[Sahara] Copy node group template button doesn't work in some cases

[Andrew Lazarev]

Copy node group template doesn't work if node group template contains None as "security_groups" field. Note, it is impossible to get into such state using horizon.

Steps to reproduce:
1. Create node group template with security_groups=None (default value) using REST API. Note, horizon puts [] for this field.
2. Open node group templates list in horizon
3. Click 'Copy Template' button

Observed behavior: 'Danger: An error occurred. Please try again later.' error

Stacktrace from horizon:
Internal Server Error: /project/data_processing/nodegroup_templates/1e560118-3281-49a3-abc7-9742a3fe8408/copy
Traceback (most recent call last):
  File "/Users/alazarev/openstack/horizon/.venv/lib/python2.7/site-packages/django/core/handlers/base.py", line 112, in get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/Users/alazarev/openstack/horizon/horizon/decorators.py", line 36, in dec
    return view_func(request, *args, **kwargs)
  File "/Users/alazarev/openstack/horizon/horizon/decorators.py", line 52, in dec
    return view_func(request, *args, **kwargs)
  File "/Users/alazarev/openstack/horizon/horizon/decorators.py", line 36, in dec
    return view_func(request, *args, **kwargs)
  File "/Users/alazarev/openstack/horizon/horizon/decorators.py", line 84, in dec
    return view_func(request, *args, **kwargs)
  File "/Users/alazarev/openstack/horizon/.venv/lib/python2.7/site-packages/django/views/generic/base.py", line 69, in view
    return self.dispatch(request, *args, **kwargs)
  File "/Users/alazarev/openstack/horizon/.venv/lib/python2.7/site-packages/django/views/generic/base.py", line 87, in dispatch
    return handler(request, *args, **kwargs)
  File "/Users/alazarev/openstack/horizon/horizon/workflows/views.py", line 144, in get
    context = self.get_context_data(**kwargs)
  File "/Users/alazarev/openstack/horizon/openstack_dashboard/dashboards/project/data_processing/nodegroup_templates/views.py", line 89, in get_context_data
    .get_context_data(**kwargs)
  File "/Users/alazarev/openstack/horizon/horizon/workflows/views.py", line 91, in get_context_data
    workflow = self.get_workflow()
  File "/Users/alazarev/openstack/horizon/horizon/workflows/views.py", line 81, in get_workflow
    entry_point=entry_point)
  File "/Users/alazarev/openstack/horizon/openstack_dashboard/dashboards/project/data_processing/nodegroup_templates/workflows/copy.py", line 71, in __init__
    [(sg, sg) for sg in template.security_groups])
TypeError: 'NoneType' object is not iterable

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/153105

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/153105
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=4da82b5acf7639e2b5e33739fa5de50ce55cfcb5
Submitter: Jenkins
Branch: master

commit 4da82b5acf7639e2b5e33739fa5de50ce55cfcb5
Author: Andrew Lazarev <email address hidden>
Date: Wed Feb 4 17:44:24 2015 -0800

    [Sahara] Fixed copy nodegroup template when sec groups missing

    'security_groups' is not required field. So, we should handle
    None value.

    Change-Id: I0233a0e247912f3f8f34f1c85e833eee4b1aa8f8
    Closes-Bug: #1418278