Error when running script

[Albert T]

I'm trying to setup your script in a Ubuntu 15 instance but I'm getting the following error when I run

python3 varnishbackup.py --volume-ids=vol-0a7de8c7c8b38fe5a --expiry-days=3

Creating snapshots...

('Connection aborted.', gaierror(-2, 'Name or service not known'))
Traceback (most recent call last):
File "varnishbackup.py", line 120, in
snapshots = createSnapshots(volumeIds)
File "varnishbackup.py", line 41, in createSnapshots
snapshots.append(createSnapshotForVolume(volumeId))
File "varnishbackup.py", line 78, in createSnapshotForVolume
"--profile", profile
File "/usr/lib/python3.4/json/init.py", line 318, in loads
return _default_decoder.decode(s)
File "/usr/lib/python3.4/json/decoder.py", line 343, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python3.4/json/decoder.py", line 361, in raw_decode
raise ValueError(errmsg("Expecting value", s, err.value)) from None
ValueError: Expecting value: line 1 column 1 (char 0)