k8s-1.30: enable kubelet drop-in config files

We can now use a proper API for customizations. See follow-up commits.

Signed-off-by: Victor Toso <[email protected]>

cluster-provision/k8s/1.30/k8s_provision.sh

@@ -148,9 +148,14 @@ patch $cni_manifest_ipv6 $cni_ipv6_diff
 
 cp /tmp/local-volume.yaml /provision/local-volume.yaml
 
+# Create drop-in config files for kubelet
+# https://kubernetes.io/docs/tasks/administer-cluster/kubelet-config-file/#kubelet-conf-d
+kubelet_conf_d="/etc/kubernetes/kubelet.conf.d"
+mkdir -m 644 $kubelet_conf_d
+
 # TODO use config file! this is deprecated
 cat <<EOT >/etc/sysconfig/kubelet
-KUBELET_EXTRA_ARGS=--cgroup-driver=systemd --runtime-cgroups=/systemd/system.slice  --fail-swap-on=false --kubelet-cgroups=/systemd/system.slice
+KUBELET_EXTRA_ARGS=--cgroup-driver=systemd --runtime-cgroups=/systemd/system.slice  --fail-swap-on=false --kubelet-cgroups=/systemd/system.slice --config-dir=$kubelet_conf_d
 EOT
 
 # Enable userfaultfd for centos9 to support post-copy live migration.