Fix candidate stanza resolution for stable streams

[hoxhaeris]

The candidate stanza in resolveUpgradeRelease constructs stream names as X.Y.0-0.<stream>, which works for nightly and CI streams but not for stable streams, which use the N-stable naming convention.

When openshift/release#82640 set stream: "stable" in the 5-dev-preview config, upgrade-major verification jobs got stuck at Pending because the release-controller looked up 4.22.0-0.stable instead of 4-stable.

This PR extracts a candidateStreamName helper that returns N-stable with a version prefix filter for stable streams, preserving the existing behavior for nightly and CI streams.

Summary by CodeRabbit

• Bug Fixes
  • Improved candidate upgrade detection for stable release streams using major-version naming.
  • Added version-prefix filtering to help select the correct candidate releases.
  • Preserved existing stream resolution for nightly and continuous-integration releases.
  • Improved error reporting when a matching upgrade release cannot be found.

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hoxhaeris

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

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [hoxhaeris]

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

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro Plus

Run ID: 16f7279e-a898-4951-9904-00f32ef09f18

📥 Commits

Reviewing files that changed from the base of the PR and between c99f3af and 7d3a839.

📒 Files selected for processing (2)

• cmd/release-controller/sync_verify.go
• cmd/release-controller/sync_verify_test.go

---

📝 Walkthrough

Walkthrough

Candidate upgrade resolution now derives stream names and version prefixes for stable, nightly, and CI streams. Release lookup uses these values. Tests cover version changes, prefixes, and architecture suffixes.

Changes

Candidate stream resolution

Layer / File(s)	Summary
Candidate stream name derivation cmd/release-controller/sync_verify.go	Added candidateStreamName for stable, nightly, and CI streams. Stable streams include the requested minor-version prefix.
Stream lookup integration and validation cmd/release-controller/sync_verify.go, cmd/release-controller/sync_verify_test.go	resolveUpgradeRelease passes the derived stream name and prefix to LatestForStream. Tests cover stream naming across release types, major-version changes, and arm64 suffixes.

Estimated code review effort: 2 (Simple) | ~10 minutes

Suggested reviewers: alexnpavel, bradmwilliams

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly describes the fix for candidate stanza resolution in stable streams.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[openshift-ci]

@hoxhaeris: all tests passed!

Full PR test history. Your PR dashboard.

Details

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-sigs/prow repository. I understand the commands that are listed here.

[hoxhaeris]

/hold

[bradmwilliams]

I'm leaning towards this not being a necessary fix as the candidate stanza was never intended for "stable" releases. To require releases from the "stable" line, users should specify a prerelease stanza, like:

"upgradeFromRelease": {
  "prerelease": {
    "version_bounds": {
      "lower": "4.22.0",
      "upper": "4.23.0"
    }
  }
},

[bradmwilliams]

That being said, the prerelease logic does need some attention at some point as it's completely hard-coded to only look at 4-stable