- name: 'Provision a PostgreSQL server'
  hosts: "dbservers"
  sudo: yes
  sudo_user: postgres
  roles:
    - postgres

- name: Make sure the PostgreSQL users are present
  postgresql_user: name=rails password=secret role_attr_flags=CREATEDB,NOSUPERUSER
  sudo_user: postgres
  sudo: yes

postgres ALL=(ALL) NOPASSWD:ALL

ansible-playbook mail.yml -k -K