[release-4.22] OCPBUGS-88356: fix(cpo): deduplicate VPC endpoint subnets by AZ

[reedcort]

What this PR does / why we need it:

Backport of #8651 to release-4.22.

When a HCP cluster has multiple NodePools with subnets in the same AWS availability zone, the CPO's VPC endpoint
reconciliation fails indefinitely with DuplicateSubnetsInSameZone. This PR adds AZ-aware subnet deduplication
in the CPO using an in-memory cache on the reconciler.

Manually cherry-picked due to code structure differences between main and release-4.22 (endpoint logic is
inline in reconcileAWSEndpointService on 4.22 vs extracted into helper functions on main).

Which issue(s) this PR fixes:

Fixes OCPBUGS-88356

Special notes for your reviewer:

• Same logic as the main PR, adapted to the 4.22 code structure
• No API/CRD changes — uses in-memory cache for easy backporting
• ROSA managed policy update tracked in ROSAENG-57993

Checklist:

• Subject and description added to both, commit and PR.
• Relevant issues have been referenced.
• This change includes docs.
• This change includes unit tests.

[openshift-merge-bot]

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[openshift-ci]

Skipping CI for Draft Pull Request.
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[openshift-ci-robot]

@reedcort: This pull request references Jira Issue OCPBUGS-82443, which is invalid:

• expected the bug to target either version "4.22." or "openshift-4.22.", but it targets "5.0.0" instead
• expected the bug to be in one of the following states: NEW, ASSIGNED, POST, but it is MODIFIED instead
• release note text must be set and not match the template OR release note type must be set to "Release Note Not Required". For more information you can reference the OpenShift Bug Process.
• expected Jira Issue OCPBUGS-82443 to depend on a bug targeting a version in 5.0.0 and in one of the following states: MODIFIED, ON_QA, VERIFIED, but no dependents were found

Comment /jira refresh to re-evaluate validity if changes to the Jira bug are made, or edit the title of this pull request to link to a different bug.

The bug has been updated to refer to the pull request using the external bug tracker.

Details

In response to this:

What this PR does / why we need it:

Backport of #8651 to release-4.22.

When a HCP cluster has multiple NodePools with subnets in the same AWS availability zone, the CPO's VPC endpoint
reconciliation fails indefinitely with DuplicateSubnetsInSameZone. This PR adds AZ-aware subnet deduplication
in the CPO using an in-memory cache on the reconciler.

Manually cherry-picked due to code structure differences between main and release-4.22 (endpoint logic is
inline in reconcileAWSEndpointService on 4.22 vs extracted into helper functions on main).

Which issue(s) this PR fixes:

Fixes OCPBUGS-82443

Special notes for your reviewer:

• Same logic as the main PR, adapted to the 4.22 code structure
• No API/CRD changes — uses in-memory cache for easy backporting
• ROSA managed policy update tracked in ROSAENG-57993

Checklist:

• Subject and description added to both, commit and PR.
• Relevant issues have been referenced.
• This change includes docs.
• This change includes unit tests.

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 openshift-eng/jira-lifecycle-plugin repository.

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[reedcort]

/jira refresh

[openshift-ci-robot]

@reedcort: This pull request references Jira Issue OCPBUGS-82443, which is invalid:

• expected the bug to target only the "4.22.0" version, but multiple target versions were set
• expected the bug to be in one of the following states: NEW, ASSIGNED, POST, but it is MODIFIED instead
• release note text must be set and not match the template OR release note type must be set to "Release Note Not Required". For more information you can reference the OpenShift Bug Process.
• expected Jira Issue OCPBUGS-82443 to depend on a bug targeting a version in 5.0.0 and in one of the following states: MODIFIED, ON_QA, VERIFIED, but no dependents were found

Comment /jira refresh to re-evaluate validity if changes to the Jira bug are made, or edit the title of this pull request to link to a different bug.

Details

In response to this:

/jira refresh

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 openshift-eng/jira-lifecycle-plugin repository.

