read <- remote_storage

weed/filer/filer_remote_storage.go

@@ -45,7 +45,10 @@ func (rs *FilerRemoteStorage) LoadRemoteStorageConfigurationsAndMapping(filer *F
 
 	for _, entry := range entries {
 		if entry.Name() == REMOTE_STORAGE_MOUNT_FILE {
-			rs.loadRemoteStorageMountMapping(entry.Content)
+			if err := rs.loadRemoteStorageMountMapping(entry.Content); err != nil {
+				return err
+			}
+			continue
 		}
 		if !strings.HasSuffix(entry.Name(), REMOTE_STORAGE_CONF_SUFFIX) {
 			return nil
@@ -75,16 +78,11 @@ func (rs *FilerRemoteStorage) mapDirectoryToRemoteStorage(dir util.FullPath, loc
 }
 
 func (rs *FilerRemoteStorage) FindMountDirectory(p util.FullPath) (mountDir util.FullPath, remoteLocation *filer_pb.RemoteStorageLocation) {
-	var storageLocation string
 	rs.rules.MatchPrefix([]byte(p), func(key []byte, value interface{}) bool {
-		mountDir = util.FullPath(string(key))
-		storageLocation = value.(string)
+		mountDir = util.FullPath(string(key[:len(key)-1]))
+		remoteLocation = value.(*filer_pb.RemoteStorageLocation)
 		return true
 	})
-	if storageLocation == "" {
-		return
-	}
-	remoteLocation = remote_storage.ParseLocation(storageLocation)
 	return
 }
 
@@ -118,8 +116,8 @@ func (rs *FilerRemoteStorage) GetRemoteStorageClient(storageName string) (client
 	return
 }
 
-func AddMapping(oldContent []byte, dir string, storageLocation *filer_pb.RemoteStorageLocation) (newContent []byte, err error) {
-	mappings := &filer_pb.RemoteStorageMapping{
+func UnmarshalRemoteStorageMappings(oldContent []byte) (mappings *filer_pb.RemoteStorageMapping, err error) {
+	mappings = &filer_pb.RemoteStorageMapping{
 		Mappings: make(map[string]*filer_pb.RemoteStorageLocation),
 	}
 	if len(oldContent) > 0 {
@@ -127,6 +125,14 @@ func AddMapping(oldContent []byte, dir string, storageLocation *filer_pb.RemoteS
 			glog.Warningf("unmarshal existing mappings: %v", err)
 		}
 	}
+	return
+}
+
+func AddRemoteStorageMapping(oldContent []byte, dir string, storageLocation *filer_pb.RemoteStorageLocation) (newContent []byte, err error) {
+	mappings, unmarshalErr := UnmarshalRemoteStorageMappings(oldContent)
+	if unmarshalErr != nil {
+		// skip
+	}
 
 	// set the new mapping
 	mappings.Mappings[dir] = storageLocation

weed/filer/read_remote.go

@@ -3,17 +3,16 @@ package filer
 import (
 	"fmt"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
-	"io"
 )
 
 func (entry *Entry) IsRemoteOnly() bool {
 	return len(entry.Chunks) == 0 && entry.Remote != nil && entry.Remote.Size > 0
 }
 
-func (f *Filer) ReadRemote(w io.Writer, entry *Entry, offset int64, size int64) error {
+func (f *Filer) ReadRemote(entry *Entry, offset int64, size int64) (data[]byte, err error) {
 	client, _, found := f.RemoteStorage.GetRemoteStorageClient(entry.Remote.StorageName)
 	if !found {
-		return fmt.Errorf("remote storage %v not found", entry.Remote.StorageName)
+		return nil, fmt.Errorf("remote storage %v not found", entry.Remote.StorageName)
 	}
 
 	mountDir, remoteLoation := f.RemoteStorage.FindMountDirectory(entry.FullPath)
@@ -26,8 +25,5 @@ func (f *Filer) ReadRemote(w io.Writer, entry *Entry, offset int64, size int64)
 		Path:   remoteFullPath,
 	}
 
-	client.ReadFile(sourceLoc, offset, size, func(w io.Writer) error {
-		return nil
-	})
-	return nil
+	return client.ReadFile(sourceLoc, offset, size)
 }

weed/pb/filer_pb/filer_pb_helper.go

@@ -147,3 +147,7 @@ func (fp *FilerConf_PathConf) Key() interface{} {
 	key, _ := proto.Marshal(fp)
 	return string(key)
 }
+func (fp *RemoteStorageLocation) Key() interface{} {
+	key, _ := proto.Marshal(fp)
+	return string(key)
+}

weed/pb/volume_server.proto

@@ -56,6 +56,8 @@ service VolumeServer {
     }
     rpc WriteNeedleBlob (WriteNeedleBlobRequest) returns (WriteNeedleBlobResponse) {
     }
+    rpc FetchAndWriteNeedle (FetchAndWriteNeedleRequest) returns (FetchAndWriteNeedleResponse) {
+    }
 
