RabbitMQ use maintenance mode on container restart

Puts the RabbitMQ node into maintenance mode before restarting the
container. This will make the node shutdown less disruptive. For details
on what maintenance mode does, see:
https://www.rabbitmq.com/upgrade.html#maintenance-mode

Change-Id: Ia61573f3fb95fe8fcde6b789ca77ef5b45fe0a65

ansible/roles/rabbitmq/tasks/restart_services.yml

@@ -1,4 +1,21 @@
 ---
+- name: Get info on RabbitMQ container
+  become: True
+  kolla_container_facts:
+    container_engine: "{{ kolla_container_engine }}"
+    name: "rabbitmq"
+  register: container_info
+
+- name: Put RabbitMQ node into maintenance mode
+  kolla_toolbox:
+    container_engine: "{{ kolla_container_engine }}"
+    module_name: "community.rabbitmq.rabbitmq_upgrade"
+    module_args:
+      action: "drain"
+    user: root
+  become: true
+  when: container_info._containers | length > 0
+
 - name: Restart rabbitmq container
   vars:
     service_name: "rabbitmq"

releasenotes/notes/rabbitmq-use-maintenance-mode-on-restart-a25659b9269c82b5.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    When restarting a RabbitMQ container, the node is now first put into
+    maintenance mode. This will make the node shutdown less disruptive. For
+    details on what maintenance mode does, see:
+    https://www.rabbitmq.com/upgrade.html#maintenance-mode