Ansible-role-postgresql: postgres no puede iniciar sesión para verificar la existencia de la base de datos

No estoy seguro de entender cómo o por qué el usuario postgres no puede iniciar sesión para verificar que la base de datos existe o no, pero el siguiente Playbook ...

---
- hosts: concourse_db
  roles:
    - role: geerlingguy.postgresql
      tags:
        - concourse_db
      vars:
        postgresql_restarted_state: "restarted"
        postgresql_service_state: started
        postgresql_service_enabled: true
        postgresql_hba_entries:
          - { type: local, database: all, user: postgres, auth_method: peer }
          - { type: local, database: all, user: all, auth_method: peer }
          - { type: host, database: all, user: all, address: '127.0.0.1/32', auth_method: md5 }
          - { type: host, database: all, user: all, address: '::1/128', auth_method: md5 }
        postgresql_locales:
          - 'en_US.UTF-8'
        postgresql_databases:
          - name: concourse
            owner: concourse
            login_user: postgres
            state: present
        postgresql_users:
          - name: concourse
            password: concoursepassword
            encrypted: true
            db: concourse
            login_user: postgres
            state: present
...

Dar los siguientes errores:

TASK [geerlingguy.postgresql : Ensure PostgreSQL is started and enabled on boot.] ***************************************************************************************************
ok: [10.144.0.137]

TASK [geerlingguy.postgresql : Ensure PostgreSQL databases are present.] ************************************************************************************************************
An exception occurred during task execution. To see the full traceback, use -vvv. The error was: ProgrammingError: role "concourse" does not exist
failed: [10.144.0.137] (item={'name': 'concourse', 'owner': 'concourse', 'login_user': 'postgres', 'state': 'present'}) => {"changed": false, "item": {"login_user": "postgres", "name": "concourse", "owner": "concourse", "state": "present"}, "msg": "Database query failed: role \"concourse\" does not exist\n"}
    to retry, use: --limit @/Users/pd028300/Documents/development/Ansible/concourse_ci_playbook/playbook_2.retry

No estoy seguro de si se supone que debe usar postgres usuario o el usuario que creé, concourse en este caso.

Archivo de requisitos de Ansible-Galaxy

---
# https://galaxy.ansible.com/geerlingguy/postgresql
- src: geerlingguy.postgresql
  version: 1.4.5
...

Información del sistema de destino

[email protected]:~ ( concourse-ci-db.novalocal )
12:38:42 $ uname -a
Linux concourse-ci-db.novalocal 3.10.0-957.1.3.el7.x86_64 #1 SMP Mon Nov 26 17:43:08 PST 2018 x86_64 x86_64 x86_64 GNU/Linux
[email protected]:~ ( concourse-ci-db.novalocal )
12:38:44 $ cat /etc/oracle-release
Oracle Linux Server release 7.6

Versiones de Ansible y Ansible Playbook

$ ansible --version && ansible-playbook --version
ansible 2.7.6
  config file = /Users/pd028300/Documents/development/Ansible/concourse_ci_playbook/ansible.cfg
  configured module search path = ['/Users/pd028300/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/pd028300/.pyenv/versions/3.7.2/lib/python3.7/site-packages/ansible
  executable location = /Users/pd028300/.pyenv/versions/3.7.2/bin/ansible
  python version = 3.7.2 (default, Jan 22 2019, 09:35:39) [Clang 9.0.0 (clang-900.0.39.2)]
ansible-playbook 2.7.6
  config file = /Users/pd028300/Documents/development/Ansible/concourse_ci_playbook/ansible.cfg
  configured module search path = ['/Users/pd028300/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/pd028300/.pyenv/versions/3.7.2/lib/python3.7/site-packages/ansible
  executable location = /Users/pd028300/.pyenv/versions/3.7.2/bin/ansible-playbook
  python version = 3.7.2 (default, Jan 22 2019, 09:35:39) [Clang 9.0.0 (clang-900.0.39.2)]