Update /var/lib/nova directory permissions

The /var/lib/nova directory is world readable.
This may lead to sensitive information leakage and cloud compromise.

Set /var/lib/nova directory permissions to 0750.
Add libvirt-qemu user to nova group.

Change-Id: Ie4c98d6e54fa75efe4fff482b275b97e368c13ee
Related-Prod: https://mirantis.jira.com/browse/PROD-22088
diff --git a/nova/compute.sls b/nova/compute.sls
index 1b8c149..4cfe44f 100644
--- a/nova/compute.sls
+++ b/nova/compute.sls
@@ -50,6 +50,19 @@
     - libvirtd
 {%- endif %}
 
+user_libvirt-qemu:
+  user.present:
+  - name: libvirt-qemu
+  - groups:
+    - nova
+
+/var/lib/nova:
+  file.directory:
+    - user: nova
+    - group: nova
+    - dir_mode: 0750
+    - makedirs: True
+
 /var/lib/nova/.ssh/id_rsa:
   file.managed:
   - user: nova