[10.0 swarm][VXLAN] MTU for br-int is changed when instance is booted

[Sergey Novikov]

Detailed bug description:

The issue was found by [0]
Steps to reproduce:
            1. Create new environment with VXLAN segmentation for Neutron
            2. Add controller and compute nodes
            3. Enable OVS firewall driver for neutron security groups
            4. Run network verification
            5. Deploy environment
            6. Check MTU for br-int
            7. Boot an instance and repeat step #6

result of

step #6:
16: br-int: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1\ link/ether 2e:da:fd:ba:fc:4e brd ff:ff:ff:ff:ff:ff

step #7:
16: br-int: <BROADCAST,MULTICAST> mtu 1450 qdisc noop state DOWN mode DEFAULT group default qlen 1\ link/ether 2e:da:fd:ba:fc:4e brd ff:ff:ff:ff:ff:ff

if we destroy VM, mtu will recovery, and will be 1500
In this test [0] the check expect that mtu isn't changed

[0] - https://product-ci.infra.mirantis.net/job/10.0.system_test.ubuntu.ovs_firewall/35/testReport/(root)/deploy_non_ha_cluster_with_ovs_firewall_vxlan/

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/newton
Review: https://review.openstack.org/448545

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/ocata
Review: https://review.openstack.org/448550

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/448551

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/448545
Committed: https://git.openstack.org/cgit/openstack/fuel-qa/commit/?id=393ab927c9049e34c12a7cd0ddd781f87874a877
Submitter: Jenkins
Branch: stable/newton

commit 393ab927c9049e34c12a7cd0ddd781f87874a877
Author: Sergey Novikov <email address hidden>
Date: Wed Mar 22 15:59:29 2017 +0400

    Take into account that MTU isn't constant in case of VXLAN

    MTU of ovs bridge "br-int" changes when virtual iface
    for instance is created. It behavior breaks the check
    that gets difference between network interfaces
    before and after vm booting

    Change-Id: I294bc309e8b13a912994a2cf20140e08120d5bbe
    Closes-Bug: 1674620

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/448550
Committed: https://git.openstack.org/cgit/openstack/fuel-qa/commit/?id=695dc47176460fe9f73386f72a1d11dfbbb30f55
Submitter: Jenkins
Branch: stable/ocata

commit 695dc47176460fe9f73386f72a1d11dfbbb30f55
Author: Sergey Novikov <email address hidden>
Date: Wed Mar 22 15:59:29 2017 +0400

    Take into account that MTU isn't constant in case of VXLAN

    MTU of ovs bridge "br-int" changes when virtual iface
    for instance is created. It behavior breaks the check
    that gets difference between network interfaces
    before and after vm booting

    Change-Id: I294bc309e8b13a912994a2cf20140e08120d5bbe
    Closes-Bug: 1674620

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/448551
Committed: https://git.openstack.org/cgit/openstack/fuel-qa/commit/?id=be5872064d30d88b2331b7fa83235930b3527bbf
Submitter: Jenkins
Branch: master

commit be5872064d30d88b2331b7fa83235930b3527bbf
Author: Sergey Novikov <email address hidden>
Date: Wed Mar 22 15:59:29 2017 +0400

    Take into account that MTU isn't constant in case of VXLAN

    MTU of ovs bridge "br-int" changes when virtual iface
    for instance is created. It behavior breaks the check
    that gets difference between network interfaces
    before and after vm booting

    Change-Id: I294bc309e8b13a912994a2cf20140e08120d5bbe
    Closes-Bug: 1674620

[Dmitry Belyaninov (dbelyaninov)]

Verified on Newton.
Passed run:
https://product-ci.infra.mirantis.net/job/10.0.system_test.ubuntu.ovs_firewall/53/testReport/(root)/deploy_non_ha_cluster_with_ovs_firewall_vxlan/

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/fuel-qa ocata-eol release.