Unhardcode service user/group uid/gid values
Warn to not change nova uid/gid values after user is created

Change-Id: Iaf4d6493c14175c3aea13035878cc185c1621bef
diff --git a/nova/compute.sls b/nova/compute.sls
index b2d0142..178f770 100644
--- a/nova/compute.sls
+++ b/nova/compute.sls
@@ -132,8 +132,9 @@
   {%- else %}
   - shell: /bin/false
   {%- endif %}
-  - uid: 303
-  - gid: 303
+  {# note: nova uid/gid values would not be evaluated after user is created. #}
+  - uid: {{ compute.get('nova_uid', 303) }}
+  - gid: {{ compute.get('nova_gid', 303) }}
   - system: True
   - groups:
     {%- if salt['group.info']('libvirtd') %}
@@ -149,7 +150,8 @@
 group_nova_compute:
   group.present:
     - name: nova
-    - gid: 303
+    {# note: nova gid value would not be evaluated after user is created. #}
+    - gid: {{ compute.get('nova_gid', 303) }}
     - system: True
     - require_in:
       - user: user_nova_compute
diff --git a/nova/controller.sls b/nova/controller.sls
index d6df274..2b19ba1 100644
--- a/nova/controller.sls
+++ b/nova/controller.sls
@@ -30,8 +30,9 @@
   - name: nova
   - home: /var/lib/nova
   - shell: /bin/false
-  - uid: 303
-  - gid: 303
+  {# note: nova uid/gid values would not be evaluated after user is created. #}
+  - uid: {{ controller.get('nova_uid', 303) }}
+  - gid: {{ controller.get('nova_gid', 303) }}
   - system: True
   - require_in:
     - pkg: nova_controller_packages
@@ -39,7 +40,8 @@
 group_nova:
   group.present:
     - name: nova
-    - gid: 303
+    {# note: nova gid value would not be evaluated after user is created. #}
+    - gid: {{ controller.get('nova_gid', 303) }}
     - system: True
     - require_in:
       - user: user_nova