[Bug 2150130] Re: --restart in ovn-controller leaves gateway ports active

Matthew Ruffell 2150130 at bugs.launchpad.net
Wed Jun 10 22:13:32 UTC 2026 

Hi Arif,

1) OVN is a openstack package, and the package git repository lives under the
~ubuntu-openstack-dev repository:

https://git.launchpad.net/~ubuntu-openstack-dev/ubuntu/+source/ovn

Please open a MR against this, for the stable/yoga branch.

2) For the debian/changelog, you don't really need to specify the Launchpad
bug twice, instead you can do something like the format:

  * Remove the --restart option in the systemd service to prevent the downed
    node from remaining on the LRP list even though an outage has occurred.
    (LP: #2150130)
    - d/ovn-host.preinst: Do not clear runtime state on package upgrade
    - d/ovn-host.ovn-controller.service: Remove the --restart option which
    was leaving records and no cleanups.
    
The first point gives us an idea of what the change does as a whole, and a user
who is reading apt changelog can have an idea of what the package does before
they install it.

3) I spent a long time figuring out when this change actually happened in
Ubuntu. Eventually we came along as discovered that this happened in debian
unstable in version 22.12.0-3 which eventually became 23.03.1-1ubuntu0.23.04.1
in Lunar. So all packages from Lunar onward carry this implementation. Please
mention this in your SRU template.

4) The Impact statement needs some revision:

- What is the real impact to the user? Why is this bad? If we try use the
first gateway and fail and then go onto the next one, it still works right?
Does this add latency or performance issues or what does the user actually see?

- You need to complete the last sentence, about what happens to the runtime
state on upgrade. What happens to the runtime state on upgrade, why is it bad?
Why do we need the preinstall file to make it all better?

5) The testcase statement needs some revision:

- Please add a section on testing the preinstall script to make sure it functions
as intended, and avoids the whole clearing of state problem on package upgrade.

6) The Where problems could occur statement needs a revision:

- You mention that we don't want to reintroduce bug 1940043, but what steps
does your SRU take to ensure this does not happen? 

- If a regression were to occur, what would it look like to users? How would
they know?

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https://bugs.launchpad.net/bugs/2150130

Title:
  --restart in ovn-controller leaves gateway ports active

Status in Ubuntu Cloud Archive:
  Fix Released
Status in Ubuntu Cloud Archive yoga series:
  In Progress
Status in ovn package in Ubuntu:
  Fix Released
Status in ovn source package in Jammy:
  In Progress

Bug description:
  [Impact]

  Currently, if an ovn controller node goes down and the node is in the
  list of the lrp gateways, then this is not removed from the list. This
  means it will still try and use this gateway, and fail, and go onto
  the next one if this was at the top of the priority list.

  What the back-port does is that it removes the --restart from the
  systemd. This then removes the gateway from the list, so OVN will not
  try to use this gateway port.

  On top of this, by removing the --restart, it can affect upgrades of
  the ovn package, to avoid this we add the d/ovn-host.preinst that
  prevents the runtime state of OVN at upgrade

  [Test Plan]

  * Install OpenStack using the default OpenStack bundles, ensure to have at least 2 or 3 nova-compute units.
  * Find the node that has the northbound database as well as the southbound database, and login to both of these. It could be that they are both on the same node.
  * Then run the following commands, with sample outputs

  ```
  root at juju-71c67f-3-lxd-2:~# ovn-nbctl lr-list
  8588bef1-b3fc-4097-87e7-2c34e26f4c69 (neutron-727e3681-8eb4-4025-aa54-046588a2c3ab)
  root at juju-71c67f-3-lxd-2:~# ovn-nbctl show 8588bef1-b3fc-4097-87e7-2c34e26f4c69
  router 8588bef1-b3fc-4097-87e7-2c34e26f4c69 (neutron-727e3681-8eb4-4025-aa54-046588a2c3ab) (aka provider-router)
      port lrp-3e157281-4075-456d-bc17-61c6fcb5ff1d
          mac: "fa:16:3e:9b:be:95"
          networks: ["10.0.22.1/24"]
      port lrp-35c4d398-9a43-4fbf-9781-bc4a6d8d4a38
          mac: "fa:16:3e:d0:25:3b"
          networks: ["192.168.21.1/24"]
      port lrp-7c725d10-8056-455d-a2d5-b84f33c16045
          mac: "fa:16:3e:81:04:03"
          networks: ["192.168.1.44/24"]
          gateway chassis: [as3-maas-node-03.maas as2-maas-node-04.maas as4-maas-node-03.maas as4-maas-node-04.maas as3-maas-node-06.maas]
      nat 3121ce08-9899-495b-b385-5ecf17be0c1b
          external ip: "192.168.1.44"
          logical ip: "192.168.21.0/24"
          type: "snat"
      nat 8323629e-dbcc-4a45-84a4-a90aa3859cd7
          external ip: "192.168.1.44"
          logical ip: "10.0.22.0/24"
          type: "snat"
      nat 8e54bb28-3418-4052-9dc8-3c4178225322
          external ip: "192.168.1.42"
          logical ip: "10.0.22.187"
          type: "dnat_and_snat"
  root at juju-71c67f-3-lxd-2:~# ovn-nbctl lrp-get-gateway-chassis lrp-7c725d10-8056-455d-a2d5-b84f33c16045
  lrp-7c725d10-8056-455d-a2d5-b84f33c16045_as3-maas-node-03.maas     5
  lrp-7c725d10-8056-455d-a2d5-b84f33c16045_as3-maas-node-06.maas     4
  lrp-7c725d10-8056-455d-a2d5-b84f33c16045_as4-maas-node-04.maas     3
  lrp-7c725d10-8056-455d-a2d5-b84f33c16045_as4-maas-node-03.maas     2
  lrp-7c725d10-8056-455d-a2d5-b84f33c16045_as2-maas-node-04.maas     1
  ```
  This shows that node as3-maas-node-03.maas has the highest priority
  * Now stop ovn-controller service on the the highest priority node, i.e. as3-maas-node-03.maas in this case
  * Now the output of the last command will still be the same. We should expect as3-maas-node-03.maas to be removed.
  * Now install the new package, and run through the same process, and we should see that the node is removed, and similar output to the one below should be seen.

  ```
  root at juju-71c67f-3-lxd-2:~# ovn-nbctl lrp-get-gateway-chassis lrp-7c725d10-8056-455d-a2d5-b84f33c16045
  lrp-7c725d10-8056-455d-a2d5-b84f33c16045_as3-maas-node-06.maas     5
  lrp-7c725d10-8056-455d-a2d5-b84f33c16045_as4-maas-node-04.maas     4
  lrp-7c725d10-8056-455d-a2d5-b84f33c16045_as4-maas-node-03.maas     3
  lrp-7c725d10-8056-455d-a2d5-b84f33c16045_as2-maas-node-04.maas     2
  lrp-7c725d10-8056-455d-a2d5-b84f33c16045_as1-maas-node-06.maas     1
  ```

  [Where problems could occur]

  The --restart flag was originally added the commit [1] & (LP:
  #1940043) to ensure that upgrades don't cause issues. So we could
  potentially have that issue.

  [1]
  https://git.launchpad.net/ubuntu/+source/ovn/commit/?h=import/21.09.0_git20210806.d08f89e21-0ubuntu1.1&id=d73df64c24f97b6133448b57cae8d82af51df1fe

  [Other Info]

  Related LP: 1940043

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