optionnal api runtime extensions

roles/kubernetes/master/templates/manifests/kube-apiserver.manifest.j2

@@ -20,6 +20,11 @@ spec:
     - --tls-private-key-file={{ kube_cert_dir }}/apiserver-key.pem
     - --service-account-key-file={{ kube_cert_dir }}/apiserver-key.pem
     - --secure-port={{ kube_apiserver_port }}
+{% if kube_api_runtime_config is defined %}
+{%   for conf in kube_api_runtime_config %}
+    - --runtime-config={{ conf }}
+{%   endfor %}
+{% endif %}
     - --token-auth-file={{ kube_token_dir }}/known_tokens.csv
     - --v={{ kube_log_level | default('2') }}
     - --allow-privileged=true