     rpc VolumeTailSender (VolumeTailSenderRequest) returns (stream VolumeTailSenderResponse) {
     }
@@ -276,6 +278,23 @@ message WriteNeedleBlobRequest {
 }
 message WriteNeedleBlobResponse {
 }
+message FetchAndWriteNeedleRequest {
+    uint32 volume_id = 1;
+    uint64 needle_id = 2;
+    int64 offset = 3;
+    int64 size = 4;
+    // remote info
+    string remote_type = 5;
+    string remote_name = 6;
+    string s3_access_key = 8;
+    string s3_secret_key = 9;
+    string s3_region = 10;
+    string s3_endpoint = 11;
+    string remote_bucket = 12;
+    string remote_key = 13;
+}
+message FetchAndWriteNeedleResponse {
+}
 
 message VolumeTailSenderRequest {
     uint32 volume_id = 1;

weed/remote_storage/remote_storage.go

@@ -3,7 +3,6 @@ package remote_storage
 import (
 	"fmt"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
-	"io"
 	"strings"
 	"sync"
 )
@@ -31,7 +30,7 @@ type VisitFunc func(dir string, name string, isDirectory bool, remoteEntry *file
 
 type RemoteStorageClient interface {
 	Traverse(loc *filer_pb.RemoteStorageLocation, visitFn VisitFunc) error
-	ReadFile(loc *filer_pb.RemoteStorageLocation, offset int64, size int64, writeFn func(w io.Writer) error) error
+	ReadFile(loc *filer_pb.RemoteStorageLocation, offset int64, size int64) (data[]byte, err error)
 }
 
 type RemoteStorageClientMaker interface {

weed/remote_storage/s3/s3_storage_client.go

@@ -7,10 +7,10 @@ import (
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/s3"
 	"github.com/aws/aws-sdk-go/service/s3/s3iface"
+	"github.com/aws/aws-sdk-go/service/s3/s3manager"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 	"github.com/chrislusf/seaweedfs/weed/remote_storage"
 	"github.com/chrislusf/seaweedfs/weed/util"
-	"io"
 )
 
 func init() {
@@ -65,7 +65,7 @@ func (s s3RemoteStorageClient) Traverse(remote *filer_pb.RemoteStorageLocation,
 	for !isLastPage && err == nil {
 		listErr := s.conn.ListObjectsV2Pages(listInput, func(page *s3.ListObjectsV2Output, lastPage bool) bool {
 			for _, content := range page.Contents {
-				key := (*content.Key)
+				key := *content.Key
 				if len(pathKey) == 0 {
 					key = "/" + key
 				} else {
@@ -91,6 +91,23 @@ func (s s3RemoteStorageClient) Traverse(remote *filer_pb.RemoteStorageLocation,
 	}
 	return
 }
-func (s s3RemoteStorageClient) ReadFile(loc *filer_pb.RemoteStorageLocation, offset int64, size int64, writeFn func(w io.Writer) error) error {
-	return nil
+func (s s3RemoteStorageClient) ReadFile(loc *filer_pb.RemoteStorageLocation, offset int64, size int64) (data[]byte, err error) {
+	downloader := s3manager.NewDownloaderWithClient(s.conn, func(u *s3manager.Downloader) {
+		u.PartSize = int64(4 * 1024 * 1024)
+		u.Concurrency = 1
+	})
+	
+	dataSlice := make([]byte, int(size))
+	writerAt := aws.NewWriteAtBuffer(dataSlice)
+
+	_, err = downloader.Download(writerAt, &s3.GetObjectInput{
+		Bucket:                     aws.String(loc.Bucket),
+		Key:                        aws.String(loc.Path[1:]),
+		Range:                      aws.String(fmt.Sprintf("bytes=%d-%d", offset, offset+size-1)),
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed to download file %s%s: %v", loc.Bucket, loc.Path, err)
+	}
+
+	return writerAt.Bytes(), nil
 }

weed/server/filer_server_handlers_read.go

@@ -164,10 +164,12 @@ func (fs *FilerServer) GetOrHeadHandler(w http.ResponseWriter, r *http.Request)
 			return err
 		}
 		if entry.IsRemoteOnly() {
-			err = fs.filer.ReadRemote(writer, entry, offset, size)
+			var data []byte
+			data, err = fs.filer.ReadRemote(entry, offset, size)
 			if err != nil {
 				glog.Errorf("failed to read remote %s: %v", r.URL, err)
 			}
+			_, err = w.Write(data)
 		} else {
 			err = filer.StreamContent(fs.filer.MasterClient, writer, entry.Chunks, offset, size)
 			if err != nil {

weed/server/volume_grpc_read_write.go

@@ -3,7 +3,9 @@ package weed_server
 import (
 	"context"
 	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 	"github.com/chrislusf/seaweedfs/weed/pb/volume_server_pb"
+	"github.com/chrislusf/seaweedfs/weed/remote_storage"
 	"github.com/chrislusf/seaweedfs/weed/storage/needle"
 	"github.com/chrislusf/seaweedfs/weed/storage/types"
 )
@@ -36,3 +38,41 @@ func (vs *VolumeServer) WriteNeedleBlob(ctx context.Context, req *volume_server_
 
