* Fix a race condition in which kubeadm only waits for the kubelets kubeconfig file when it has performed the TLS bootstrap, but wasn't waiting for certificates to be present in the filesystem ([#72030](https://github.com/kubernetes/kubernetes/pull/72030), [@ereslibre](https://github.com/ereslibre))

It could be another container, for example with <a href="https://traefik.io/" class="external-link" target="_blank">Traefik</a>, handling **HTTPS** and **automatic** acquisition of **certificates**.

/// tip

Traefik has integrations with Docker, Kubernetes, and others, so it's very easy to set up and configure HTTPS for your containers with it.

///

- Enforced kubelet to request serving certificates only once it has at least one IP address in the `.status.addresses` of its associated Node object. This avoids requesting DNS-only serving certificates before externally set addresses are in place. Until 1.33, the previous behavior can be opted back into by setting the deprecated `AllowDNSOnlyNodeCSR` feature gate to true...

- Kubeadm: during execution of the "check expiration" command, treat the etcd CA as external if there is a missing etcd CA key file (etcd/ca.key) and perform the proper validation on certificates signed by the etcd CA. Additionally, make sure that the CA for all...

* AWS kube-up: tolerate a lack of ephemeral volumes ([#23776](https://github.com/kubernetes/kubernetes/pull/23776), [@justinsb](https://github.com/justinsb))
* Fix so setup-files don't recreate/invalidate certificates that already exist ([#23550](https://github.com/kubernetes/kubernetes/pull/23550), [@luxas](https://github.com/luxas))



# v1.2.1

        * requests from a node for a TLS client certificate for itself are approved if the CSR creator has `create` permission on the `certificatesigningrequests` resource and the `selfnodeclient` subresource in the `certificates.k8s.io` API group

- Kubeadm: during execution of the "check expiration" command, treat the etcd CA as external if there is a missing etcd CA key file (etcd/ca.key) and perform the proper validation on certificates signed by the etcd CA. Additionally, make sure that the CA for all...

- Fix an error when using external etcd but storing etcd certificates in the same folder 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. ([#80867](https://github.com/kubernetes/kubernetes/pull/80867), [@fabriziopandini](https://github.c...

- Certificate handling improvements:
  - Renew certs as part of upgrade.
  - New `kubeadm alpha phase certs renew` command for renewing certificates.
  - Certificates created with kubeadm now have improved uniqueness of Distinguished Name fields.
- HA improvements:
  - `kubeadm join --experimental-control-plane` can now be used to join control plane instances to an existing cluster.

- Kubernetes 1.24 is built with go1.18, which will no longer validate certificates signed with a SHA-1 hash algorithm by default. See https://golang.org/doc/go1.18#sha1 for more details. If you are using certificates like this in admission or conversion ([#109024](https://github.com/kubernetes/kubernetes/pull/109024), [@stlaz](https://github.com/stlaz))