Add playbook to stop containers (stein only)

We need to stop several containers on the upgrades workflow.

This submission allows to reduce the duplicated code in THT.
It also handles the case in which we have podman as the CLI
but the containers running with docker.

The submission is proposed for tripleo-common only for
stable/stein, the master patch needs to be moved to the
tripleo-ansible repository as all the Ansible automation
is moved to that new repository.

Change-Id: I3c0580893aed5bda46d9104ffcee0f00cbabd9ee

roles/tripleo-container-stop/README.md

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+tripleo-container-stop
+======================
+
+An Ansible role to stop containers.
+
+Role variables
+--------------
+
+- tripleo_containers_to_stop: -- Containers names to stop.
+- tripleo_delegate_to: -- Delegate the execution of this role.
+
+Example Playbook
+----------------
+
+Sample playbook to call the role:
+
+  - name: Stop a set of container
+    hosts: all
+    roles:
+      - tripleo-container-stop
+    vars:
+      tripleo_containers_to_stop:
+        - nova_api
+        - nova_api_cron
+      tripleo_delegate_to: localhost
+
+License
+-------
+
+Free software: Apache License (2.0)
+
+Author Information
+------------------
+
+OpenStack TripleO team

roles/tripleo-container-stop/defaults/main.yaml

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+---
+tripleo_containers_to_stop: "{{ default([]) }}"
+tripleo_delegate_to: ["localhost"]

roles/tripleo-container-stop/tasks/container_stop.yaml

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+---
+- name: Make sure the container is stopped even if container_cli do not match
+  become: true
+  shell: |
+    # We need to make sure that containers are stopped
+    # as we might have different CLIs to interact with
+    # them. I.e the container_cli might be setted to be podman
+    # but we might have the containers running with docker.
+    set -eu
+    if command -v podman && podman exec {{ container }} /bin/true; then
+        systemctl stop tripleo_{{ container }}.service
+    fi
+    if type docker &> /dev/null && docker exec {{ container }} /bin/true; then
+        docker stop {{ container }}
+    fi
+  delegate_to: "{{ tripleo_delegate_to_item }}"
+  with_items: "{{ tripleo_delegate_to }}"
+  loop_control:
+    loop_var: tripleo_delegate_to_item

roles/tripleo-container-stop/tasks/main.yaml

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+---
+- include_tasks: "container_stop.yaml"
+  vars:
+    container: "{{ item }}"
+  with_items: "{{ tripleo_containers_to_stop }}"