install prereqs only when needed

provision.yml

@@ -28,9 +28,13 @@
   pre_tasks:
     - meta: end_play
       when: destroy_all is defined and destroy_all|bool
+    - name: check prereqs is already installed
+      shell: rpm -qa | grep -q python-modules-distutils
+      register: prereqs_found
+      changed_when: false
     - name: install prereqs
       raw: 'apt-get update && apt-get install -qy python2.7\(distutils\)'
-      when: destroy_all is not defined or not destroy_all
+      when: (destroy_all is not defined or not destroy_all) and (prereqs_found.rc != 0)
     - name: gather facts
       setup:
       when: destroy_all is not defined or not destroy_all