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

[coderabbitai]

Walkthrough

Migrate deprecated ioutil package functions to their standard library equivalents: replacing ioutil.ReadFile with os.ReadFile and ioutil.TempFile with os.CreateTemp. Removes unused ioutil imports while preserving existing error handling and logic flow.

Changes

Cohort / File(s)	Summary
CA Bundle and Certificate File Reading pkg/controller/cabundleinjector/starter.go, pkg/controller/servingcert/starter/starter.go	Replace ioutil.ReadFile with os.ReadFile for reading CA bundle and intermediate certificate files. Remove unused ioutil import; relocate other imports as needed. Error handling and subsequent processing unchanged.
Test Utilities test/util/rotate.go	Replace ioutil.TempFile with os.CreateTemp for creating temporary certificate and key files. Remove ioutil import. Surrounding logic and error handling preserved.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

• Straightforward, mechanical API replacements (ioutil.ReadFile → os.ReadFile, ioutil.TempFile → os.CreateTemp)
• Consistent pattern applied across 3 files with no logic modifications
• Import cleanup only; no behavior changes or error handling modifications

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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📥 Commits

Reviewing files that changed from the base of the PR and between f5a143a and c6bfab3.

📒 Files selected for processing (3)

• pkg/controller/cabundleinjector/starter.go (2 hunks)
• pkg/controller/servingcert/starter/starter.go (1 hunks)
• test/util/rotate.go (2 hunks)

🧰 Additional context used

📓 Path-based instructions (1)

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-Focus on major issues impacting performance, readability, maintainability and security. Avoid nitpicks and avoid verbosity.

Files:

• pkg/controller/servingcert/starter/starter.go
• test/util/rotate.go
• pkg/controller/cabundleinjector/starter.go

🔇 Additional comments (4)

test/util/rotate.go (1)

61-61: LGTM! Correct migration from deprecated ioutil.TempFile.

The replacement of ioutil.TempFile with os.CreateTemp correctly follows the Go 1.16 deprecation guidance. The function signature and behavior are identical, and error handling is properly preserved.

Also applies to: 77-77

pkg/controller/servingcert/starter/starter.go (1)

105-105: LGTM! Correct migration from deprecated ioutil.ReadFile.

The replacement of ioutil.ReadFile with os.ReadFile correctly follows the Go 1.16 deprecation guidance. The function signature and behavior are identical, and the existing error handling (including os.IsNotExist check) continues to work correctly.

pkg/controller/cabundleinjector/starter.go (2)

10-11: LGTM! Import adjustment.

The import block reordering is clean and maintains proper organization.

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55-55: LGTM! Correct migration from deprecated ioutil.ReadFile.

All three replacements of ioutil.ReadFile with os.ReadFile correctly follow the Go 1.16 deprecation guidance. The function signature and behavior are identical, and the existing error handling (including os.IsNotExist check on line 67) continues to work correctly.

Also applies to: 61-61, 66-66

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[xingxingxia]

@sebrandon1 @coderabbitai

service-ca-operator/pkg/operator/v4_00_assets/bindata.go

Line 614 in f5a143a

err = ioutil.WriteFile(_filePath(dir, name), data, info.Mode())

has one ioutil.

[coderabbitai]

Tip

For best results, initiate chat on the files or code changes.

🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
# Check the specific file mentioned by the user
echo "=== Examining pkg/operator/v4_00_assets/bindata.go ==="
cat pkg/operator/v4_00_assets/bindata.go | head -20
echo ""
echo "=== Looking for ioutil usage around line 614 ==="
sed -n '610,620p' pkg/operator/v4_00_assets/bindata.go

echo ""
echo "=== Searching for all remaining ioutil usages in the codebase ==="
rg -n 'ioutil\.' --type=go

echo ""
echo "=== Checking if bindata.go is a generated file ==="
head -5 pkg/operator/v4_00_assets/bindata.go

Length of output: 1466

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@xingxingxia @sebrandon1 Good catch! I've verified that pkg/operator/v4_00_assets/bindata.go line 614 does indeed contain a remaining ioutil.WriteFile usage (and an io/ioutil import on line 15). This is actually the only remaining ioutil usage in the entire codebase.

However, this file is a generated file created by go-bindata, as indicated by the header comment:

// Code generated for package v4_00_assets by go-bindata DO NOT EDIT. (@generated)

To address this ioutil usage, you'll need to:

1. Regenerate the bindata file using the go-bindata tool (or its replacement) with updated code that uses os.WriteFile instead of ioutil.WriteFile
2. Check if you're using an older version of go-bindata that still generates ioutil calls, and update to a newer version if available
3. Alternatively, consider migrating to a more modern alternative like go:embed (introduced in Go 1.16) if feasible for your use case

Would you like me to help investigate the bindata generation process or search for the command/script that generates this file?

[sebrandon1]

Yes, this is bindata so I didn't edit that file.

[xingxingxia]

Maybe it needs regenerated to be updated?

[sebrandon1]

I think that's a good plan. I wonder if that should be a separate PR because regenerating might encompass more changes than just ioutil.