CNF-23049: Migrate away from deprecated ioutil

[sebrandon1]

ioutil has been deprecated since Go 1.16: https://go.dev/doc/go1.16#ioutil

Tracking issue: redhat-best-practices-for-k8s/telco-bot#52

Core refactoring: Replace ioutil usage with io and os equivalents

• Replaced all instances of ioutil.ReadFile with os.ReadFile for reading files, and ioutil.WriteFile with os.WriteFile for writing files in multiple files, such as dockerregistry.go, config.go, and their respective test files. [1] [2] [3] [4] [5] [6]
• Replaced all instances of ioutil.ReadAll with io.ReadAll for reading from readers and response bodies, affecting HTTP handlers, test helpers, and utility functions. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]
• Replaced ioutil.TempDir with os.MkdirTemp for creating temporary directories in tests. [1] [2]
• Replaced ioutil.Discard with io.Discard for discarding output in logger setup.
• Removed deprecated ioutil import statements and updated import blocks accordingly across all affected files. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15]

These changes ensure the codebase is compatible with newer Go versions and follows up-to-date language standards.

Summary by CodeRabbit

• Refactor
  • Updated file and response-body handling to use modern Go standard library APIs.
  • Removed reliance on deprecated legacy I/O helpers across registry, credential, client, testing, and tooling components.
  • Preserved existing behavior, error handling, and public interfaces.

[flavianmissi]

Thanks for taking the time to do this, @sebrandon1!

/lgtm
/retitle NO-JIRA: Migrate away from deprecated ioutil

[openshift-ci-robot]

@sebrandon1: This pull request explicitly references no jira issue.

Details

In response to this:

ioutil has been deprecated since Go 1.16: https://go.dev/doc/go1.16#ioutil

Tracking issue: redhat-best-practices-for-k8s/telco-bot#52

Core refactoring: Replace ioutil usage with io and os equivalents

• Replaced all instances of ioutil.ReadFile with os.ReadFile for reading files, and ioutil.WriteFile with os.WriteFile for writing files in multiple files, such as dockerregistry.go, config.go, and their respective test files. [1] [2] [3] [4] [5] [6]
• Replaced all instances of ioutil.ReadAll with io.ReadAll for reading from readers and response bodies, affecting HTTP handlers, test helpers, and utility functions. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]
• Replaced ioutil.TempDir with os.MkdirTemp for creating temporary directories in tests. [1] [2]
• Replaced ioutil.Discard with io.Discard for discarding output in logger setup.
• Removed deprecated ioutil import statements and updated import blocks accordingly across all affected files. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15]

These changes ensure the codebase is compatible with newer Go versions and follows up-to-date language standards.

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.

[flavianmissi]

/lgtm

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: flavianmissi, sebrandon1

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• OWNERS [flavianmissi]

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[flavianmissi]

this is an internal change.
/label px-approved
/label docs-approved

[openshift-ci]

New changes are detected. LGTM label has been removed.

[sebrandon1]

/retest

[openshift-ci-robot]

@sebrandon1: This pull request references CNF-23049 which is a valid jira issue.

Warning: The referenced jira issue has an invalid target version for the target branch this PR targets: expected the story to target the "5.0.0" version, but no target version was set.

Details

In response to this:

ioutil has been deprecated since Go 1.16: https://go.dev/doc/go1.16#ioutil

Tracking issue: redhat-best-practices-for-k8s/telco-bot#52

Core refactoring: Replace ioutil usage with io and os equivalents

• Replaced all instances of ioutil.ReadFile with os.ReadFile for reading files, and ioutil.WriteFile with os.WriteFile for writing files in multiple files, such as dockerregistry.go, config.go, and their respective test files. [1] [2] [3] [4] [5] [6]
• Replaced all instances of ioutil.ReadAll with io.ReadAll for reading from readers and response bodies, affecting HTTP handlers, test helpers, and utility functions. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]
• Replaced ioutil.TempDir with os.MkdirTemp for creating temporary directories in tests. [1] [2]
• Replaced ioutil.Discard with io.Discard for discarding output in logger setup.
• Removed deprecated ioutil import statements and updated import blocks accordingly across all affected files. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15]

These changes ensure the codebase is compatible with newer Go versions and follows up-to-date language standards.

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.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository: openshift/coderabbit/.coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: 2d8c51d7-c4da-4b46-9081-3929cfcdb4d7

📥 Commits

Reviewing files that changed from the base of the PR and between eb1b09d and eaa0661.

