Error with command "fuel2 graph download"

[Mikhail Samoylov]

steps to reproduce:
1. Create cluster with 1 controller
2. Deploy cluster
3. Try to download deployment graph with command: fuel2 graph download

Actual result:
If command "fuel2 graph download --env 2 --all --file cluster_graph.yaml" has not option 'default' then deployment graph output file will be empty
http://paste.openstack.org/show/495680/
Expected result:
Output file not empty, contains deployment graph

iso: 250

[Bug Checker Bot (bug-checker)]

(This check performed automatically)
Please, make sure that bug description contains the following sections filled in with the appropriate data related to the bug you are describing:

steps to reproduce

For more detailed information on the contents of each of the listed sections see https://wiki.openstack.org/wiki/Fuel/How_to_contribute#Here_is_how_you_file_a_bug

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/319967

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/319967
Committed: https://git.openstack.org/cgit/openstack/fuel-web/commit/?id=e31b5b16ee3529cd835a05ec523c0c0731c0c671
Submitter: Jenkins
Branch: master

commit e31b5b16ee3529cd835a05ec523c0c0731c0c671
Author: Dmitry Guryanov <email address hidden>
Date: Tue May 31 14:13:32 2016 +0300

    Fix deployment_tasks api, when graph_type is an empty string

    Nailgun should treat and empty string, given to

    /clusters/(?P<obj_id>\d+)/deployment_tasks/?graph_type=$
    /clusters/(?P<obj_id>\d+)/deployment_tasks/plugins/?graph_type=$
    /clusters/(?P<obj_id>\d+)/deployment_tasks/release/?graph_type=$
    e.t.c.

    as default graph type. So let's convert some 'false'
    values to None in handlers.

    Change-Id: I238764d24fc14b2a41baaca37dabb6264e7e91d8
    Closes-Bug: #1576261

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/mitaka
Review: https://review.openstack.org/353464

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/353464
Committed: https://git.openstack.org/cgit/openstack/fuel-web/commit/?id=2a56355242f94144a49c8675ef854604a466b8ae
Submitter: Jenkins
Branch: stable/mitaka

commit 2a56355242f94144a49c8675ef854604a466b8ae
Author: Dmitry Guryanov <email address hidden>
Date: Thu Sep 1 19:57:22 2016 +0300

    Fix deployment_tasks api, when graph_type is an empty string

    Nailgun should treat and empty string, given to

    /clusters/(?P<obj_id>\d+)/deployment_tasks/?graph_type=$
    /clusters/(?P<obj_id>\d+)/deployment_tasks/plugins/?graph_type=$
    /clusters/(?P<obj_id>\d+)/deployment_tasks/release/?graph_type=$
    e.t.c.

    as default graph type. So let's convert some 'false'
    values to None in handlers.

    Change-Id: I238764d24fc14b2a41baaca37dabb6264e7e91d8
    Closes-Bug: #1576261
    (cherry picked from commit e31b5b16ee3529cd835a05ec523c0c0731c0c671)

[TatyanaGladysheva (tgladysheva)]

Verified on 9.1 snapshot #259.