bnr Prepare undercloud nfs ironic

Ansible playbook to configure the nfs service on the undercloud.
Export the directory needed and create the subdirectories
on the exported file.

Change-Id: I665913e32745907b7b41f73301e2aaf421722a40

tripleo_ansible/playbooks/cli-undercloud-prepare-ironic.yaml

@@ -0,0 +1,24 @@
+---
+#   Copyright 2021 Red Hat, Inc.
+#
+#   Licensed under the Apache License, Version 2.0 (the "License"); you may
+#   not use this file except in compliance with the License. You may obtain
+#   a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#   WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#   License for the specific language governing permissions and limitations
+#   under the License.
+
+- name: TripleO PXE installation and configuration.
+  hosts: Undercloud
+  remote_user: "{{ tripleo_target_user | default(lookup('env', 'USER')) }}"
+  become: true
+  vars:
+    tripleo_backup_and_restore_shared_storage_folder: "{{ tripleo_backup_and_restore_ironic_images_path }}"
+    tripleo_backup_and_restore_shared_storage_subfolders: ["pxelinux.cfg"]
+  roles:
+    - role: backup_and_restore