vm/gce: accept un-tar-ed image

vm/gce differs from other VM types in that it accepts image
in a weird, GCE-specific format (namely, image named disk.raw
is put into .tar.gz file). This makes it impossible to write
generic code that creates images for any VM types.

Make vm/gce accept just image like e.g. vm/qemu
and handle own specifics internally.

1 files changed, 16 insertions, 6 deletions

diff --git a/pkg/gcs/gcs.go b/pkg/gcs/gcs.go
index 0121d2aeb..97883256a 100644
--- a/pkg/gcs/gcs.go
+++ b/pkg/gcs/gcs.go
@@ -80,25 +80,35 @@ func (client *Client) Read(gcsFile string) (*File, error) {
 }
 
 func (client *Client) UploadFile(localFile, gcsFile string) error {
-	bucket, filename, err := split(gcsFile)
+	local, err := os.Open(localFile)
 	if err != nil {
 		return err
 	}
-	local, err := os.Open(localFile)
+	defer local.Close()
+
+	w, err := client.FileWriter(gcsFile)
 	if err != nil {
 		return err
 	}
-	defer local.Close()
-	bkt := client.client.Bucket(bucket)
-	f := bkt.Object(filename)
-	w := f.NewWriter(client.ctx)
 	defer w.Close()
+
 	if _, err := io.Copy(w, local); err != nil {
 		return err
 	}
 	return nil
 }
 
+func (client *Client) FileWriter(gcsFile string) (io.WriteCloser, error) {
+	bucket, filename, err := split(gcsFile)
+	if err != nil {
+		return nil, err
+	}
+	bkt := client.client.Bucket(bucket)
+	f := bkt.Object(filename)
+	w := f.NewWriter(client.ctx)
+	return w, nil
+}
+
 func split(file string) (bucket, filename string, err error) {
 	pos := strings.IndexByte(file, '/')
 	if pos == -1 {