Adds the ability to configure the Kubernetes API server with a structured authorization configuration file.
Structured AuthorizationConfiguration is a new feature in Kubernetes v1.29+ (GA in v1.32) that configures the API server's authorization modes with a structured configuration file.
AuthorizationConfiguration files offer features not available with the `--authorization-mode` flag, although Kubespray supports both methods and authorization-mode remains the default for now.
Note: Because the `--authorization-config` and `--authorization-mode` flags are mutually exclusive, the `authorization_modes` ansible variable is ignored when `kube_apiserver_use_authorization_config_file` is set to true. The two features cannot be used at the same time.
Docs: https://kubernetes.io/docs/reference/access-authn-authz/authorization/#configuring-the-api-server-using-an-authorization-config-file
Blog + Examples: https://kubernetes.io/blog/2024/04/26/multi-webhook-and-modular-authorization-made-much-easier/
KEP: https://github.com/kubernetes/enhancements/tree/master/keps/sig-auth/3221-structured-authorization-configuration
I tested this all the way back to k8s v1.29 when AuthorizationConfiguration was first introduced as an alpha feature, although v1.29 required some additional workarounds with `kubeadm_patches`, which I included in example comments.
I also included some example comments with CEL expressions that allowed me to configure webhook authorizers without hitting kubeadm 1.29+ issues that block cluster creation and upgrades such as this one: https://github.com/kubernetes/cloud-provider-openstack/issues/2575.
My workaround configures the webhook to ignore requests from kubeadm and system components, which prevents fatal errors from webhooks that are not available yet, and should be authorized by Node or RBAC anyway.
v1beta4 has changed a lot in this file (e.g. ExtraArgs etc.), so it was implemented in separate files.
Signed-off-by: ChengHao Yang <17496418+tico88612@users.noreply.github.com>
