[root@ansible-tower ansible-tower-setup-3.1.4]# more restore.yml
---
- hosts: database
  gather_facts: false
  tasks:
    - name: Temporarily grant createdb role
      postgresql_user:
        name: awx
        role_attr_flags: CREATEDB
      become: yes
      become_user: postgres

- hosts: tower:!tower[0]
  gather_facts: false
  tasks:
    - name: Stop Tower services on all nodes
      command: ansible-tower-service stop

- hosts: tower[0]
  gather_facts: yes
  roles:
    - role: check_config_static
    - role: config_dynamic
    - role: restore
      restore_database: "{{ config_dynamic_database }}"
      restore_pg_database: "{{ pg_database }}"

- hosts: tower:!tower[0]
  gather_facts: false
  tasks:
    - name: Start Tower services on all nodes
      command: ansible-tower-service start

- hosts: database
  gather_facts: false
  tasks:
    - name: Revoke createdb role
      postgresql_user:
        name: awx
        role_attr_flags: NOCREATEDB
      become: yes
      become_user: postgres

[root@ansible-tower restore]# head -20 tower.db
--
-- PostgreSQL database dump
--
DROP DATABASE awx;
CREATE DATABASE awx WITH TEMPLATE = template0 ENCODING = 'UTF8' LC_COLLATE = 'en_US.UTF-8' LC_CTYPE = 'en_US.UTF-8';
ALTER DATABASE awx OWNER TO awx;

[root@ansible-tower ansible-tower-setup-3.1.4]# more roles/restore/tasks/postgres.yml
---
# use dbname 'template1' to connect to the remote database
# Since we drop the database as part of our backup/restore, we can't use the awx
# database for this command.
- name: Perform a PostgreSQL restore (external).
  shell: "psql --host='{{ tower_db_settings.default.HOST }}' --port={{ tower_db_settings.default.PORT }} --username='{{ tower_db_settings.default.USER
  }}' --dbname='template1' < ./tower.db"
  args:
    chdir: '{{ backup_dir.rstrip("/") }}/restore/'
  environment:
    PGPASSWORD: "{{ tower_db_settings.default.PASSWORD }}"
  no_log: True
  when: "restore_database == 'external'"