dhcpcheck discover fails when there is no interface specified

[Sebastian Kalinowski]

When running 'dhcpcheck discover' (without --iface param) there is an error:

[root@fuel network_checker]# dhcpcheck discover --debug
'NoneType' object is not iterable
Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/cliff/app.py", line 282, in run_subcommand
    result = cmd.run(parsed_args)
  File "/usr/lib/python2.6/site-packages/cliff/display.py", line 80, in run
    column_names, data = self.take_action(parsed_args)
  File "/usr/lib/python2.6/site-packages/nailgun_net_check-0.2-py2.6.egg/dhcp_checker/commands.py", line 55, in take_action
    repeat=parsed_args.repeat))
  File "/usr/lib/python2.6/site-packages/nailgun_net_check-0.2-py2.6.egg/dhcp_checker/api.py", line 77, in check_dhcp
    for iface in ifaces:
TypeError: 'NoneType' object is not iterable
2014-11-25 10:45:44 ERROR (app) 'NoneType' object is not iterable

'--iface' param is optional and it's helps message tells that "If no eth provided - will run against all except lo" which is not true [1].

There are two options:
1) make '--iface' as a required param and change it's help message
2) run discover for all interfaces except lo as help message tells

Checked on fuel-web revision 603a8d4.

[1] https://github.com/stackforge/fuel-web/blob/master/network_checker/dhcp_checker/commands.py#L44-L46

[Vladimir Sharshov (vsharshov)]

We have workaround. Can be safely moved to 8.0

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/248826

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/248826
Committed: https://git.openstack.org/cgit/openstack/network-checker/commit/?id=bf78100d2d1b831f6a44c1c05c6727d7805ff296
Submitter: Jenkins
Branch: master

commit bf78100d2d1b831f6a44c1c05c6727d7805ff296
Author: Ruslan Aliev <email address hidden>
Date: Mon Nov 23 20:01:15 2015 +0300

    Fixes dhcp checking with no interface provided

    When running 'dhcpcheck discover' without --iface param,
    there is an error 'NoneType object is not iterable'. This
    patch fixes that error according '--ifaces' help message
    and if '--ifaces' option not specified, dhcp check runs
    discover for all interfaces except lo.

    Change-Id: Iec4b01792d36a91ec9afca415bcc2fc602be1e00
    Closes-Bug: #1396085
    Signed-off-by: Ruslan Aliev <email address hidden>