Lint unused funcs

[sbueringer]

It would be great if we had a linter which detects unused funcs.

I recently opened a PR to drop some unused code in KCP: https://github.com/kubernetes-sigs/cluster-api/pull/7598

I found the following cases:

1. funcs which weren't used by anyone: e.g. ControlPlane.MachineInfrastructureTemplateRef
2. funcs which were only used test code: e.g. ControlPlane.NewMachine

I think if there is a linter 1. should be relatively easy to detect.

I'm not sure about 2., it could be that there are a lot of false positives as we probably have non-test code which is used as test utils in tests.

But even if we only find a linter for 1. it should be a good improvement

/kind feature

[sbueringer]

/triage accepted /help

[k8s-ci-robot]

@sbueringer: This request has been marked as needing help from a contributor.

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In response to [this](https://github.com/kubernetes-sigs/cluster-api/issues/7599): >/triage accepted >/help Instructions for interacting with me using PR comments are available [here](https://git.k8s.io/community/contributors/guide/pull-requests.md). If you have questions or suggestions related to my behavior, please file an issue against the [kubernetes/test-infra](https://github.com/kubernetes/test-infra/issues/new?title=Prow%20issue:) repository.

[Anddd7]

Hi team, i just analyzed the code with goland.inspection, report:

I can help fix some warnings if needed (starting from minor changes, e.g. comments, unused variables & parameters)

[sbueringer]

It would be really good to instead research specific linters. Discuss if we want to enable them and then open a PR to add the linter and fix the findings.

[Anddd7]

It would be really good to instead research specific linters. Discuss if we want to enable them and then open a PR to add the linter and fix the findings.

The ci configured golangci linters already, do you mean to add more linters or modify the settings of existing linters?

[sbueringer]

The Idea was to see if we can enable additional linters/ rules via golangcilint.

Note this might be tricky as I expect we have a lot of exported types/funcs that are only used by external consumers

[fabriziopandini]

/priority backlog