volume: add -id flag for stable volume server identity

Add -id command line flag to volume server that allows specifying a stable
identifier independent of the IP address. This is useful for Kubernetes
deployments with hostPath volumes where pods can be rescheduled to different
nodes while the persisted data remains on the original node.

Usage: weed volume -id=node-1 -ip=10.0.0.1 ...

If -id is not specified, it defaults to ip:port for backward compatibility.

Fixes https://github.com/seaweedfs/seaweedfs/issues/7487

weed/command/volume.go

@@ -41,6 +41,7 @@ type VolumeServerOptions struct {
 	folderMaxLimits           []int32
 	idxFolder                 *string
 	ip                        *string
+	id                        *string
 	publicUrl                 *string
 	bindIp                    *string
 	mastersString             *string
@@ -78,6 +79,7 @@ func init() {
 	v.portGrpc = cmdVolume.Flag.Int("port.grpc", 0, "grpc listen port")
 	v.publicPort = cmdVolume.Flag.Int("port.public", 0, "port opened to public")
 	v.ip = cmdVolume.Flag.String("ip", util.DetectedHostAddress(), "ip or server name, also used as identifier")
+	v.id = cmdVolume.Flag.String("id", "", "volume server id. If empty, default to ip:port")
 	v.publicUrl = cmdVolume.Flag.String("publicUrl", "", "Publicly accessible address")
 	v.bindIp = cmdVolume.Flag.String("ip.bind", "", "ip address to bind to. If empty, default to same as -ip option.")
 	v.mastersString = cmdVolume.Flag.String("master", "localhost:9333", "comma-separated master servers")
@@ -253,8 +255,14 @@ func (v VolumeServerOptions) startVolumeServer(volumeFolders, maxVolumeCounts, v
 		volumeNeedleMapKind = storage.NeedleMapLevelDbLarge
 	}
 
+	// Determine volume server ID: if not specified, use ip:port
+	volumeServerId := *v.id
+	if volumeServerId == "" {
+		volumeServerId = util.JoinHostPort(*v.ip, *v.port)
+	}
+
 	volumeServer := weed_server.NewVolumeServer(volumeMux, publicVolumeMux,
-		*v.ip, *v.port, *v.portGrpc, *v.publicUrl,
+		*v.ip, *v.port, *v.portGrpc, *v.publicUrl, volumeServerId,
 		v.folders, v.folderMaxLimits, minFreeSpaces, diskTypes,
 		*v.idxFolder,
 		volumeNeedleMapKind,

weed/server/master_grpc_server.go

@@ -137,8 +137,8 @@ func (ms *MasterServer) SendHeartbeat(stream master_pb.Seaweed_SendHeartbeatServ
 			dcName, rackName := ms.Topo.Configuration.Locate(heartbeat.Ip, heartbeat.DataCenter, heartbeat.Rack)
 			dc := ms.Topo.GetOrCreateDataCenter(dcName)
 			rack := dc.GetOrCreateRack(rackName)
-			dn = rack.GetOrCreateDataNode(heartbeat.Ip, int(heartbeat.Port), int(heartbeat.GrpcPort), heartbeat.PublicUrl, heartbeat.MaxVolumeCounts)
-			glog.V(0).Infof("added volume server %d: %v:%d %v", dn.Counter, heartbeat.GetIp(), heartbeat.GetPort(), heartbeat.LocationUuids)
+			dn = rack.GetOrCreateDataNode(heartbeat.Ip, int(heartbeat.Port), int(heartbeat.GrpcPort), heartbeat.PublicUrl, heartbeat.Id, heartbeat.MaxVolumeCounts)
+			glog.V(0).Infof("added volume server %d: %v (id=%s, ip=%v:%d) %v", dn.Counter, dn.Id(), heartbeat.Id, heartbeat.GetIp(), heartbeat.GetPort(), heartbeat.LocationUuids)
 			uuidlist, err := ms.RegisterUuids(heartbeat)
 			if err != nil {
 				if stream_err := stream.Send(&master_pb.HeartbeatResponse{

weed/server/volume_server.go

@@ -55,7 +55,7 @@ type VolumeServer struct {
 }
 
 func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
-	port int, grpcPort int, publicUrl string,
+	port int, grpcPort int, publicUrl string, id string,
 	folders []string, maxCounts []int32, minFreeSpaces []util.MinFreeSpace, diskTypes []types.DiskType,
 	idxFolder string,
 	needleMapKind storage.NeedleMapKind,
@@ -114,7 +114,7 @@ func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
 
 	vs.checkWithMaster()
 
-	vs.store = storage.NewStore(vs.grpcDialOption, ip, port, grpcPort, publicUrl, folders, maxCounts, minFreeSpaces, idxFolder, vs.needleMapKind, diskTypes, ldbTimeout)
+	vs.store = storage.NewStore(vs.grpcDialOption, ip, port, grpcPort, publicUrl, id, folders, maxCounts, minFreeSpaces, idxFolder, vs.needleMapKind, diskTypes, ldbTimeout)
 	vs.guard = security.NewGuard(whiteList, signingKey, expiresAfterSec, readSigningKey, readExpiresAfterSec)
 
 	handleStaticResources(adminMux)