[10.0 swarm] Nailgun sends wrong status about DPDK availability

[Sergey Novikov]

Detailed bug description:

The issue was found by https://product-ci.infra.mirantis.net/job/10.0.system_test.ubuntu.support_dpdk/204/testReport/

Steps to reproduce:

            1. Create new environment with VLAN segmentation for Neutron
            2. Set KVM as Hypervisor
            3. Enable 'experimental' feature group
            4. Add controller and compute nodes
            5. Check DPDK availability for node interfaces

Expected results:
DPDK is available
Actual result:
DPDK is not available
http://paste.openstack.org/show/604639/

NOTE: The issue is reproduced only by autotests (test group: "deploy_cluster_with_dpdk_vlan")

Additional information:

It seems a race condition. According to nailgun/api.log and log of system tests Nailgin is sending a wrong status about DPDK availability during some time.

[Fedor Zhadaev (fzhadaev)]

Cannot reproduce the bug using 1532 and 1542 ISOs. Please reopen it if it will be reproduced again.

[Sergey Novikov (snovikov)]

New failure https://product-ci.infra.mirantis.net/job/10.0.system_test.ubuntu.support_dpdk/210/testReport/(root)/deploy_cluster_with_dpdk_tun/