From c4d5649b11912637c8ca4753358747fc1b695d3e Mon Sep 17 00:00:00 2001
From: Dmitriy Rabotyagov <dmitriy.rabotyagov@citynetwork.eu>
Date: Mon, 14 Sep 2020 16:32:10 +0300
Subject: [PATCH] Define condition for the first play host one time

We use the same condition, which defines against what host some "service"
tasks should run against, several times. It's hard to keep it the same
across the role and ansible spending additional resources to evaluate
it each time, so it's simpler and better for the maintenance to set
a boolean variable which will say for all tasks, that we want to run
only against signle host, if they should run or not now.

Change-Id: Ic7277f4d3c6697a5be2fa86e07f8b19f0c5db069
---
 handlers/main.yml              | 3 +--
 tasks/main.yml                 | 9 +++------
 tasks/neutron_db_setup.yml     | 4 ++--
 tasks/neutron_post_install.yml | 2 +-
 vars/main.yml                  | 2 ++
 5 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/handlers/main.yml b/handlers/main.yml
index d4cdc99b..a37e5b90 100644
--- a/handlers/main.yml
+++ b/handlers/main.yml
@@ -56,8 +56,7 @@
   delegate_to: "{{ groups[neutron_services['neutron-server']['group']][0] }}"
   when:
     - "ansible_local['openstack_ansible']['neutron']['need_db_contract'] | bool"
-    - "neutron_services['neutron-server']['group'] in group_names"
-    - "inventory_hostname == ((groups[neutron_services['neutron-server']['group']] | intersect(ansible_play_hosts)) | list)[0]"
+    - "_neutron_is_first_play_host"
   listen:
     - "Restart neutron services"
     - "venv changed"
diff --git a/tasks/main.yml b/tasks/main.yml
index 596ab330..4e730658 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -34,8 +34,7 @@
 
 - import_tasks: db_setup.yml
   when:
-    - "neutron_services['neutron-server']['group'] in group_names"
-    - "inventory_hostname == ((groups[neutron_services['neutron-server']['group']] | intersect(ansible_play_hosts)) | list)[0]"
+    - "_neutron_is_first_play_host"
   vars:
     _oslodb_setup_host: "{{ neutron_db_setup_host }}"
     _oslodb_ansible_python_interpreter: "{{ neutron_db_setup_python_interpreter }}"
@@ -52,8 +51,7 @@
 
 - import_tasks: mq_setup.yml
   when:
-    - "neutron_services['neutron-server']['group'] in group_names"
-    - "inventory_hostname == ((groups[neutron_services['neutron-server']['group']]| intersect(ansible_play_hosts)) | list)[0]"
+    - "_neutron_is_first_play_host"
   vars:
     _oslomsg_rpc_setup_host: "{{ neutron_oslomsg_rpc_setup_host }}"
     _oslomsg_rpc_userid: "{{ neutron_oslomsg_rpc_userid }}"
@@ -208,8 +206,7 @@
         type: "{{ neutron_service_type }}"
         description: "{{ neutron_service_description }}"
   when:
-    - "neutron_services['neutron-server']['group'] in group_names"
-    - "inventory_hostname == ((groups[neutron_services['neutron-server']['group']] | intersect(ansible_play_hosts)) | list)[0]"
+    - "_neutron_is_first_play_host"
   tags:
     - neutron-config
 
diff --git a/tasks/neutron_db_setup.yml b/tasks/neutron_db_setup.yml
index 0f7d8dde..2ca65cc4 100644
--- a/tasks/neutron_db_setup.yml
+++ b/tasks/neutron_db_setup.yml
@@ -19,7 +19,7 @@
   become_user: "{{ neutron_system_user_name }}"
   when:
     - "ansible_local['openstack_ansible']['neutron']['need_db_expand'] | bool"
-    - "inventory_hostname == ((groups[neutron_services['neutron-server']['group']] | intersect(ansible_play_hosts)) | list)[0]"
+    - "_neutron_is_first_play_host"
 
 - name: Disable the db expand fact
   ini_file:
@@ -35,7 +35,7 @@
   become: yes
   become_user: "{{ neutron_system_user_name }}"
   when:
-    - "inventory_hostname == ((groups[neutron_services['neutron-server']['group']] | intersect(ansible_play_hosts)) | list)[0]"
+    - "_neutron_is_first_play_host"
   changed_when: false
   register: _offline_migrations_check
   failed_when:
diff --git a/tasks/neutron_post_install.yml b/tasks/neutron_post_install.yml
index ff8bdc07..ff457ff6 100644
--- a/tasks/neutron_post_install.yml
+++ b/tasks/neutron_post_install.yml
@@ -100,7 +100,7 @@
     flat: yes
   changed_when: false
   with_items: "{{ neutron_core_files }}"
-  run_once: true
+  when: _neutron_is_first_play_host
 
 - name: Copy common neutron config
   config_template:
diff --git a/vars/main.yml b/vars/main.yml
index 26b9ffcc..47bd1ae6 100644
--- a/vars/main.yml
+++ b/vars/main.yml
@@ -13,6 +13,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+_neutron_is_first_play_host: "{{ (neutron_services['neutron-server']['group'] in group_names and inventory_hostname == (groups[neutron_services['neutron-server']['group']] | intersect(ansible_play_hosts)) | first) | bool }}"
+
 ###
 ### Open vSwitch
 ###