kubeadm: fix a regression in "kubeadm init" where --kubeconfig is ignored

[avorima]

What type of PR is this?

/kind bug
/kind regression

What this PR does / why we need it:

Don't create admin rolebindings when --kubeconfig is set to a non-default value.
This allows kubeadm init to be invoked with a custom kubeconfig again.

Which issue(s) this PR fixes:

Fixes kubernetes/kubeadm#2992

Special notes for your reviewer:

I built and tested the kubeadm binary.

@neolit123

Does this PR introduce a user-facing change?

fixes a 1.29 regression in "kubeadm init" that caused a user-specified --kubeconfig file to be ignored.

[k8s-ci-robot]

Hi @avorima. Thanks for your PR.

I'm waiting for a kubernetes 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.

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[neolit123]

/hold for review
/cc @SataQiu

/ok-to-test

[neolit123]

can we actually verify that the initOptions.kubeconfigPath is used here?
one way would be with httptest, i guess.

[avorima]

something like this?

	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodHead {
			w.WriteHeader(http.StatusMethodNotAllowed)
		}
	}))
	defer ts.Close()

...

	result := client.Discovery().RESTClient().Verb("HEAD").Do(context.Background())
	if err := result.Error(); err != nil {
		t.Fatalf("REST client request returned unexpected error: %v", err)
	}

[neolit123]

SGTM!

(please keep the commits squashed to 1)

[neolit123]

/triage accepted
/priority important-longterm

[neolit123]

/release-note-edit

kubeadm: fix a regression in "kubeadm init" that caused a user-specified --kubeconfig file to be ignored.

[neolit123]

/uncc @chendave

[neolit123]

please squash the commits to 1
/approve

leaving LGTM to @SataQiu
do you think this is good, as is and we can backport it?

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: avorima, neolit123

The full list of commands accepted by this bot can be found here.

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Needs approval from an approver in each of these files:

• cmd/kubeadm/OWNERS [neolit123]

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[neolit123]

/retitle kubeadm: fix a regression in "kubeadm init" where --kubeconfig is ignored

[avorima]

I suppose this change won't make it into 1.29.1, right? @neolit123 @SataQiu
https://kubernetes.io/releases/patch-releases/

[neolit123]

I suppose this change won't make it into 1.29.1, right? @neolit123 @SataQiu https://kubernetes.io/releases/patch-releases/

no, we missed the deadline last friday.
it can land in .2

[neolit123]

/lgtm

let's go ahead and merge this.
it can catch the next cherry pick deadline
https://kubernetes.io/releases/patch-releases/#upcoming-monthly-releases

@avorima
would you like to send the cherry pick for release-1.29 as well?
you can try https://github.com/kubernetes/kubernetes/blob/master/hack/cherry_pick_pull.sh
if not a manual cherry pick PR can work too.

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: e56cdeb6ce3d57987755569b24c0dc84eea1214b

[neolit123]

/hold cancel

[avorima]

sure, i'll do the cherry pick

[liggitt]

Thanks for the PR, please update the release note with the minor version the regression was introduced (for example, "fixes a 1.29 regression…")

[liggitt]

And update the release note in the cherry-pick(s) as well

[avorima]

@liggitt Thanks for you feedback. I updated both release notes