Command dos.py slave-add doesn't work

[Dmitry Dmitriev]

Detailed bug description:

Command dos.py slave-add crashes with the following error message:

(fuel-devops-venv)engineer@cz5450:~ $ dos.py slave-add dd-env
Traceback (most recent call last):
  File "/home/engineer/fuel-devops-venv/bin/dos.py", line 22, in <module>
    main()
  File "/home/engineer/fuel-devops-venv/local/lib/python2.7/site-packages/devops/shell.py", line 602, in main
    Shell(args).execute()
  File "/home/engineer/fuel-devops-venv/local/lib/python2.7/site-packages/devops/shell.py", line 52, in execute
    self.commands.get(self.params.command)(self)
  File "/home/engineer/fuel-devops-venv/local/lib/python2.7/site-packages/devops/shell.py", line 232, in do_slave_add
    group = self.env.get_group(name='default')
  File "/home/engineer/fuel-devops-venv/local/lib/python2.7/site-packages/devops/models/environment.py", line 66, in get_group
    return self.group_set.get(**kwargs)
  File "/home/engineer/fuel-devops-venv/local/lib/python2.7/site-packages/django/db/models/manager.py", line 127, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/home/engineer/fuel-devops-venv/local/lib/python2.7/site-packages/django/db/models/query.py", line 334, in get
    self.model._meta.object_name
devops.models.group.DoesNotExist: Group matching query does not exist.
(fuel-devops-venv)engineer@cz5450:~ $

Steps to reproduce:

* Clone the latest version of Fuel DevOps form GitHub.
* Create environment (template is attached)
* Try to add slave by command dos.py slave-add

Expected results: environment gets the new slave.

Actual result: no new slave, error message.

Reproducibility: every time.

Workaround: clone an existing slave by virt-clone command.

Impact: Fuel DevOps isn't fully functional.

Description of the environment:
 Operation system: Ubuntu 14.04
 Versions of components: Fuel DevOps commit b6c9412
 Reference architecture:
 Network model: Linux bridges
 Related projects installed: Fuel QA
Additional information:

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/329368

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/329368
Committed: https://git.openstack.org/cgit/openstack/fuel-devops/commit/?id=4b4010cefe2dc6012738f06737071ce7e9894a6c
Submitter: Jenkins
Branch: master

commit 4b4010cefe2dc6012738f06737071ce7e9894a6c
Author: Anton Studenov <email address hidden>
Date: Tue Jun 14 13:47:18 2016 +0300

    Fix dos.py slave-add command

    - Fixed group.add_node call.
    - Added print message if group not found
    - Added get_available_slave_name to prevent
      using existing names
    - Added GROUP-NAME column to dos.py show

    Change-Id: Ifdfcf2cf059556b34c6b4c36834edd41895d738a
    Closes-Bug: #1583452