Make salt.minion.grains idempotent (poor man solution)

salt/minion/grains.sls

@@ -14,24 +14,34 @@ salt_minion_grains_dir:
     - {{ minion.install_state }}
 
 salt_minion_grains_placeholder:
-  file.touch:
+  file.managed:
   - name: /etc/salt/grains.d/placeholder
+  - replace: false
   - require:
     - file: salt_minion_grains_dir
 
+{#
+  TODO: we need to be idempotent but reload salt-minion when grains are
+  changed. So for now, adding new grains requires removal of /etc/salt/grains
+  file and execution of salt state again
+  This can be possibly solved by custom module for grains management or native
+  support for grains.d in salt
+#}
 salt_minion_grains_file:
   cmd.run:
   - name: cat /etc/salt/grains.d/* > /etc/salt/grains
+  - creates: /etc/salt/grains
   - require:
     - file: salt_minion_grains_placeholder
   - watch_in:
     - service: salt_minion_service
 
 salt_minion_grains_publish:
-  module.run:
+  module.wait:
   - name: mine.send
   - name: grains.items
-  - require:
+  - watch:
+    - service: salt_minion_service
     - cmd: salt_minion_grains_file
 
 {%- endif %}