OCPBUGS-90135: retry blob copy on dropped connections

[zaneb]

When downloading blobs from CDN, dropped connections result in io.ErrUnexpectedEOF being propagated up to the retry wrapper. Similarly, CDN connectivity issues can produce TLS alert errors. Neither was classified as retryable, making --retry-times a no-op for these common failure modes.

Summary by CodeRabbit

• Bug Fixes
  • Improved retry handling for mirror operations so some transient transfer and TLS errors are retried automatically instead of failing immediately.
  • Added support for retrying unexpected end-of-file errors and certain TLS alert failures, helping reduce occasional connection-related disruptions.

[openshift-ci-robot]

@zaneb: This pull request references Jira Issue OCPBUGS-90135, which is valid.

3 validation(s) were run on this bug

• bug is open, matching expected state (open)
• bug target version (5.0.0) matches configured target version for branch (5.0.0)
• bug is in the state POST, which is one of the valid states (NEW, ASSIGNED, POST)

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

Details

In response to this:

When downloading blobs from CDN, dropped connections result in io.ErrUnexpectedEOF being propagated up to the retry wrapper. Similarly, CDN connectivity issues can produce TLS alert errors. Neither was classified as retryable, making --retry-times a no-op for these common failure modes.

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

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Plan: Enterprise

Run ID: bdf75a23-7899-4ba7-a964-c841593f0ca7

📥 Commits

Reviewing files that changed from the base of the PR and between 507b46a and 6f83de3.

📒 Files selected for processing (1)

• internal/pkg/mirror/mirror.go

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Walkthrough

Mirror retry handling now treats unexpected EOF and TLS alert errors as retryable, while preserving the existing deadline, cancellation, and fallback retry classification paths.

Changes

Mirror retryability update

Layer / File(s)	Summary
Retry classification internal/pkg/mirror/mirror.go	isErrorRetryable adds io.ErrUnexpectedEOF and tls.AlertError to the retryable cases and keeps the existing deadline, cancellation, and fallback retry checks.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

🚥 Pre-merge checks | ✅ 15

✅ Passed checks (15 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly matches the main change: making blob copy retry on dropped connections.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
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.
Stable And Deterministic Test Names	✅ Passed	The PR only changes internal/pkg/mirror/mirror.go; no Ginkgo test titles are added or modified, so the naming rule is not implicated.
Test Structure And Quality	✅ Passed	No Ginkgo tests were added or modified; the PR only changes internal/pkg/mirror/mirror.go retry logic, so the test-quality check is not applicable.
Microshift Test Compatibility	✅ Passed	PR only changes internal/pkg/mirror/mirror.go; no new Ginkgo e2e tests or MicroShift-sensitive APIs/features were added.
Single Node Openshift (Sno) Test Compatibility	✅ Passed	PASS: PR only changes retry logic in internal/pkg/mirror/mirror.go; no new Ginkgo e2e tests or SNO-sensitive assumptions were added.
Topology-Aware Scheduling Compatibility	✅ Passed	Only internal/pkg/mirror/mirror.go changed, and it adds retryable error handling; no manifests/controllers/scheduling constraints were introduced.
Ote Binary Stdout Contract	✅ Passed	Changed code only extends retry classification in library code; no main/init/TestMain/suite stdout writes or stdout logging setup appears in the touched file.
Ipv6 And Disconnected Network Test Compatibility	✅ Passed	PASS: The PR only changes internal/pkg/mirror/mirror.go retry logic; no new Ginkgo e2e tests or network/IP assumptions were added.
No-Weak-Crypto	✅ Passed	mirror.go only adds retry handling for io.ErrUnexpectedEOF and tls.AlertError; no weak ciphers, custom crypto, or secret comparisons appear in the PR changes.
Container-Privileges	✅ Passed	PASS: The PR only changes retry logic in internal/pkg/mirror/mirror.go; no container/K8s manifest or securityContext privilege settings were introduced.
No-Sensitive-Data-In-Logs	✅ Passed	The PR only adds retry classification in mirror.go; it introduces no new logging calls or log messages exposing secrets or PII.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[openshift-ci]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: zaneb
Once this PR has been reviewed and has the lgtm label, please assign aguidirh for approval. For more information see the Code Review Process.

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[zaneb]

/cc @aguidirh @andfasano @bfournie

[openshift-ci]

@zaneb: all tests passed!

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[bfournie]

/lgtm