kubeadm: fix-certs-generation-for-external-etcd

[fabriziopandini]

What type of PR is this?
/kind bug

What this PR does / why we need it:
This PR fixes an error when using external etcd but storing some external etcd certificate in the /etcd/kuberentes/pki folder with the same name used by kubeadm for local etcd certificates.

Which issue(s) this PR fixes:
Fixes # kubernetes/kubeadm#1276

Does this PR introduce a user-facing change?:

This PR fixes an error when using external etcd but storing etcd certificates in the same folder and with the same name used by kubeadm for local etcd certificates; for an older version of kubeadm, the workaround is to avoid file name used by kubeadm for local etcd.

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

/sig cluster-lifecycle
/priority important-soon
/assign @neolit123 @rosti @yagonobre
/cc @seh

[k8s-ci-robot]

@fabriziopandini: GitHub didn't allow me to request PR reviews from the following users: seh.

Note that only kubernetes members and repo collaborators can review this PR, and authors cannot review their own PRs.

In response to this:

What type of PR is this?
/kind bug

What this PR does / why we need it:
This PR fixes an error when using external etcd but storing some external etcd certificate in the /etcd/kuberentes/pki folder with the same name used by kubeadm for local etcd certificates.

Which issue(s) this PR fixes:
Fixes # kubernetes/kubeadm#1276

Does this PR introduce a user-facing change?:

NONE

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

/sig cluster-lifecycle
/priority important-soon
/assign @neolit123 @rosti @yagonobre
/cc @seh

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/test-infra repository.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: fabriziopandini

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• cmd/kubeadm/OWNERS [fabriziopandini]

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[neolit123]

/lgtm
/hold
thanks @fabriziopandini
please add a release note.

[yagonobre]

/test pull-kubernetes-e2e-gce-device-plugin-gpu

[yagonobre]

Thanks @fabriziopandini
/lgtm

[neolit123]

/hold cancel