add support for EventRateLimit plugin configuration (#8711)

* feat: add support for EventRateLimit admission plugin

* docs: add documentation about admission_control_config_file and EventRateLimit configuration

roles/kubernetes/control-plane/templates/admission-controls.v1beta2.yaml.j2

@@ -0,0 +1,9 @@
+apiVersion: apiserver.config.k8s.io/v1
+kind: AdmissionConfiguration
+plugins:
+{% for plugin in kube_apiserver_enable_admission_plugins[0].split(',') %}
+{% if plugin in kube_apiserver_admission_plugins_needs_configuration %}
+- name: {{ plugin }}
+  path: {{ kube_config_dir }}/{{ plugin|lower }}.yaml
+{% endif %}
+{% endfor %}

roles/kubernetes/control-plane/templates/eventratelimit.v1beta2.yaml.j2

@@ -0,0 +1,11 @@
+apiVersion: eventratelimit.admission.k8s.io/v1alpha1
+kind: Configuration
+limits:
+{% for limit in kube_apiserver_admission_event_rate_limits.values() %}
+- type: {{ limit.type }}
+  qps: {{ limit.qps }}
+  burst: {{ limit.burst }}
+{% if limit.cache_size is defined %}
+  cacheSize: {{ limit.cache_size }}
+{% endif %}
+{% endfor %}

roles/kubernetes/control-plane/templates/kubeadm-config.v1beta2.yaml.j2

@@ -126,6 +126,9 @@ apiServer:
 {% if kube_apiserver_enable_admission_plugins|length > 0 %}
     enable-admission-plugins: {{ kube_apiserver_enable_admission_plugins | join(',') }}
 {% endif %}
+{% if kube_apiserver_admission_control_config_file %}
+    admission-control-config-file: {{ kube_config_dir }}/admission-controls.yaml
+{% endif %}
 {% if kube_apiserver_disable_admission_plugins|length > 0 %}
     disable-admission-plugins: {{ kube_apiserver_disable_admission_plugins | join(',') }}
 {% endif %}
@@ -249,6 +252,13 @@ apiServer:
     readOnly: false
 {% endif %}
 {% endif %}
+{% if kube_apiserver_admission_control_config_file %}
+  - name: admission-control-configs
+    hostPath: {{ kube_config_dir }}/admission-controls
+    mountPath: {{ kube_config_dir }}
+    readOnly: false
+    pathType: DirectoryOrCreate
+{% endif %}
 {% for volume in apiserver_extra_volumes %}
   - name: {{ volume.name }}
     hostPath: {{ volume.hostPath }}