[reedcort]

/jira refresh

[openshift-ci-robot]

@reedcort: This pull request references Jira Issue OCPBUGS-82443, which is invalid:

• release note text must be set and not match the template OR release note type must be set to "Release Note Not Required". For more information you can reference the OpenShift Bug Process.
• expected Jira Issue OCPBUGS-82443 to depend on a bug targeting a version in 5.0.0 and in one of the following states: MODIFIED, ON_QA, VERIFIED, but no dependents were found

Comment /jira refresh to re-evaluate validity if changes to the Jira bug are made, or edit the title of this pull request to link to a different bug.

Details

In response to this:

/jira refresh

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 openshift-eng/jira-lifecycle-plugin repository.

[codecov]

Codecov Report

❌ Patch coverage is 84.41558% with 12 lines in your changes missing coverage. Please review.
✅ Project coverage is 35.49%. Comparing base (5cb8735) to head (f1455fa).
⚠️ Report is 7 commits behind head on release-4.22.

Files with missing lines	Patch %	Lines
cmd/infra/aws/iam.go	0.00%	6 Missing ⚠️
...ollers/awsprivatelink/awsprivatelink_controller.go	91.54%	6 Missing ⚠️

Additional details and impacted files

@@               Coverage Diff                @@
##           release-4.22    #8724      +/-   ##
================================================
+ Coverage         35.45%   35.49%   +0.04%     
================================================
  Files               767      767              
  Lines             93724    93798      +74     
================================================
+ Hits              33226    33291      +65     
- Misses            57785    57794       +9     
  Partials           2713     2713              

Files with missing lines	Coverage Δ
cmd/infra/aws/iam.go	28.91% <0.00%> (-0.12%)	⬇️
...ollers/awsprivatelink/awsprivatelink_controller.go	23.80% <91.54%> (+5.50%)	⬆️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[openshift-ci-robot]

@reedcort: This pull request references Jira Issue OCPBUGS-88356, which is invalid:

• expected the bug to target either version "4.22." or "openshift-4.22.", but it targets "5.0.0" instead
• release note text must be set and not match the template OR release note type must be set to "Release Note Not Required". For more information you can reference the OpenShift Bug Process.
• expected Jira Issue OCPBUGS-88356 to depend on a bug targeting a version in 5.0.0 and in one of the following states: MODIFIED, ON_QA, VERIFIED, but no dependents were found

Comment /jira refresh to re-evaluate validity if changes to the Jira bug are made, or edit the title of this pull request to link to a different bug.

The bug has been updated to refer to the pull request using the external bug tracker.

Details

In response to this:

What this PR does / why we need it:

Backport of #8651 to release-4.22.

When a HCP cluster has multiple NodePools with subnets in the same AWS availability zone, the CPO's VPC endpoint
reconciliation fails indefinitely with DuplicateSubnetsInSameZone. This PR adds AZ-aware subnet deduplication
in the CPO using an in-memory cache on the reconciler.

Manually cherry-picked due to code structure differences between main and release-4.22 (endpoint logic is
inline in reconcileAWSEndpointService on 4.22 vs extracted into helper functions on main).

Which issue(s) this PR fixes:

Fixes OCPBUGS-82443

Special notes for your reviewer:

• Same logic as the main PR, adapted to the 4.22 code structure
• No API/CRD changes — uses in-memory cache for easy backporting
• ROSA managed policy update tracked in ROSAENG-57993

Checklist:

• Subject and description added to both, commit and PR.
• Relevant issues have been referenced.
• This change includes docs.
• This change includes unit tests.

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 openshift-eng/jira-lifecycle-plugin repository.

[reedcort]

/jira refresh

[openshift-ci-robot]

@reedcort: This pull request references Jira Issue OCPBUGS-88356, which is invalid:

• release note text must be set and not match the template OR release note type must be set to "Release Note Not Required". For more information you can reference the OpenShift Bug Process.

