Due to the nsenter and other reworks, it appears that

kubelet lost the ability to load kernel modules.  This
puts that back by adding the lib/modules mount to kubelet.

The new variable kubelet_load_modules can be set to true
to enable this item.  It is OFF by default.

roles/kubernetes/node/templates/kubelet-container.j2

@@ -14,6 +14,9 @@
   {% for dir in ssl_ca_dirs -%}
   -v {{ dir }}:{{ dir }}:ro \
   {% endfor -%}
+  {% if kubelet_load_modules is defined and kubelet_load_modules == true -%}
+  -v /lib/modules:/lib/modules:ro \
+  {% endif -%}
   -v /sys:/sys:ro \
   -v {{ docker_daemon_graph }}:/var/lib/docker:rw \
   -v /var/lib/kubelet:/var/lib/kubelet:shared \