tier: support remote file attributes and remember the file extension

weed/storage/backend/backend.go

@@ -24,7 +24,7 @@ type BackendStorageFile interface {
 type BackendStorage interface {
 	ToProperties() map[string]string
 	NewStorageFile(key string, tierInfo *volume_server_pb.VolumeTierInfo) BackendStorageFile
-	CopyFile(f *os.File, fn func(progressed int64, percentage float32) error) (key string, size int64, err error)
+	CopyFile(f *os.File, attributes map[string]string, fn func(progressed int64, percentage float32) error) (key string, size int64, err error)
 	DownloadFile(fileName string, key string, fn func(progressed int64, percentage float32) error) (size int64, err error)
 	DeleteFile(key string) (err error)
 }

weed/storage/backend/s3_backend/s3_backend.go

@@ -75,13 +75,13 @@ func (s *S3BackendStorage) NewStorageFile(key string, tierInfo *volume_server_pb
 	return f
 }
 
-func (s *S3BackendStorage) CopyFile(f *os.File, fn func(progressed int64, percentage float32) error) (key string, size int64, err error) {
+func (s *S3BackendStorage) CopyFile(f *os.File, attributes map[string]string, fn func(progressed int64, percentage float32) error) (key string, size int64, err error) {
 	randomUuid, _ := uuid.NewRandom()
 	key = randomUuid.String()
 
 	glog.V(1).Infof("copying dat file of %s to remote s3.%s as %s", f.Name(), s.id, key)
 
-	size, err = uploadToS3(s.conn, f.Name(), s.bucket, key, fn)
+	size, err = uploadToS3(s.conn, f.Name(), s.bucket, key, attributes, fn)
 
 	return
 }

weed/storage/backend/s3_backend/s3_upload.go

@@ -8,10 +8,12 @@ import (
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/service/s3/s3iface"
 	"github.com/aws/aws-sdk-go/service/s3/s3manager"
+
 	"github.com/chrislusf/seaweedfs/weed/glog"
 )
 
 func uploadToS3(sess s3iface.S3API, filename string, destBucket string, destKey string,
+	attributes map[string]string,
 	fn func(progressed int64, percentage float32) error) (fileSize int64, err error) {
 
 	//open the file
@@ -46,6 +48,15 @@ func uploadToS3(sess s3iface.S3API, filename string, destBucket string, destKey
 		fn:   fn,
 	}
 
+	// process tagging
+	tags := ""
+	for k, v := range attributes {
+		if len(tags) > 0 {
+			tags = tags + "&"
+		}
+		tags = tags + k + "=" + v
+	}
+
 	// Upload the file to S3.
 	var result *s3manager.UploadOutput
 	result, err = uploader.Upload(&s3manager.UploadInput{
@@ -55,6 +66,7 @@ func uploadToS3(sess s3iface.S3API, filename string, destBucket string, destKey
 		ACL:                  aws.String("private"),
 		ServerSideEncryption: aws.String("AES256"),
 		StorageClass:         aws.String("STANDARD_IA"),
+		Tagging:              aws.String(tags),
 	})
 
 	//in case it fails to upload