Comment /jira refresh to re-evaluate validity if changes to the Jira bug are made, or edit the title of this pull request to link to a different bug.

Details

In response to this:

/jira refresh

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 openshift-eng/jira-lifecycle-plugin repository.

[reedcort]

/jira refresh

[openshift-ci-robot]

@reedcort: This pull request references Jira Issue OCPBUGS-88356, which is valid. The bug has been moved to the POST state.

7 validation(s) were run on this bug

• bug is open, matching expected state (open)
• bug target version (4.22.0) matches configured target version for branch (4.22.0)
• bug is in the state New, which is one of the valid states (NEW, ASSIGNED, POST)
• release note text is set and does not match the template
• dependent bug Jira Issue OCPBUGS-82443 is in the state MODIFIED, which is one of the valid states (MODIFIED, ON_QA, VERIFIED)
• dependent Jira Issue OCPBUGS-82443 targets the "5.0.0" version, which is one of the valid target versions: 5.0.0
• bug has dependents

Details

In response to this:

/jira refresh

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 openshift-eng/jira-lifecycle-plugin repository.

[openshift-ci-robot]

@reedcort: This pull request references Jira Issue OCPBUGS-88356, which is valid.

7 validation(s) were run on this bug

• bug is open, matching expected state (open)
• bug target version (4.22.0) matches configured target version for branch (4.22.0)
• bug is in the state POST, which is one of the valid states (NEW, ASSIGNED, POST)
• release note text is set and does not match the template
• dependent bug Jira Issue OCPBUGS-82443 is in the state MODIFIED, which is one of the valid states (MODIFIED, ON_QA, VERIFIED)
• dependent Jira Issue OCPBUGS-82443 targets the "5.0.0" version, which is one of the valid target versions: 5.0.0
• bug has dependents

Details

In response to this:

What this PR does / why we need it:

Backport of #8651 to release-4.22.

When a HCP cluster has multiple NodePools with subnets in the same AWS availability zone, the CPO's VPC endpoint
reconciliation fails indefinitely with DuplicateSubnetsInSameZone. This PR adds AZ-aware subnet deduplication
in the CPO using an in-memory cache on the reconciler.

Manually cherry-picked due to code structure differences between main and release-4.22 (endpoint logic is
inline in reconcileAWSEndpointService on 4.22 vs extracted into helper functions on main).

Which issue(s) this PR fixes:

Fixes OCPBUGS-88356

Special notes for your reviewer:

• Same logic as the main PR, adapted to the 4.22 code structure
• No API/CRD changes — uses in-memory cache for easy backporting
• ROSA managed policy update tracked in ROSAENG-57993

Checklist:

• Subject and description added to both, commit and PR.
• Relevant issues have been referenced.
• This change includes docs.
• This change includes unit tests.

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 openshift-eng/jira-lifecycle-plugin repository.

[openshift-ci-robot]

@reedcort: This pull request references Jira Issue OCPBUGS-88356, which is valid.

7 validation(s) were run on this bug

• bug is open, matching expected state (open)
• bug target version (4.22.0) matches configured target version for branch (4.22.0)
• bug is in the state POST, which is one of the valid states (NEW, ASSIGNED, POST)
• release note text is set and does not match the template
• dependent bug Jira Issue OCPBUGS-82443 is in the state MODIFIED, which is one of the valid states (MODIFIED, ON_QA, VERIFIED)
• dependent Jira Issue OCPBUGS-82443 targets the "5.0.0" version, which is one of the valid target versions: 5.0.0
• bug has dependents

The bug has been updated to refer to the pull request using the external bug tracker.

Details

In response to this:

/jira refresh

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 openshift-eng/jira-lifecycle-plugin repository.

