List with no resources raises IndexError: list index out of range

[Boden R]

Using devstack all-in-one setup from master branch (neutron version 4.0.0).

Listing neutron resources that don't have any resources yet created causes an IndexError.

For example, I don't have any routers defined for my tenant:

ubuntu@l3-aa:~$ neutron router-list
list index out of range

If I run with debug to get the stack:

ubuntu@l3-aa:~$ neutron --debug router-list
...
DEBUG: keystoneauth.identity.v2 Making authentication request to http://10.34.232.114:5000/v2.0/tokens
DEBUG: keystoneauth.session REQ: curl -g -i -X GET http://10.34.232.114:9696/v2.0/routers.json -H "User-Agent: python-neutronclient" -H "Accept: application/json" -H "X-Auth-Token: {SHA1}70a319daa6da4234b31561c5d33faa4b125cfdf3"
DEBUG: keystoneauth.session RESP: [200] Date: Fri, 19 Feb 2016 15:52:53 GMT Connection: keep-alive Content-Type: application/json; charset=UTF-8 Content-Length: 15 X-Openstack-Request-Id: req-34371266-83d1-4c83-ba18-186df09cbc99
RESP BODY: {"routers": []}

ERROR: neutronclient.shell list index out of range
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/neutronclient/shell.py", line 819, in run_subcommand
    return run_command(cmd, cmd_parser, sub_argv)
  File "/usr/local/lib/python2.7/dist-packages/neutronclient/shell.py", line 105, in run_command
    return cmd.run(known_args)
  File "/usr/local/lib/python2.7/dist-packages/neutronclient/common/command.py", line 29, in run
    return super(OpenStackCommand, self).run(parsed_args)
  File "/usr/local/lib/python2.7/dist-packages/cliff/display.py", line 88, in run
    self.produce_output(parsed_args, column_names, data)
  File "/usr/local/lib/python2.7/dist-packages/cliff/lister.py", line 51, in produce_output
    parsed_args,
  File "/usr/local/lib/python2.7/dist-packages/cliff/formatters/table.py", line 64, in emit_list
    stdout, x, int(parsed_args.max_width), min_width)
  File "/usr/local/lib/python2.7/dist-packages/cliff/formatters/table.py", line 148, in _assign_max_widths
    first_line = x.get_string().splitlines()[0]
IndexError: list index out of range
list index out of range

[Hardik Italia (hardik-italia)]

Seeing same behavior in my environment too without any neutron resource.

[Ritesh Anand (ritesh-anand)]

IMO Cliff commit 94cd83f9254db3cd9eb0d58e111a2c859f2fb2b8 is causing this behavior.

[Ritesh Anand (ritesh-anand)]

Correction IMO Cliff commit 94cd83f9254db3cd9eb0d58e111a2c859f2fb2b8 fixes this behavior; we would get back to normal once we get the cliff later than that commit.
review link: https://review.openstack.org/#/c/279272/

[Akihiro Motoki (amotoki)]

This happens with cliff 1.16.0 and 1.17.0. cliff 1.15.0 works well.

[Akihiro Motoki (amotoki)]

It is a problem in cliff. A newer version of cliff needs to be released.
There is nothing to do in neutronclient.

[Akihiro Motoki (amotoki)]

it is fixed in https://review.openstack.org/#/c/279272/