test_add_list_remove_router_on_l3_agent intermittently failing for DVR+HA gate job

[venkata anil]

This test is intermittently failing [1] for dvr+ha gate job.
DVR+HA gate job will be running in a 3 node devstack setup. Two nodes will be running l3 agent in "dvr_snat" node and another in "dvr" mode.
In this job, for dvr routers, we call add_router_interface[2] and then add this router to l3 agent [3].
1) add_router_interface will by default add router to one of the dvr_snat agents, for example agent1
2) when the test is again trying to add explicitly the router to agent,
   a) if adding to same agent i.e agent1, then neutron skips this request [4], hence test passes
   b) if adding to other agent i.e agent2, then neutron raises exception [5], and test fails

Till now we have only two nodes(one dvr and another dvr-snat) in gate for dvr multi node setup. So this test is passing as we are trying to add to same snat agent(and neuron skips this request). As we are not really testing any functionality for dvr, we should skip this test for dvr routers.

[1] http://logs.openstack.org/33/383833/3/experimental/gate-tempest-dsvm-neutron-dvr-ha-multinode-full-ubuntu-xenial-nv/8862b07/logs/testr_results.html.gz
[2] https://github.com/openstack/tempest/blob/master/tempest/api/network/admin/test_l3_agent_scheduler.py#L84
[3] https://github.com/openstack/tempest/blob/master/tempest/api/network/admin/test_l3_agent_scheduler.py#L114
[4] https://github.com/openstack/neutron/blob/master/neutron/db/l3_agentschedulers_db.py#L154
[5] https://github.com/openstack/neutron/blob/master/neutron/db/l3_agentschedulers_db.py#L159

[Oleg Bondarev (obondarev)]

Legacy router will also be scheduled on interface adding, so I assume same issue applies to legacy routers as well. I believe the test should be updated to first list agents of the router and then do remove/add based on this info.

[Rodolfo Alonso (rodolfo-alonso-hernandez)]

Bug closed due to lack of activity, please feel free to reopen if needed.