NoPoolFound exception is catched outside listing endpoints

[Eva Balycheva]

See these lines:
https://github.com/openstack/zaqar/blob/master/zaqar/api/v2/endpoints.py#L76
https://github.com/openstack/zaqar/blob/master/zaqar/api/v2/endpoints.py#L764
https://github.com/openstack/zaqar/blob/master/zaqar/transport/wsgi/v2_0/subscriptions.py#L139

When you try to list resources in these lines, when there are no pools registered in Zaqar, you'll get 500 error response.

Solution:
Move these lines inside try blocks, so they will be catched. Write tests, so the problem will not occur ever again.

Same solution was recently applied to wsgi driver in this patch: https://review.openstack.org/#/c/269165/3/zaqar/transport/wsgi/v1_0/queues.py (Affects queue listing in APIs: v1, v1.1, v2.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/283184

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/283184
Committed: https://git.openstack.org/cgit/openstack/zaqar/commit/?id=e58bdc4bb72742f775c27a4b66090fea828a3837
Submitter: Jenkins
Branch: master

commit e58bdc4bb72742f775c27a4b66090fea828a3837
Author: Eva Balycheva <email address hidden>
Date: Mon Feb 22 20:24:08 2016 +0300

    Catch NoPoolFound on resource listing in transport

    For example, "queue_list" operation in Websocket transport should catch
    any storage errors to return 503 error response, but the line
    "queues = list(next(results))", which can throw NoPoolFound exception,
    is outside try block.

    This problem not only affects "queue_list" operation in Websocket
    transport, but also some other places.

    This patch moves such lines inside try blocks, so exception will be
    properly handled. This patch also adds tests for this specific case.

    Change-Id: I5557aee5c0e4c1127f54b2059164bd1a0627c89d
    Closes-Bug: 1538795

[Doug Hellmann (doug-hellmann)]

This issue was fixed in the openstack/zaqar 2.0.0.0b3 development milestone.