[Prometheus] generated folder owns to prometheus user

Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>

group_vars/prometheus.yml

@@ -8,6 +8,7 @@ glob_service_prometheus_target:
   name: prometheus-target
   install_dir: /var/local/services/prometheus-target
   generated: true
+  generated_owner: prometheus
   cron:
     frequency: "*/10 * * * *"
     options: ""

roles/service/tasks/main.yml

@@ -38,7 +38,7 @@
     path: "{{ service.install_dir }}/generated"
     state: directory
     mode: "2770"
-    owner: root
+    owner: "{{ service.generated_owner|default(root) }}"
     group: _nounou
   when: service.generated is defined and service.generated