirectToOrigin(ginCtx *gin.Context) {
 		return
 	}
 
-	var colUrl string
+	linkHeader := ""
+	first := true
+	for idx, ad := range originAds {
+		if first {
+			first = false
+		} else {
+			linkHeader += ", "
+		}
+		redirectURL := getRedirectURL(reqPath, ad, !namespaceAd.PublicRead)
+		linkHeader += fmt.Sprintf(`<%s>; rel="duplicate"; pri=%d; depth=%d`, redirectURL.String(), idx+1, depth)
+	}
+	ginCtx.Writer.Header()["Link"] = []string{linkHeader}
 
+	var colUrl string
 	if namespaceAd.PublicRead {
 		colUrl = originAds[0].URL.String()
 	} else {

xrootd/origin_test.go

@@ -259,6 +259,7 @@ func TestS3OriginConfig(t *testing.T) {
 	viper.Set("Origin.EnableVoms", false)
 	viper.Set("Origin.SelfTest", false)
 	viper.Set("Origin.Port", 0)
+	viper.Set("Server.WebPort", 0)
 	viper.Set("TLSSkipVerify", true)
 
 	mockupCancel := originMockup(ctx, egrp, t)