volume.cfg is empty (Error response from server, EOF)

[slavashvets]

Environment

• Convoy: v0.5.0
• Docker: 1.12.5-1.el7.centos (x86_64)
• OS: CentOS 7 (3.10.0-514.2.2.el7.x86_64)

Steps to reproduce

1. Download and unpack convoy
2. Install as docker plugin
3. Create loopback devices
4. Start Convoy daemon
5. Start Docker daemon
6. Start busybox containter:
   docker run -v vol1:/vol1 --volume-driver=convoy busybox touch /vol1/foo
7. Create snapshot
   convoy snapshot create vol1 --name snap1vol1
8. Create backup (using remote UNFS server)
   convoy backup create snap1vol1 --dest vfs:///apps/tmpconvoy/testnfs

Expected

All files are OK. File "convoy-objectstore/volumes/vo/l1/vol1/volume.cfg" is correct JSON.

Actual

All files are OK except convoy-objectstore/volumes/vo/l1/vol1/volume.cfg The file is empty. When I try to list backups I see the response:

convoy -d --verbose backup list vfs:///apps/tmpconvoy/testnfs/ --volume-name vol1
DEBU[0000] Sending request GET /backups/list             pkg=client
DEBU[0000] With data &{URL:vfs:///apps/tmpconvoy/testnfs/ VolumeName:vol1 SnapshotName:}  pkg=client
ERRO[0000] Error response from server, EOF

{
        "Error": "Error response from server, EOF\n"
}

Note

The bug appears only if the target folder (vfs://...) is NFS folder. It works correctly when it is just a folder in host FS.