guest-overlay: Use OverlayFS instead of AuFS

guest-overlay/files/pam_mount.conf.xml

@@ -19,7 +19,9 @@
 
 <volume sgrp="gast" fstype="tmpfs" path="tmpfs" mountpoint="/guests/temporary" options="noatime,noexec,rw" />
 
-<volume path="none" sgrp="gast" fstype="aufs" mountpoint="/guests/home" options="br:/guests/temporary=rw:/guests/provision=ro,udba=reval" />
+<volume sgrp="gast" fstype="tmpfs" path="tmpfs" mountpoint="/guests/temporary_workdir" options="noatime,noexec,rw" />
+
+<volume path="none" sgrp="gast" fstype="overlay" mountpoint="/guests/home" options="lowerdir=/guests/provision,upperdir=/guests/temporary,workdir=/guests/temporary_workdir" />
 
 <!-- pam_mount parameters: General tunables -->
 

guest-overlay/tasks/main.yml

@@ -22,17 +22,16 @@
   tags:
     - guest-overlay
 
-- name: ensure aufs and pam-mount are available
+- name: ensure pam-mount available
   apt:
     name:
-      - aufs-tools
       - libpam-mount
     state: present
   tags:
     - guest-overlay
     - packages
 
-- name: ensure aufs mountpoints are available
+- name: ensure overlayfs mountpoints are available
   file:
     path: "/guests/{{ item }}"
     state: directory