[OVN] Provider driver fails while LB VIP port already created

[Maciej Jozefczyk]

Sometimes there is a RACE condition on creation of VIP port that ends with exception and blocks LB stack creation.

Example error:

2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils [req-a1e64a8e-5971-4b2f-afdf-33e026f193d6 - 968cd882ee5145d4a3e30b9612b0cae0 - default default] Provider 'ovn' raised a driver error: An unknown driver e
rror occurred.: octavia_lib.api.drivers.exceptions.DriverError: ('An unknown driver error occurred.', IpAddressAlreadyAllocatedClient())
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils Traceback (most recent call last):
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils File "/usr/lib/python3.6/site-packages/networking_ovn/octavia/ovn_driver.py", line 1843, in create_vip_port
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils project_id, lb_id, vip_dict)['port']
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils File "/usr/lib/python3.6/site-packages/networking_ovn/octavia/ovn_driver.py", line 1523, in create_vip_port
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils return network_driver.neutron_client.create_port(port)
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils File "/usr/lib/python3.6/site-packages/neutronclient/v2_0/client.py", line 803, in create_port
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils return self.post(self.ports_path, body=body)
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils File "/usr/lib/python3.6/site-packages/neutronclient/v2_0/client.py", line 359, in post
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils headers=headers, params=params)
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils File "/usr/lib/python3.6/site-packages/neutronclient/v2_0/client.py", line 294, in do_request
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils self._handle_fault_response(status_code, replybody, resp)
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils File "/usr/lib/python3.6/site-packages/neutronclient/v2_0/client.py", line 269, in _handle_fault_response
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils exception_handler_v20(status_code, error_body)
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils File "/usr/lib/python3.6/site-packages/neutronclient/v2_0/client.py", line 93, in exception_handler_v20
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils request_ids=request_ids)
2020-01-17 08:57:10.331 24 ERROR octavia.api.drivers.utils neutronclient.common.exceptions.IpAddressAlreadyAllocatedClient: IP address 172.30.188.22 already allocated in subnet 6cdca17f-c896-4684-9feb-6d0aa4aa3cb

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/networking-ovn 7.1.0 release.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/708591

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/708591
Committed: https://git.openstack.org/cgit/openstack/ovn-octavia-provider/commit/?id=42106d4696aaa8e91e458783b15c90335ff5f7e3
Submitter: Zuul
Branch: master

commit 42106d4696aaa8e91e458783b15c90335ff5f7e3
Author: Maciej Józefczyk <email address hidden>
Date: Fri Jan 17 15:08:27 2020 +0000

    Don't fail if VIP already exist or has been deleted before

    Sometimes there is a race condition on creation of VIP port
    or deleting it that ends with exception and blocks LB stack
    creation / deletion.

    Because for now we don't have running master branch
    for OVN provider driver this change will be applied
    first on stable/train in networking-ovn tree and then cherry-picked.

    Change-Id: I2aaae7c407caba7a57e2ca2d4ed524f3bb63953f
    Closes-Bug: #1860141