uclalib_pgdbcreate.yml

---
#
# This play can be used to set-up a new postgresql database/user for
# use cases where a psql client does not need to be installed for the app
# to establish a connection.
#
# This play can also be used in situations where you need to set-up a
# postgresql database for an app running in a container. In this case,
# there is no host for ansible to connect.
#
# To use the play:
#   - Create a group_vars sub-directory with a unique name specific to this app
#   - Put the postgresql variable definitions in main.yml and main.vault.yml
#   - Run the ansible-playbook command:
#
#   $ ansible-playbook -i inventory.ini plays/uclalib_pgdbcreate.yml -e 'app_ansible_group=appgroupname' -v
#
#   Where `app_ansible_group` should be set to the name of the group_vars
#   sub-directory you created for this application.
#
# What is this play doing?
#    - The hosts parameter is hard-coded to localhost, which means this play can
#      only run on the system invoking the ansible-playbook command,
#      which is the ansible control server.
#    - The add_host task temporarily (for this play run only) adds localhost to
#      be a member of the group you identified in the command line extra parameters.
#    - With localhost now a member of this group, when the postgresql role runs,
#      all group_vars associated with this group will be included in the play.
#      These group_vars should include (at a minimum):
#          pgsql_major_version
#          pgsql_host
#          pgsql_name
#          pgsql_user
#          pgsql_pass
#      *Reference uclalib_role_postgresql for additional details*
#    - The postgresql role invocation includes the delegate_to parameter to
#      ensure the tasks run on the postgresql host identified in pgsql_host.
#

- name: uclalib_pgdbcreate.yml
  become: yes
  become_method: sudo
  hosts: localhost

  pre_tasks:
    - name: Add localhost to app-specific group for this play run
      add_host:
        hostname: "localhost"
        groups: "{{ app_ansible_group }}"

  roles:
    - { role: uclalib_role_postgresql, delegate_to: "{{ pgsql_host }}" }