🐛 (CLI): Fix panic from unchecked type assertion in printDeprecationWarnings

[SebTardif]

Problem

In pkg/cli/cli.go line 586, printDeprecationWarnings uses bare type assertions:

if p != nil && p.(plugin.Deprecated) != nil && len(p.(plugin.Deprecated).DeprecationWarning()) > 0 {
    _, _ = fmt.Fprintf(os.Stderr, noticeColor, fmt.Sprintf(deprecationFmt, p.(plugin.Deprecated).DeprecationWarning()))
}

p.(plugin.Deprecated) without the comma-ok pattern panics at runtime if any resolved plugin does not implement the plugin.Deprecated interface. This can be triggered by external plugins (user-installed binaries) that do not implement Deprecated.

The safe comma-ok pattern is already used elsewhere in the same codebase:

• pkg/cli/root.go:180: if deprecated, ok := p.(plugin.Deprecated); ok {
• pkg/cli/init.go:102: if _, isDeprecated := p.(plugin.Deprecated); !isDeprecated {

The unsafe assertion on line 586 was introduced on 2023-03-20.

Fix

Use the comma-ok pattern (deprecated, ok := p.(plugin.Deprecated)), matching the style in root.go:180. This also eliminates three redundant type assertions per iteration by reusing the deprecated variable.

Verification

• make lint-fix: 0 issues
• go test ./pkg/cli/...: all pass

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: SebTardif
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[k8s-ci-robot]

Hi @SebTardif. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work.

Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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[camilamacedo86]

/ok-to-test

[SebTardif]

/retest

[SebTardif]

/retest

[SebTardif]

/retest

[k8s-ci-robot]

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

Test name	Commit	Details	Required	Rerun command
pull-kubebuilder-e2e-k8s-1-36-0	91c184b	link	true	/test pull-kubebuilder-e2e-k8s-1-36-0

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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.