Fix unintentional trigger of ansible handlers

Due to an Ansible quirk, when one container of a group
changes, all containers in that group are restarted.
This can cause problems with some services.
The lower amount of containers restarted also speeds
up deploy and reconfigure.

Closes-bug: #1863510
Partially-implements: blueprint performance-improvements
Signed-off-by: Roman Krček <roman.krcek@tietoevry.com>
Change-Id: I699f9e7497bc1b384f383182d67233f3e0e165d1

ansible/roles/service-check-containers/tasks/main.yml

@@ -4,7 +4,6 @@
 - name: "{{ kolla_role_name | default(project_name) }} | Check containers"
   become: true
   vars:
-    service_name: "{{ item.key }}"
     service: "{{ item.value }}"
   kolla_container:
     action: "compare_container"
@@ -26,5 +25,13 @@
     command: "{{ service.command | default(omit) }}"
     cgroupns_mode: "{{ service.cgroupns_mode | default(omit) }}"
   with_dict: "{{ lookup('vars', (kolla_role_name | default(project_name)) + '_services') | select_services_enabled_and_mapped_to_host }}"
-  notify:
-    - "Restart {{ service_name }} container"
+  register: container_check
+
+# NOTE(yoctozepto): Must be a separate task because one cannot see the whole
+# result in the previous task and Ansible has a quirk regarding notifiers.
+# For details see https://github.com/ansible/ansible/issues/22579
+- name: "{{ kolla_role_name | default(project_name) }} | Notify handlers to restart containers"
+  debug:
+    msg: Notifying handlers
+  changed_when: container_check is changed
+  notify: "{{ container_check.results | select('changed') | map(attribute='item.key') | map('regex_replace', '^(.*)$', 'Restart \\1 container') | list }}"

releasenotes/notes/bug-1863510-e39da141cdd07c41.yaml

@@ -0,0 +1,8 @@
+---
+fixes:
+  - |
+    Fix unintentional trigger of ansible handlers.
+    Due to an Ansible quirk, when one container of a group
+    changes, all containers in that group are restarted.
+    This can cause problems with some services.
+    `LP#1863510 <https://launchpad.net/bugs/1863510>`__