Unit tests using fake_port1 and fake_port2 global variables are flaky

[Antonio Ojea]

The unit test test_enable_dhcp_helper_enable_metadata_nonisolated_dist_network modifies the global variables fake_port1, fake_port2, creating flakiness on unit tests that use those variables when execured in environments with high concurrency.

How to reproduce:

Run unit tests on following patch https://review.openstack.org/#/c/626641 with the following commands:

source .tox/py27/bin/activate
stestr run --concurrency=12 --until-failure neutron.tests.unit.agent.dhcp.test_agent.TestDhcpAgentEventHandler

After several iterations, the test port_create_end fails. Debugging the failure you can see that the ports that fail are different than the configured in the global variables, they have been modified by test_enable_dhcp_helper_enable_metadata_nonisolated_dist_network

Reference: https://rbtcollins.wordpress.com/2015/12/02/diagnosing-flaky-tests/

[Antonio Ojea (aojea)]

Fix proposed https://review.openstack.org/#/c/627087/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/627087
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=e83e5618b7ca71fb96bf460922480b9808b431b6
Submitter: Zuul
Branch: master

commit e83e5618b7ca71fb96bf460922480b9808b431b6
Author: aojeagarcia <email address hidden>
Date: Sun Dec 23 23:43:38 2018 +0100

    Don't modify global variables in unit tests

    The unit test
    test_enable_dhcp_helper_enable_metadata_nonisolated_dist_network
    modifies the global variables fake_port1, fake_port2, creating flakiness
    on unit tests that use those variables when execured in environments
    with high concurrency.

    Creating a deepcopy of the variable avoid that those changes can be
    propagated to other unit tests.

    Closes-Bug: #1809643

    Change-Id: Idfd0e99739952baf4d7b545b406cd1b251deb5f8
    Signed-off-by: aojeagarcia <email address hidden>

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/rocky
Review: https://review.openstack.org/627302

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/pike
Review: https://review.openstack.org/627303

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/ocata
Review: https://review.openstack.org/627304

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/627302
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=684b10234ed60ca63e8f42ab3af682a8241456d6
Submitter: Zuul
Branch: stable/rocky

commit 684b10234ed60ca63e8f42ab3af682a8241456d6
Author: aojeagarcia <email address hidden>
Date: Sun Dec 23 23:43:38 2018 +0100

    Don't modify global variables in unit tests

    The unit test
    test_enable_dhcp_helper_enable_metadata_nonisolated_dist_network
    modifies the global variables fake_port1, fake_port2, creating flakiness
    on unit tests that use those variables when execured in environments
    with high concurrency.

    Creating a deepcopy of the variable avoid that those changes can be
    propagated to other unit tests.

    Closes-Bug: #1809643

    Change-Id: Idfd0e99739952baf4d7b545b406cd1b251deb5f8
    Signed-off-by: aojeagarcia <email address hidden>
    (cherry picked from commit e83e5618b7ca71fb96bf460922480b9808b431b6)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/queens
Review: https://review.openstack.org/630403

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/627304
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=4c07f8ad356023b93a22326e00b2eee1e95eae7a
Submitter: Zuul
Branch: stable/ocata

commit 4c07f8ad356023b93a22326e00b2eee1e95eae7a
Author: aojeagarcia <email address hidden>
Date: Sun Dec 23 23:43:38 2018 +0100

    Don't modify global variables in unit tests

    The unit test
    test_enable_dhcp_helper_enable_metadata_nonisolated_dist_network
    modifies the global variables fake_port1, fake_port2, creating flakiness
    on unit tests that use those variables when execured in environments
    with high concurrency.

    Creating a deepcopy of the variable avoid that those changes can be
    propagated to other unit tests.

    Closes-Bug: #1809643

    Change-Id: Idfd0e99739952baf4d7b545b406cd1b251deb5f8
    Signed-off-by: aojeagarcia <email address hidden>
    (cherry picked from commit e83e5618b7ca71fb96bf460922480b9808b431b6)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/630403
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=44441bee0b20e476284111efe03a416c198d9933
Submitter: Zuul
Branch: stable/queens

commit 44441bee0b20e476284111efe03a416c198d9933
Author: aojeagarcia <email address hidden>
Date: Sun Dec 23 23:43:38 2018 +0100

    Don't modify global variables in unit tests

    The unit test
    test_enable_dhcp_helper_enable_metadata_nonisolated_dist_network
    modifies the global variables fake_port1, fake_port2, creating flakiness
    on unit tests that use those variables when execured in environments
    with high concurrency.

    Creating a deepcopy of the variable avoid that those changes can be
    propagated to other unit tests.

    Closes-Bug: #1809643

    Change-Id: Idfd0e99739952baf4d7b545b406cd1b251deb5f8
    Signed-off-by: aojeagarcia <email address hidden>
    (cherry picked from commit e83e5618b7ca71fb96bf460922480b9808b431b6)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/627303
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=dab82d56c4559a921ed801815c220812742a9c11
Submitter: Zuul
Branch: stable/pike

commit dab82d56c4559a921ed801815c220812742a9c11
Author: aojeagarcia <email address hidden>
Date: Sun Dec 23 23:43:38 2018 +0100

    Don't modify global variables in unit tests

    The unit test
    test_enable_dhcp_helper_enable_metadata_nonisolated_dist_network
    modifies the global variables fake_port1, fake_port2, creating flakiness
    on unit tests that use those variables when execured in environments
    with high concurrency.

    Creating a deepcopy of the variable avoid that those changes can be
    propagated to other unit tests.

    Closes-Bug: #1809643

    Change-Id: Idfd0e99739952baf4d7b545b406cd1b251deb5f8
    Signed-off-by: aojeagarcia <email address hidden>
    (cherry picked from commit e83e5618b7ca71fb96bf460922480b9808b431b6)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 14.0.0.0b2 development milestone.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 11.0.7 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 13.0.3 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 12.0.6 release.

[OpenStack Infra (hudson-openstack)]

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