New experimental-upload-certs flag handling of external etcd certs

[krisdock]

What keywords did you search in kubeadm issues before filing this one?

experimental
external etcd

Is this a BUG REPORT or FEATURE REQUEST?

Choose one: BUG REPORT

Versions

kubeadm version (use kubeadm version): 1.14

Environment:

• Kubernetes version (use kubectl version): 1.14
• Cloud provider or hardware configuration: GCE nodes
• OS (e.g. from /etc/os-release): CentOS Linux release 7.6.1810 (Core)
• Kernel (e.g. uname -a): 3.10.0-957.5.1.el7.x86_64
• Others:

What happened?

I have a cluster utilizing an external etcd cluster. I attempted to add a second control plane node with the --certificate-key flag. The join fails with:

[preflight] Running pre-flight checks before initializing the new control plane instance
	[WARNING ExternalEtcdClientCertificates]: /etc/kubernetes/pki/etcd/ca.crt doesn't exist
	[WARNING ExternalEtcdClientCertificates]: /etc/kubernetes/pki/apiserver-etcd-client.crt doesn't exist
	[WARNING ExternalEtcdClientCertificates]: /etc/kubernetes/pki/apiserver-etcd-client.key doesn't exist
error execution phase preflight: [preflight] Some fatal errors occurred:
	[ERROR ExternalEtcdVersion]: couldn't load external etcd's server certificate /etc/kubernetes/pki/etcd/ca.crt: open /etc/kubernetes/pki/etcd/ca.crt: no such file or directory

If I skip the ExternalEtcdClientCertificates and ExternalEtcdVersion preflight checks, the join works and the external etcd certs/keys are properly copied over.

What you expected to happen?

I shouldn't have to skip those checks if using the new experimental-upload-certs and cert-key flags/features.

How to reproduce it (as minimally and precisely as possible)?

Init a cluster with the --experimental-upload-certs flag that is using an external etcd cluster then use the control plane join command from the output to try to join another control plane node.

Anything else we need to know?

[fabriziopandini]

/assign

[fabriziopandini]

/lifecycle active

[fabriziopandini]

/close
fixed on master; cherry pick for v1.14 kubernetes/kubernetes#75851

[k8s-ci-robot]

@fabriziopandini: Closing this issue.

In response to this:

/close
fixed on master; cherry pick for v1.14 kubernetes/kubernetes#75851

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