 	return resp, nil
 }
+
+func (vs *VolumeServer) FetchAndWriteNeedle(ctx context.Context, req *volume_server_pb.FetchAndWriteNeedleRequest) (resp *volume_server_pb.FetchAndWriteNeedleResponse, err error) {
+	resp = &volume_server_pb.FetchAndWriteNeedleResponse{}
+	v := vs.store.GetVolume(needle.VolumeId(req.VolumeId))
+	if v == nil {
+		return nil, fmt.Errorf("not found volume id %d", req.VolumeId)
+	}
+
+	remoteConf := &filer_pb.RemoteConf{
+		Type: req.RemoteType,
+		Name: req.RemoteName,
+		S3AccessKey: req.S3AccessKey,
+		S3SecretKey: req.S3SecretKey,
+		S3Region: req.S3Region,
+		S3Endpoint: req.S3Endpoint,
+	}
+
+	client, getClientErr := remote_storage.GetRemoteStorage(remoteConf)
+	if getClientErr != nil  {
+		return nil, fmt.Errorf("get remote client: %v", getClientErr)
+	}
+
+	remoteStorageLocation := &filer_pb.RemoteStorageLocation{
+		Name:   req.RemoteName,
+		Bucket: req.RemoteBucket,
+		Path:   req.RemoteKey,
+	}
+	data, ReadRemoteErr := client.ReadFile(remoteStorageLocation, req.Offset, req.Size)
+	if ReadRemoteErr != nil {
+		return nil, fmt.Errorf("read from remote %+v: %v", remoteStorageLocation, ReadRemoteErr)
+	}
+
+	if err = v.WriteNeedleBlob(types.NeedleId(req.NeedleId), data, types.Size(req.Size)); err != nil {
+		return nil, fmt.Errorf("write blob needle %d size %d: %v", req.NeedleId, req.Size, err)
+	}
+
+	return resp, nil
+}

weed/shell/command_remote_mount.go

@@ -8,6 +8,7 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 	"github.com/chrislusf/seaweedfs/weed/remote_storage"
 	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/golang/protobuf/jsonpb"
 	"github.com/golang/protobuf/proto"
 	"io"
 )
@@ -49,6 +50,10 @@ func (c *commandRemoteMount) Do(args []string, commandEnv *CommandEnv, writer io
 		return nil
 	}
 
+	if *dir == "" {
+		return c.listExistingRemoteStorageMounts(commandEnv, writer)
+	}
+
 	remoteStorageLocation := remote_storage.ParseLocation(*remote)
 
 	// find configuration for remote storage
@@ -71,6 +76,34 @@ func (c *commandRemoteMount) Do(args []string, commandEnv *CommandEnv, writer io
 	return nil
 }
 
+func (c *commandRemoteMount) listExistingRemoteStorageMounts(commandEnv *CommandEnv, writer io.Writer) (err error) {
+
+	// read current mapping
+	var oldContent []byte
+	err = commandEnv.WithFilerClient(func(client filer_pb.SeaweedFilerClient) error {
+		oldContent, err = filer.ReadInsideFiler(client, filer.DirectoryEtcRemote, filer.REMOTE_STORAGE_MOUNT_FILE)
+		return err
+	})
+	if err != nil {
+		if err != filer_pb.ErrNotFound {
+			return fmt.Errorf("read existing mapping: %v", err)
+		}
+	}
+
+	mappings, unmarshalErr := filer.UnmarshalRemoteStorageMappings(oldContent)
+	if unmarshalErr != nil {
+		return unmarshalErr
+	}
+
+	m := jsonpb.Marshaler{
+		EmitDefaults: false,
+		Indent:       "  ",
+	}
+
+	return m.Marshal(writer, mappings)
+
+}
+
 func (c *commandRemoteMount) findRemoteStorageConfiguration(commandEnv *CommandEnv, writer io.Writer, remote *filer_pb.RemoteStorageLocation) (conf *filer_pb.RemoteConf, err error) {
 
 	// read storage configuration data
@@ -178,7 +211,7 @@ func (c *commandRemoteMount) pullMetadata(commandEnv *CommandEnv, writer io.Writ
 					existingEntry.Attributes.Mtime = remoteEntry.LastModifiedAt
 					_, updateErr := client.UpdateEntry(ctx, &filer_pb.UpdateEntryRequest{
 						Directory: localDir,
-						Entry: existingEntry,
+						Entry:     existingEntry,
 					})
 					return updateErr
 				}
@@ -210,7 +243,7 @@ func (c *commandRemoteMount) saveMountMapping(commandEnv *CommandEnv, writer io.
 	}
 
 	// add new mapping
-	newContent, err = filer.AddMapping(oldContent, dir, remoteStorageLocation)
+	newContent, err = filer.AddRemoteStorageMapping(oldContent, dir, remoteStorageLocation)
 	if err != nil {
 		return fmt.Errorf("add mapping %s~%s: %v", dir, remoteStorageLocation, err)
 	}