Comment 7 for bug 1533942

the root cause is that when run "Ensuring OVS bridge is properly setup" task, the openvswitch_db is not ready. Test in my local with verbose std output:

TASK: [neutron | Ensuring OVS bridge is properly setup] ***********************
<localhost> REMOTE_MODULE command docker exec openvswitch_db /usr/local/bin/kolla_ensure_openvswitch_configured br-ex eth1
<localhost> EXEC ['/bin/sh', '-c', 'mkdir -p $HOME/.ansible/tmp/ansible-tmp-1454488961.85-178457803469879 && echo $HOME/.ansible/tmp/ansible-tmp-1454488961.85-178457803469879']
<localhost> PUT /tmp/tmpMvPWW9 TO /root/.ansible/tmp/ansible-tmp-1454488961.85-178457803469879/command
<localhost> EXEC ['/bin/sh', '-c', u'LANG=en_US.UTF-8 LC_CTYPE=en_US.UTF-8 /usr/bin/python /root/.ansible/tmp/ansible-tmp-1454488961.85-178457803469879/command; rm -rf /root/.ansible/tmp/ansible-tmp-1454488961.85-178457803469879/ >/dev/null 2>&1']
changed: [localhost] => {"changed": true, "cmd": ["docker", "exec", "openvswitch_db", "/usr/local/bin/kolla_ensure_openvswitch_configured", "br-ex", "eth1"], "delta": "0:00:00.224143", "end": "2016-02-03 03:42:42.155264", "rc": 0, "start": "2016-02-03 03:42:41.931121", "stderr": "ovs-vsctl: unix:/var/run/openvswitch/db.sock: database connection failed (No such file or directory)\novs-vsctl: unix:/var/run/openvswitch/db.sock: database connection failed (No such file or directory)\novs-vsctl: unix:/var/run/openvswitch/db.sock: database connection failed (No such file or directory)", "stdout": "changed", "stdout_lines": ["changed"], "warnings": []}