[Nirshal]

/lgtm

[openshift-merge-bot]

Scheduling tests matching the pipeline_run_if_changed or not excluded by pipeline_skip_if_only_changed parameters:
/test e2e-aks
/test e2e-aws
/test e2e-aws-upgrade-hypershift-operator
/test e2e-azure-self-managed
/test e2e-kubevirt-aws-ovn-reduced
/test e2e-v2-aws

[reedcort]

/retest

[openshift-merge-robot]

Fix included in release 5.0.0-0.nightly-2026-06-12-141614

[reedcort]

/retest

[bryan-cox]

/retest

[reedcort]

/retest

[reedcort]

/retest

[reedcort]

/test e2e-aws
/test e2e-aws-upgrade-hypershift-operator
/test e2e-aks

[bryan-cox]

/retest

[reedcort]

/test e2e-aws-upgrade-hypershift-operator

[bryan-cox]

@reedcort let's not just spam retest without knowing what is wrong. There may be a legitimate issue here since this test has never passed on this PR.

[bryan-cox]

/test e2e-aws-upgrade-hypershift-operator

[devguyio]

/test e2e-aws-upgrade-hypershift-operator

[reedcort]

Test Evidence

Tested on a ROSA HCP 4.22.1 staging cluster with two subnets in the same AZ (us-east-2a).

AWSEndpointService spec shows both subnets:

subnetIDs: ["subnet-004ce799aaae2a8cc","subnet-0ab84217ba33a3613"]

Before — graceful degradation without ec2:DescribeSubnets in managed policy

The CPO attempts to deduplicate but DescribeSubnets is denied. It falls back to the original subnet list, and ModifyVpcEndpoint fails with DuplicateSubnetsInSameZone. This is the existing fallback behavior — no regression when the ROSA managed policy hasn't been updated yet.

{"level":"error","ts":"2026-06-26T14:33:37Z","msg":"failed to deduplicate subnets by AZ, proceeding with original list","controller":"awsendpointservice","controllerKind":"AWSEndpointService","name":"private-router","error":"failed to describe subnets for AZ deduplication: operation error EC2: DescribeSubnets, https response error StatusCode: 403, api error UnauthorizedOperation: You are not authorized to perform this operation."}

{"level":"error","ts":"2026-06-26T14:33:37Z","msg":"failed to modify vpc endpoint","controller":"awsendpointservice","controllerKind":"AWSEndpointService","name":"private-router","id":"vpce-05a945d43961ec1ec","addSubnets":["subnet-0ab84217ba33a3613"],"removeSubnets":[],"addSG":[],"error":"operation error EC2: ModifyVpcEndpoint, https response error StatusCode: 400, api error DuplicateSubnetsInSameZone: Found another VPC endpoint subnet in the availability zone of subnet-0ab84217ba33a3613."}

Condition:

AWSEndpointAvailable=False  failed to modify vpc endpoint: DuplicateSubnetsInSameZone

After — with ec2:DescribeSubnets added to the CPO IAM role

After adding ec2:DescribeSubnets to the CPO role, the dedup resolves both subnets to us-east-2a, picks one, and the endpoint reconciles successfully.

{"level":"info","ts":"2026-06-26T14:49:53Z","msg":"endpoint exists","controller":"awsendpointservice","controllerKind":"AWSEndpointService","name":"private-router","endpointID":"vpce-05a945d43961ec1ec"}

{"level":"info","ts":"2026-06-26T14:49:53Z","msg":"endpoint subnets are unchanged","controller":"awsendpointservice","controllerKind":"AWSEndpointService","name":"private-router"}

Condition:

AWSEndpointAvailable=True

/verified by @reedcort — tested on ROSA HCP 4.22.1 staging cluster with two subnets in same AZ

[openshift-ci-robot]

@reedcort: This PR has been marked as verified by @reedcort — tested on ROSA HCP 4.22.1 staging cluster with two subnets in same AZ.

Details

In response to this:

Test Evidence

Tested on a ROSA HCP 4.22.1 staging cluster with two subnets in the same AZ (us-east-2a).

