Fix kops update for OpenStack with LB

[ching-kuo]

In the last PR to support OVN provider for LB, listener will refer to
load balancer provider for ACL settings. While currently get listener
API returns empty Pools, which will cause nil pointer dereference when
referring Pool.Loadbalancer.Provider.

This commit fix this issue by getting pool information with
DefaultPoolID when Pools is empty. As I added GetPool function, the
origin GetPool function is renamed to GetPoolMember.

[k8s-ci-robot]

Hi @ching-kuo. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[ching-kuo]

https://docs.openstack.org/api-ref/load-balancer/v2/?expanded=show-listener-details-detail#show-listener-details

I don't see pools returned in the API document, the gophercloud implementation of that line is added 4 years ago. Maybe the API spec has changed.

If each listener only correspond to one pool we can remove the logic to loop though pools

[hakman]

/ok-to-test

[zetaab]

looks good from my perspective.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: zetaab

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• upup/pkg/fi/cloudup/openstack/OWNERS [zetaab]
• upup/pkg/fi/cloudup/openstacktasks/OWNERS [zetaab]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment