fix: skip removing nics from lb if there will be no nics in the backe…

[nilo19]

…nd pool

What type of PR is this?

/kind bug

What this PR does / why we need it:

We used to remove the nics from the lb backend pool if the corresponding VM is not ready. However, if all nodes in the pool go into not ready state at a time, the connection will be completely lost. This PR skips the removal if the backend pool will be empty after the operation. If the vms are not found, the nics will be removed, even if the pool will be empty, because in this case the nics are not supposed to exist any more.

The manual removal by the node label node.kubernetes.io/exclude-from-external-load-balancers=true will also be ignored in this case.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?

fix: skip removing nics from lb if there will be no nics in the backend pool

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: nilo19

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:

• OWNERS [nilo19]

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

[MartinForReal]

/retest

[nilo19]

/retest

[MartinForReal]

/retest

[feiskyer]

Thanks for the fix

/lgtm

[nilo19]

/test pull-cloud-provider-azure-e2e-capz

[nilo19]

/test pull-cloud-provider-azure-e2e-ccm-capz

[nilo19]

/test pull-cloud-provider-azure-e2e-ccm-vmss-capz

[nilo19]

/retest

[nilo19]

/retest

[nilo19]

/cherrypick release-1.23

[nilo19]

/cherrypick release-1.24

[nilo19]

/cherrypick release-1.25

[nilo19]

/cherrypick release-1.26

[k8s-infra-cherrypick-robot]

@nilo19: #3212 failed to apply on top of branch "release-1.23":

Applying: fix: skip removing nics from lb if there will be no nics in the backend pool
Using index info to reconstruct a base tree...
M	pkg/provider/azure_loadbalancer_backendpool.go
M	pkg/provider/azure_loadbalancer_backendpool_test.go
M	tests/e2e/network/ensureloadbalancer.go
Falling back to patching base and 3-way merge...
Auto-merging tests/e2e/network/ensureloadbalancer.go
Auto-merging pkg/provider/azure_loadbalancer_backendpool_test.go
CONFLICT (content): Merge conflict in pkg/provider/azure_loadbalancer_backendpool_test.go
Auto-merging pkg/provider/azure_loadbalancer_backendpool.go
CONFLICT (content): Merge conflict in pkg/provider/azure_loadbalancer_backendpool.go
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 fix: skip removing nics from lb if there will be no nics in the backend pool
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

/cherrypick release-1.23

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.

[k8s-infra-cherrypick-robot]

@nilo19: #3212 failed to apply on top of branch "release-1.24":

Applying: fix: skip removing nics from lb if there will be no nics in the backend pool
Using index info to reconstruct a base tree...
M	pkg/provider/azure_loadbalancer_backendpool.go
M	pkg/provider/azure_loadbalancer_backendpool_test.go
M	tests/e2e/network/ensureloadbalancer.go
Falling back to patching base and 3-way merge...
Auto-merging tests/e2e/network/ensureloadbalancer.go
Auto-merging pkg/provider/azure_loadbalancer_backendpool_test.go
CONFLICT (content): Merge conflict in pkg/provider/azure_loadbalancer_backendpool_test.go
Auto-merging pkg/provider/azure_loadbalancer_backendpool.go
CONFLICT (content): Merge conflict in pkg/provider/azure_loadbalancer_backendpool.go
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 fix: skip removing nics from lb if there will be no nics in the backend pool
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

/cherrypick release-1.24

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.

[k8s-infra-cherrypick-robot]

@nilo19: #3212 failed to apply on top of branch "release-1.25":

Applying: fix: skip removing nics from lb if there will be no nics in the backend pool
Using index info to reconstruct a base tree...
M	pkg/provider/azure_loadbalancer_backendpool.go
M	pkg/provider/azure_loadbalancer_backendpool_test.go
M	tests/e2e/network/ensureloadbalancer.go
Falling back to patching base and 3-way merge...
Auto-merging tests/e2e/network/ensureloadbalancer.go
Auto-merging pkg/provider/azure_loadbalancer_backendpool_test.go
CONFLICT (content): Merge conflict in pkg/provider/azure_loadbalancer_backendpool_test.go
Auto-merging pkg/provider/azure_loadbalancer_backendpool.go
CONFLICT (content): Merge conflict in pkg/provider/azure_loadbalancer_backendpool.go
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 fix: skip removing nics from lb if there will be no nics in the backend pool
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

/cherrypick release-1.25

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.

[k8s-infra-cherrypick-robot]

@nilo19: #3212 failed to apply on top of branch "release-1.26":

Applying: fix: skip removing nics from lb if there will be no nics in the backend pool
Using index info to reconstruct a base tree...
M	pkg/provider/azure_loadbalancer_backendpool.go
M	pkg/provider/azure_loadbalancer_backendpool_test.go
M	tests/e2e/network/ensureloadbalancer.go
Falling back to patching base and 3-way merge...
Auto-merging tests/e2e/network/ensureloadbalancer.go
Auto-merging pkg/provider/azure_loadbalancer_backendpool_test.go
CONFLICT (content): Merge conflict in pkg/provider/azure_loadbalancer_backendpool_test.go
Auto-merging pkg/provider/azure_loadbalancer_backendpool.go
CONFLICT (content): Merge conflict in pkg/provider/azure_loadbalancer_backendpool.go
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 fix: skip removing nics from lb if there will be no nics in the backend pool
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

/cherrypick release-1.26

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.