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
  • Modernized file, stream, and response-body handling across registry, credential, client, testing, and tooling components.
  • Replaced deprecated Go I/O helpers with supported standard library APIs.
  • Preserved existing functionality, configuration behavior, error handling, request processing, and public interfaces.
  • No user-facing behavior changes are expected from this maintenance update.

[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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[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: ac0bad06-cc03-454f-815f-ca416057b985

📥 Commits

Reviewing files that changed from the base of the PR and between a91ce6e and 6649974.

📒 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

🚧 Files skipped from review as they are similar to previous changes (15)

• pkg/testframework/registry.go
• pkg/origin-common/clientcmd/clientcmd.go
• pkg/cmd/dockerregistry/dockerregistry.go
• test/integration/imagelayers/imagelayers_test.go
• pkg/dockerregistry/server/blobdescriptorservice_test.go
• pkg/kubernetes-common/credentialprovider/config.go
• pkg/dockerregistry/server/signaturedispatcher_test.go
• test/integration/v2/v2_docker_registry_test.go
• tools/import-verifier/import-verifier.go
• pkg/dockerregistry/server/util_test.go
• pkg/dockerregistry/server/signaturedispatcher.go
• pkg/testutil/logrus.go
• pkg/dockerregistry/server/configuration/configuration.go
• test/integration/pullthrough/pullthrough_test.go
• pkg/kubernetes-common/credentialprovider/config_test.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/ioutil 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. Existing control flow and error handling remain unchanged.
Test and integration helpers pkg/dockerregistry/server/*_test.go, pkg/kubernetes-common/credentialprovider/config_test.go, test/integration/...	Tests replace deprecated helpers with io.ReadAll, os.MkdirTemp, and os.WriteFile.
Supporting utilities and tooling pkg/testframework/registry.go, pkg/testutil/logrus.go, tools/import-verifier/import-verifier.go	Supporting code uses 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 summarizes the migration from deprecated Go ioutil APIs, which is the main change in the pull request.
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 changes only io/os APIs and imports; changed test names are unchanged, and no Ginkgo imports or It/Describe/Context/When title calls exist.
Test Structure And Quality	✅ Passed	The PR only changes deprecated I/O calls. All changed tests use standard testing.T, not Ginkgo, and add no cluster waits or test-structure changes.
Microshift Test Compatibility	✅ Passed	The patch changes only existing files for ioutil-to-io/os substitutions; the parent-to-HEAD diff adds no Ginkgo tests or MicroShift-sensitive API/resource references.
Single Node Openshift (Sno) Test Compatibility	✅ Passed	The diff adds no Ginkgo tests. Changed test files retain existing Test(*testing.T) functions, and added lines only replace ioutil APIs; no SNO-sensitive assumptions were added.
Topology-Aware Scheduling Compatibility	✅ Passed	The PR changes only 15 Go files for ioutil API replacements; no manifests, operators, controllers, or scheduling constructs were added or modified.
Ote Binary Stdout Contract	✅ Passed	The PR only replaces ioutil APIs and sets logrus output to io.Discard; the OTE main is unchanged, and klog v2 defaults to stderr.
Ipv6 And Disconnected Network Test Compatibility	✅ Passed	The PR only modifies existing tests and replaces ioutil calls; it adds no Ginkgo e2e tests, IPv4 assumptions, or external connectivity.
No-Weak-Crypto	✅ Passed	The diff only replaces ioutil calls with io/os APIs; no MD5, SHA1, DES, RC4, Blowfish, ECB, custom crypto, or secret comparisons were added.
Container-Privileges	✅ Passed	The PR changes only Go source and test files. The diff adds no privilege controls, and the repository Dockerfiles set USER 1001.
No-Sensitive-Data-In-Logs	✅ Passed	The PR adds no sensitive-data logging. The diff only replaces deprecated I/O APIs and ioutil.Discard; existing log statements remain unchanged.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

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[coderabbitai]

Note

GitHub couldn't provide a complete incremental comparison for this pull request, so CodeRabbit is performing a full review instead. This review may take a little longer.

[sebrandon1]

Progress update: 5 of 19 PRs in this ioutil migration effort have merged! 🎉

Recently merged:

• console-operator#1072 ← newest (Aug 19)
• debug-tools#102 (Jul 8)
• openshift-controller-manager#422 (May 20)
• ptp-operator#642 (May 13)
• cluster-samples-operator#668 (May 4)

This PR has been rebased against the latest upstream and is ready for review.

Epic: CNF-23315

[openshift-ci]

@sebrandon1: all tests passed!

Full PR test history. Your PR dashboard.

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