[FT] FdbInterfaceTestCase test cases failing when creating two VTI with the same VNI

[Rodolfo Alonso]

In "FdbInterfaceTestCase" test cases (no namespace scenario), can happen that two test cases are creating VXLAN interfaces in the kernel namespace (VTI) in the same VTEP and the same destination port (default=4789). In this case, the kernel will raise the exception errno.EEXIST (file already exists).

In order to avoid this problem, a random VNI could be used when creating the VXLAN interfaces.

LOGS:
[1]https://9722deaa313ebebb56dc-c08b881decb3106ff13d720dd4a26025.ssl.cf5.rackcdn.com/681846/5/check/neutron-functional-python27/c3dc48a/testr_results.html.gz

HOW TO TEST IT:
from neutron.agent.linux import ip_lib
from neutron.privileged.agent.linux import ip_lib as priv_ip_lib
ns_name = 'ns_test'
try:
    priv_ip_lib.remove_netns(ns_name)
except:
    pass
priv_ip_lib.create_netns(ns_name)
dev = 'device'
dev2 = 'device2'
dev_vxlan = 'device_vxlan'
dev_vxlan2 = 'device_vxlan2'
ip_wrapper = ip_lib.IPWrapper(ns_name)
ip_wrapper.add_dummy(dev)
ip_wrapper.add_dummy(dev2)
ip_device1 = ip_lib.IPDevice(dev, ns_name)
ip_device2 = ip_lib.IPDevice(dev2, ns_name)
ip_device1.link.set_up()
ip_device2.link.set_up()
ip_wrapper.add_vxlan(dev_vxlan, 100, dev=dev)
try:
    ip_wrapper.add_vxlan(dev_vxlan2, 100, dev=dev2)
except Exception as e:
    print(str(e))
priv_ip_lib.remove_netns(ns_name)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/684805

[Rodolfo Alonso (rodolfo-alonso-hernandez)]

NOTE: this code is NOT present in stable/stein. No backport is needed.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/684805
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=761b91fd221914ce06ded381264740abc29fe066
Submitter: Zuul
Branch: master

commit 761b91fd221914ce06ded381264740abc29fe066
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Wed Sep 25 16:23:31 2019 +0000

    Randomize VNI in FdbInterfaceTestCase

    Randomize VNI in FdbInterfaceTestCase to avoid clashes if several test
    cases are creating VXLAN interfaces in the kernel namespace at the
    same time.

    Change-Id: Ic90fa31aa15723eab7f518a42762a7f1c80ee736
    Closes-Bug: #1845354

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/train
Review: https://review.opendev.org/688153

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/688153
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=54c8943ab5a6b980212d9c4c94173dc6b41dc78d
Submitter: Zuul
Branch: stable/train

commit 54c8943ab5a6b980212d9c4c94173dc6b41dc78d
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Wed Sep 25 16:23:31 2019 +0000

    Randomize VNI in FdbInterfaceTestCase

    Randomize VNI in FdbInterfaceTestCase to avoid clashes if several test
    cases are creating VXLAN interfaces in the kernel namespace at the
    same time.

    Change-Id: Ic90fa31aa15723eab7f518a42762a7f1c80ee736
    Closes-Bug: #1845354
    (cherry picked from commit 761b91fd221914ce06ded381264740abc29fe066)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 15.0.1 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 16.0.0.0b1 development milestone.