📒 Files selected for processing (15)

• pkg/cmd/dockerregistry/dockerregistry.go
• pkg/dockerregistry/server/blobdescriptorservice_test.go
• pkg/dockerregistry/server/configuration/configuration.go
• pkg/dockerregistry/server/signaturedispatcher.go
• pkg/dockerregistry/server/signaturedispatcher_test.go
• pkg/dockerregistry/server/util_test.go
• pkg/kubernetes-common/credentialprovider/config.go
• pkg/kubernetes-common/credentialprovider/config_test.go
• pkg/origin-common/clientcmd/clientcmd.go
• pkg/testframework/registry.go
• pkg/testutil/logrus.go
• test/integration/imagelayers/imagelayers_test.go
• test/integration/pullthrough/pullthrough_test.go
• test/integration/v2/v2_docker_registry_test.go
• tools/import-verifier/import-verifier.go

---

Walkthrough

Replaces deprecated io/ioutil helpers with io and os equivalents across registry runtime code, credential handling, client configuration, tests, integration tests, test utilities, and import-verification tooling.

Changes

io and os API modernization

Layer / File(s)	Summary
Runtime file and stream readers pkg/cmd/dockerregistry/dockerregistry.go, pkg/dockerregistry/server/..., pkg/kubernetes-common/credentialprovider/config.go, pkg/origin-common/clientcmd/clientcmd.go	Runtime reads now use os.ReadFile or io.ReadAll without changing surrounding control flow or error handling.
Test and integration read helpers pkg/dockerregistry/server/*_test.go, pkg/kubernetes-common/credentialprovider/config_test.go, test/integration/...	Tests replace deprecated read and temporary-file helpers with io.ReadAll, os.MkdirTemp, and os.WriteFile.
Test utilities and import verification pkg/testframework/registry.go, pkg/testutil/logrus.go, tools/import-verifier/import-verifier.go	Supporting utilities use io.ReadAll, io.Discard, and os.ReadFile.

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

Suggested reviewers: deads2k

🚥 Pre-merge checks | ✅ 14 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 28.57% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (14 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 PR’s main change: replacing deprecated ioutil usage across the codebase.
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	No Ginkgo titles were added in the touched tests; the only subtest names are static literals like 'credential present on node'.
Test Structure And Quality	✅ Passed	Touched tests use plain testing.T, not Ginkgo; no Describe/It/Eventually or cluster-wait patterns to assess.
Microshift Test Compatibility	✅ Passed	PASS: The diff only swaps ioutil for io/os helpers in existing tests; no new Ginkgo specs, MicroShift guards, or unsupported OpenShift APIs were added.
Single Node Openshift (Sno) Test Compatibility	✅ Passed	No new Ginkgo e2e tests were added; the touched test files are plain testing tests and only swap ioutil for io/os APIs.
Topology-Aware Scheduling Compatibility	✅ Passed	Only ioutil-to-standard-library refactors in Go files/tests; no manifests, controllers, or scheduling constraints were added.
Ote Binary Stdout Contract	✅ Passed	No touched process-level entrypoint writes to stdout; the only main uses log.Printf/log.Fatalf (stderr), and test logger setup discards output.
Ipv6 And Disconnected Network Test Compatibility	✅ Passed	PASS: The PR only refactors ioutil to io/os; no new Ginkgo e2e tests or IPv4/public-registry assumptions were added in the diff.
No-Weak-Crypto	✅ Passed	Patch only replaces ioutil with io/os helpers; no weak crypto, custom crypto, or secret-comparison logic was added.
Container-Privileges	✅ Passed	Changed files are only Go source/tests replacing ioutil with io/os; no manifest changes or privileged/hostPID/hostNetwork/hostIPC/SYS_ADMIN settings found.
No-Sensitive-Data-In-Logs	✅ Passed	Touched hunks only replace ioutil with io/os equivalents; no new logging of passwords, tokens, PII, or hostnames was introduced.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

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[openshift-ci]

@sebrandon1: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/e2e-metal-ipi-ovn-ipv6	eaa0661	link	true	/test e2e-metal-ipi-ovn-ipv6
ci/prow/e2e-aws-ovn	eaa0661	link	true	/test e2e-aws-ovn
ci/prow/images	eaa0661	link	true	/test images
ci/prow/e2e-agnostic-image-registry	eaa0661	link	true	/test e2e-agnostic-image-registry
ci/prow/e2e-aws-upgrade	eaa0661	link	true	/test e2e-aws-upgrade
ci/prow/e2e-aws-image-registry	eaa0661	link	true	/test e2e-aws-image-registry
ci/prow/e2e-hypershift	eaa0661	link	true	/test e2e-hypershift

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.