Following the documentation at: https://wikitech.wikimedia.org/wiki/Help:Adding_Disk_Space_to_Cloud_VPS_instances#Cinder:_Attachable_Block_Storage_for_cloud-vps
will result in an error when you attempt to run sudo prepare_cinder_volume.
Steps to reproduce:
- Create a volume in Horizon
- Attach the volume to an VM in the desired project
- Run on the VM sudo prepare_cinder_volume
Error Log:
root@puppet-lta:~# sudo prepare_cinder_volume
Traceback (most recent call last):
File "/usr/sbin/prepare_cinder_volume", line 157, in <module>
devdict = block_dev_dict()
File "/usr/sbin/prepare_cinder_volume", line 15, in block_dev_dict
blockdict = json.loads(jsonblocks)
File "/usr/lib/python3.5/json/__init__.py", line 319, in loads
return _default_decoder.decode(s)
File "/usr/lib/python3.5/json/decoder.py", line 339, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python3.5/json/decoder.py", line 357, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)