AWSEndpointService spec shows both subnets:

subnetIDs: ["subnet-004ce799aaae2a8cc","subnet-0ab84217ba33a3613"]

Before — graceful degradation without ec2:DescribeSubnets in managed policy

The CPO attempts to deduplicate but DescribeSubnets is denied. It falls back to the original subnet list, and ModifyVpcEndpoint fails with DuplicateSubnetsInSameZone. This is the existing fallback behavior — no regression when the ROSA managed policy hasn't been updated yet.

{"level":"error","ts":"2026-06-26T14:33:37Z","msg":"failed to deduplicate subnets by AZ, proceeding with original list","controller":"awsendpointservice","controllerKind":"AWSEndpointService","name":"private-router","error":"failed to describe subnets for AZ deduplication: operation error EC2: DescribeSubnets, https response error StatusCode: 403, api error UnauthorizedOperation: You are not authorized to perform this operation."}

{"level":"error","ts":"2026-06-26T14:33:37Z","msg":"failed to modify vpc endpoint","controller":"awsendpointservice","controllerKind":"AWSEndpointService","name":"private-router","id":"vpce-05a945d43961ec1ec","addSubnets":["subnet-0ab84217ba33a3613"],"removeSubnets":[],"addSG":[],"error":"operation error EC2: ModifyVpcEndpoint, https response error StatusCode: 400, api error DuplicateSubnetsInSameZone: Found another VPC endpoint subnet in the availability zone of subnet-0ab84217ba33a3613."}

Condition:

AWSEndpointAvailable=False  failed to modify vpc endpoint: DuplicateSubnetsInSameZone

After — with ec2:DescribeSubnets added to the CPO IAM role

After adding ec2:DescribeSubnets to the CPO role, the dedup resolves both subnets to us-east-2a, picks one, and the endpoint reconciles successfully.

{"level":"info","ts":"2026-06-26T14:49:53Z","msg":"endpoint exists","controller":"awsendpointservice","controllerKind":"AWSEndpointService","name":"private-router","endpointID":"vpce-05a945d43961ec1ec"}

{"level":"info","ts":"2026-06-26T14:49:53Z","msg":"endpoint subnets are unchanged","controller":"awsendpointservice","controllerKind":"AWSEndpointService","name":"private-router"}

Condition:

AWSEndpointAvailable=True

/verified by @reedcort — tested on ROSA HCP 4.22.1 staging cluster with two subnets in same AZ

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[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

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[openshift-ci]

@reedcort: all tests passed!

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[openshift-ci-robot]

@reedcort: Jira Issue Verification Checks: Jira Issue OCPBUGS-88356
✔️ This pull request was pre-merge verified.
✔️ All associated pull requests have merged.
✔️ All associated, merged pull requests were pre-merge verified.

Jira Issue OCPBUGS-88356 has been moved to the MODIFIED state and will move to the VERIFIED state when the change is available in an accepted nightly payload. 🕓

Details

In response to this:

What this PR does / why we need it:

Backport of #8651 to release-4.22.

When a HCP cluster has multiple NodePools with subnets in the same AWS availability zone, the CPO's VPC endpoint
reconciliation fails indefinitely with DuplicateSubnetsInSameZone. This PR adds AZ-aware subnet deduplication
in the CPO using an in-memory cache on the reconciler.

Manually cherry-picked due to code structure differences between main and release-4.22 (endpoint logic is
inline in reconcileAWSEndpointService on 4.22 vs extracted into helper functions on main).

Which issue(s) this PR fixes:

Fixes OCPBUGS-88356

Special notes for your reviewer:

• Same logic as the main PR, adapted to the 4.22 code structure
• No API/CRD changes — uses in-memory cache for easy backporting
• ROSA managed policy update tracked in ROSAENG-57993

Checklist:

• Subject and description added to both, commit and PR.
• Relevant issues have been referenced.
• This change includes docs.
• This change includes unit tests.

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 openshift-eng/jira-lifecycle-plugin repository.

[openshift-merge-robot]

Fix included in release 4.22.0-0.nightly-2026-06-28-145820