for moved volumes, redirect with code 501

weed-fs/src/cmd/weed/master.go

@@ -53,7 +53,7 @@ func dirLookupHandler(w http.ResponseWriter, r *http.Request) {
 		for _, machine := range machines {
 			ret = append(ret, map[string]string{"url": machine.Url, "publicUrl": machine.PublicUrl})
 		}
-		writeJson(w, r, ret)
+		writeJson(w, r, map[string]interface{}{"locations":ret})
 	} else {
 		log.Println("Invalid volume id", volumeId)
 		writeJson(w, r, map[string]string{"error": "volume id " + volumeId.String() + " not found. " + e.Error()})

weed-fs/src/cmd/weed/volume.go

@@ -7,6 +7,7 @@ import (
 	"mime"
 	"net/http"
 	"os"
+	"pkg/operation"
 	"pkg/storage"
 	"strconv"
 	"strings"
@@ -86,6 +87,18 @@ func GetHandler(w http.ResponseWriter, r *http.Request) {
 	if *IsDebug {
 		log.Println("volume", volumeId, "reading", n)
 	}
+	if !store.HasVolume(volumeId) {
+		lookupResult, err := operation.Lookup(*server, volumeId)
+		if *IsDebug {
+			log.Println("volume", volumeId, "found on", lookupResult, "error", err)
+		}
+		if err == nil {
+			http.Redirect(w, r, "http://"+lookupResult.Locations[0].PublicUrl+r.URL.Path, http.StatusMovedPermanently)
+		} else {
+			w.WriteHeader(http.StatusNotFound)
+		}
+		return
+	}
 	cookie := n.Cookie
 	count, e := store.Read(volumeId, n)
 	if *IsDebug {

weed-fs/src/pkg/operation/lookup.go

@@ -0,0 +1,34 @@
+package operation
+
+import (
+  "encoding/json"
+  "net/url"
+  "pkg/storage"
+  "pkg/util"
+  "fmt"
+)
+
+type Location struct {
+  Url       string "url"
+  PublicUrl string "publicUrl"
+}
+type LookupResult struct {
+  Locations []Location "locations"
+  Error     string "error"
+}
+
+func Lookup(server string, vid storage.VolumeId) (*LookupResult, error) {
+  values := make(url.Values)
+  values.Add("volumeId", vid.String())
+  jsonBlob, err := util.Post("http://"+server+"/dir/lookup", values)
+  fmt.Println("Lookup Result:", string(jsonBlob))
+  if err != nil {
+    return nil, err
+  }
+  var ret LookupResult
+  err = json.Unmarshal(jsonBlob, &ret)
+  if err != nil {
+    return nil, err
+  }
+  return &ret, nil
+}

weed-fs/src/pkg/storage/store.go

@@ -136,6 +136,11 @@ func (s *Store) Read(i VolumeId, n *Needle) (int, error) {
 	return 0, errors.New("Not Found")
 }
 
+func (s *Store) HasVolume(i VolumeId) bool {
+  _, ok := s.volumes[i]
+  return ok
+}
+
 type VolumeLocations struct {
 	Vid       VolumeId
 	Locations []string