add proxy mode to read non-local volumes

weed/server/volume_server.go

@@ -28,7 +28,7 @@ type VolumeServer struct {
 
 	needleMapKind           storage.NeedleMapKind
 	FixJpgOrientation       bool
-	ReadRedirect            bool
+	ReadMode            	string
 	compactionBytePerSecond int64
 	metricsAddress          string
 	metricsIntervalSec      int
@@ -50,7 +50,7 @@ func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
 	dataCenter string, rack string,
 	whiteList []string,
 	fixJpgOrientation bool,
-	readRedirect bool,
+	readMode string,
 	compactionMBPerSecond int,
 	fileSizeLimitMB int,
 	concurrentUploadLimit int64,
@@ -72,7 +72,7 @@ func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
 		rack:                    rack,
 		needleMapKind:           needleMapKind,
 		FixJpgOrientation:       fixJpgOrientation,
-		ReadRedirect:            readRedirect,
+		ReadMode:				 readMode,
 		grpcDialOption:          security.LoadClientTLS(util.GetViper(), "grpc.volume"),
 		compactionBytePerSecond: int64(compactionMBPerSecond) * 1024 * 1024,
 		fileSizeLimitBytes:      int64(fileSizeLimitMB) * 1024 * 1024,

weed/server/volume_server_handlers.go

@@ -1,6 +1,7 @@
 package weed_server
 
 import (
+	"fmt"
 	"net/http"
 	"strconv"
 	"strings"
@@ -81,6 +82,7 @@ func getContentLength(r *http.Request) int64 {
 }
 
 func (vs *VolumeServer) publicReadOnlyHandler(w http.ResponseWriter, r *http.Request) {
+	fmt.Printf("publicReadOnlyHandler in.")
 	w.Header().Set("Server", "SeaweedFS Volume "+util.VERSION)
 	if r.Header.Get("Origin") != "" {
 		w.Header().Set("Access-Control-Allow-Origin", "*")

weed/server/volume_server_handlers_read.go

@@ -58,14 +58,53 @@ func (vs *VolumeServer) GetOrHeadHandler(w http.ResponseWriter, r *http.Request)
 	hasVolume := vs.store.HasVolume(volumeId)
 	_, hasEcVolume := vs.store.FindEcVolume(volumeId)
 	if !hasVolume && !hasEcVolume {
-		if !vs.ReadRedirect {
-			glog.V(2).Infoln("volume is not local:", err, r.URL.Path)
+		if vs.ReadMode == "local" {
+			glog.V(0).Infoln("volume is not local:", err, r.URL.Path)
 			w.WriteHeader(http.StatusNotFound)
 			return
 		}
 		lookupResult, err := operation.Lookup(vs.GetMaster, volumeId.String())
 		glog.V(2).Infoln("volume", volumeId, "found on", lookupResult, "error", err)
-		if err == nil && len(lookupResult.Locations) > 0 {
+		if err != nil || len(lookupResult.Locations) <= 0{
+			glog.V(0).Infoln("lookup error:", err, r.URL.Path)
+			w.WriteHeader(http.StatusNotFound)
+			return
+		}
+		if vs.ReadMode == "remote" {
+			// proxy client request to target server
+			u, _ := url.Parse(util.NormalizeUrl(lookupResult.Locations[0].Url))
+			r.URL.Host = u.Host
+			r.URL.Scheme = u.Scheme
+			request, err := http.NewRequest("GET", r.URL.String(), nil)
+			if err != nil {
+				glog.V(0).Infof("failed to instance http request of url %s: %v", r.URL.String(), err)
+				w.WriteHeader(http.StatusInternalServerError)
+				return
+			}
+			for k, vv := range r.Header {
+				for _, v := range vv {
+					request.Header.Add(k, v)
+				}
+			}
+
+			response, err := client.Do(request)
+			if err != nil {
+				glog.V(0).Infof("request remote url %s: %v", r.URL.String(), err)
+				w.WriteHeader(http.StatusInternalServerError)
+				return
+			}
+			defer util.CloseResponse(response)
+			// proxy target response to client
+			for k, vv := range response.Header {
+				for _, v := range vv {
+					w.Header().Add(k, v)
+				}
+			}
+			w.WriteHeader(response.StatusCode)
+			io.Copy(w, response.Body)
+			return
+		} else {
+			// redirect
 			u, _ := url.Parse(util.NormalizeUrl(lookupResult.Locations[0].PublicUrl))
 			u.Path = fmt.Sprintf("%s/%s,%s", u.Path, vid, fid)
 			arg := url.Values{}
@@ -74,12 +113,8 @@ func (vs *VolumeServer) GetOrHeadHandler(w http.ResponseWriter, r *http.Request)
 			}
 			u.RawQuery = arg.Encode()
 			http.Redirect(w, r, u.String(), http.StatusMovedPermanently)
-
-		} else {
-			glog.V(2).Infoln("lookup error:", err, r.URL.Path)
-			w.WriteHeader(http.StatusNotFound)
+			return
 		}
-		return
 	}
 	cookie := n.Cookie