No networks found in fixed_network.py (list index out of range)

[Silvan Kaiser]

Starting from about 12 hours ago our ci system throws lots of IndexErrors:

 File "tempest/common/fixed_network.py", line 54, in get_tenant_network
        network = networks[0]
    IndexError: list index out of range

More detailed output can be found here: http://176.9.127.22:8081/refs-changes-35-155735-218/console.log.out
The whole bunch of logfiles for all components is here: http://176.9.127.22:8081/refs-changes-35-155735-218/
The tempest tests are running in fresh VM instances (Ubuntu 14.04) with current devstack set up from current source.

The failures seems to coincide with the merge of: https://review.openstack.org/#/c/159776/

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/168353

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/168353
Committed: https://git.openstack.org/cgit/openstack/tempest/commit/?id=03feae04e670e0f4f7a950628ce0c9ec3025fba1
Submitter: Jenkins
Branch: master

commit 03feae04e670e0f4f7a950628ce0c9ec3025fba1
Author: Matthew Treinish <email address hidden>
Date: Fri Mar 27 10:25:45 2015 -0400

    Handle fixed_network edge cases gracefully

    When we added support for using the fixed_network_name config option to
    specify the network to boot with in a multi-network env a couple of
    configuration edge cases were not taken into account. First the case
    of misconfiguration was not handled at all this would cause an ugly
    IndexError exception to be raised because no matches were found for
    the name specified in config. The other was since the default config
    option was set to 'private' and fixed network name is always used when
    configured the default for single network environments broke if the
    single network. This commit addresses these by removing the default
    value for fixed_network_name (and making the help more clear) and
    having fixed_network_name handle the misconfiguration case more
    clearly by raising an InvalidConfiguration exception.

    Change-Id: I06ac0605a1a7e35d1af9a93a3bfc387a78f8be1c
    Closes-Bug: #1437328