move flexvolume plugin directory creation to preinstall (#4999)

* move flexvolume plugin directory creation to preinstall

* changes per pr feedback

roles/kubernetes/preinstall/defaults/main.yml

@@ -25,6 +25,7 @@ kube_cert_group: kube-cert
 kube_config_dir: /etc/kubernetes
 kube_cert_dir: "{{ kube_config_dir }}/ssl"
 kube_cert_compat_dir: /etc/kubernetes/pki
+kubelet_flexvolumes_plugins_dir: /usr/libexec/kubernetes/kubelet-plugins/volume/exec
 
 # Container Linux by CoreOS cloud init config file to define /etc/resolv.conf content
 # for hostnet pods and infra needs

roles/kubernetes/preinstall/tasks/0040-set_facts.yml

@@ -178,3 +178,13 @@
     etcd_deployment_type: host
   when:
     - etcd_kubeadm_enabled
+
+- name: check /usr readonly
+  stat:
+    path: "/usr"
+  register: usr
+
+- name: set alternate flexvolume path
+  set_fact:
+    kubelet_flexvolumes_plugins_dir: /var/lib/kubelet/volumeplugins
+  when: not usr.stat.writeable

roles/kubernetes/preinstall/tasks/0050-create_directories.yml

@@ -22,6 +22,7 @@
     - "{{ kube_cert_dir }}"
     - "{{ kube_manifest_dir }}"
     - "{{ kube_script_dir }}"
+    - "{{ kubelet_flexvolumes_plugins_dir }}"
 
 - name: Check if kubernetes kubeadm compat cert dir exists
   stat: