use postgres user to create postgres role and db (#28231)

Also install postgresql package.

clean.yml

@@ -77,4 +77,6 @@
         name: "{{item.value.db_name}}"
         state: absent
       with_dict: "{{apps}}"
+      become: yes
+      become_user: postgres
 

roles/app-setup/tasks/main.yml

@@ -8,6 +8,8 @@
   postgresql_db:
     name: "{{db_name}}"
     owner: "{{user}}"
+  become: yes
+  become_user: postgres
 
 - name: "{{app_name}} - conf directory"
   file:

roles/base/tasks/main.yml

@@ -1,33 +1,37 @@
 ---
-- name: Install system packages depedencies
+- name: Install system packages dependencies
   apt:
     name: "{{ item }}"
     state: present
   with_items:
+       - gettext
+       - graphicsmagick
+       - graphviz
        - inkscape
+       - libjs-leaflet
+       - libjs-pdf
        - libldap2-dev
        - libsasl2-dev
        - libssl-dev
        - make
        - nginx
+       - postgresql
        - python-dev
        - python-lasso
        - python-pip
-       - python-virtualenv
        - python-psycopg2
-       - gettext
+       - python-virtualenv
        - rabbitmq-server
        - ruby-sass
        - supervisor
-       - libjs-leaflet
-       - libjs-pdf
-       - graphicsmagick
-       - graphviz
   become: yes
 
 - name: "create the postgresql user named {{user}}"
   postgresql_user:
     name: "{{user}}"
+    role_attr_flags: CREATEDB,LOGIN
+  become: yes
+  become_user: postgres
 
 - name: create the virtualenv and install django
   pip: