Neutron L3 Agent: Race condition with creation of public bridge

[Dave Tucker]

./stack.sh fails with the following error:

2014-06-10 00:30:24.107 | + neutron_plugin_configure_l3_agent
2014-06-10 00:30:24.109 | + _neutron_ovs_base_configure_l3_agent
2014-06-10 00:30:24.112 | + iniset /etc/neutron/l3_agent.ini DEFAULT external_network_bridge br-ex
2014-06-10 00:30:24.119 | + neutron-ovs-cleanup
2014-06-10 00:30:24.912 | + sudo ovs-vsctl --no-wait -- --may-exist add-br br-ex
2014-06-10 00:30:24.929 | + sudo ovs-vsctl --no-wait br-set-external-id br-ex bridge-id br-ex
2014-06-10 00:30:24.945 | + sudo ip addr flush dev br-ex
2014-06-10 00:30:25.052 | Device "br-ex" does not exist.

This can be seen on the OpenDaylight Jenkins CI for neutron.
https://jenkins.opendaylight.org/ovsdb/job/openstack-gerrit/643/consoleFull

The public bridge is actually created by "ovs-vsctl" and can be seen from "ovs-vsctl show"
There is a race condition here where the bridge is either not created of not up when the 'ip addr flush dev br-ex" command is issued which causes ./stack.sh to error out.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/99414

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/99414
Committed: https://git.openstack.org/cgit/openstack-dev/devstack/commit/?id=f60e8c0fbe84f58e416966cdf3f13f289717f6fc
Submitter: Jenkins
Branch: master

commit f60e8c0fbe84f58e416966cdf3f13f289717f6fc
Author: Dave Tucker <email address hidden>
Date: Wed Jun 11 17:02:24 2014 +0100

    Wait for OVS to reconfigure when creating PUBLIC_BRIDGE

    The '--no-wait' flag will not wait for ovs-vswitchd to reconfigure after
    changes have been made to the database. This causes a race condition as
    the bridge may or may not be up when 'ip addr flush dev $PUBLIC_BRIDGE' is
    called. This commit removes the '--no-wait' flag which is safe as the
    openvswitch services are already started earlier in stack.sh

    Change-Id: I73ef1b731295d03b0f064c5f786196284c3e39ce
    Closes-bug: #1328962