rabbitmq: Do not stop containers on upgrade

Since RMQ 3.8 we can use rolling upgrade [1].

Depends-On: https://review.opendev.org/c/openstack/kolla/+/872393

[1]: https://www.rabbitmq.com/upgrade.html#rolling-upgrades

Change-Id: If6a7c6c12d9226a2406728108b3c87b3485ac55f

ansible/roles/rabbitmq/defaults/main.yml

@@ -118,3 +118,10 @@ rabbitmq_plugins:
     enabled: "{{ rabbitmq_enable_prometheus_plugin | bool }}"
 
 rabbitmq_enabled_plugins: "{{ rabbitmq_plugins | selectattr('enabled', 'equalto', true) | list }}"
+
+rabbitmq_feature_flags:
+  - "quorum_queue"
+  - "implicit_default_bindings"
+  - "virtual_host_metadata"
+  - "maintenance_mode_status"
+  - "user_limits"

ansible/roles/rabbitmq/tasks/deploy.yml

@@ -7,3 +7,5 @@
 
 - name: Flush handlers
   meta: flush_handlers
+
+- import_tasks: feature-flags.yml

ansible/roles/rabbitmq/tasks/feature-flags.yml

@@ -0,0 +1,10 @@
+---
+- name: Enable feature flags
+  kolla_toolbox:
+    container_engine: "{{ kolla_container_engine }}"
+    module_name: "community.rabbitmq.rabbitmq_feature_flag"
+    module_args:
+      name: "{{ item }}"
+    user: root
+  become: true
+  loop: "{{ rabbitmq_feature_flags }}"

ansible/roles/rabbitmq/tasks/upgrade.yml

@@ -1,44 +1,9 @@
 ---
-# NOTE(pbourke): These tasks perform a 'full stop upgrade', which is necessary when moving between
-# major releases. In future kolla-ansible releases we may be able to change this to a rolling
-# restart. For info on this process see https://www.rabbitmq.com/upgrade.html
-- name: Checking if rabbitmq container needs upgrading
-  vars:
-    service_name: "rabbitmq"
-    service: "{{ rabbitmq_services[service_name] }}"
-  become: true
-  kolla_docker:
-    action: "compare_image"
-    common_options: "{{ docker_common_options }}"
-    name: "{{ project_name }}"
-    image: "{{ rabbitmq_image_full }}"
-    environment: "{{ service.environment }}"
-  when: inventory_hostname in groups[role_rabbitmq_groups]
-  register: rabbitmq_differs
-
 - import_tasks: config.yml
 
+- import_tasks: feature-flags.yml
+
 - import_tasks: check-containers.yml
 
-- name: Stopping all rabbitmq instances but the first node
-  become: true
-  kolla_docker:
-    action: "stop_container"
-    common_options: "{{ docker_common_options }}"
-    name: "{{ project_name }}"
-  when:
-    - inventory_hostname != groups[role_rabbitmq_groups] | first
-    - rabbitmq_differs['result']
-
-- name: Stopping rabbitmq on the first node
-  become: true
-  kolla_docker:
-    action: "stop_container"
-    common_options: "{{ docker_common_options }}"
-    name: "{{ project_name }}"
-  when:
-    - inventory_hostname == groups[role_rabbitmq_groups] | first
-    - rabbitmq_differs['result']
-
 - name: Flush handlers
   meta: flush_handlers

releasenotes/notes/rabbitmq-upgrade-no-stop-5f41197623de3794.yaml

@@ -0,0 +1,5 @@
+---
+upgrade:
+  - |
+    Changes ``rabbitmq`` upgrade procedure from full stop of a cluster to
+    a rolling upgrade that is supported since RabbitMQ 3.8.