From a9f5d9767242d617751a270db2f66cf98038c789 Mon Sep 17 00:00:00 2001
From: Dmitriy Rabotyagov <noonedeadpunk@ya.ru>
Date: Tue, 6 Oct 2020 18:14:34 +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: I78d44704a0224b2c73832a607e84ea8d9499f8c2
---
 tasks/main.yml | 12 ++++--------
 vars/main.yml  |  2 ++
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/tasks/main.yml b/tasks/main.yml
index 75b287e3..40d11ddd 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -71,8 +71,7 @@
 
 - import_tasks: db_setup.yml
   when:
-    - "nova_services['nova-conductor']['group'] in group_names"
-    - "inventory_hostname == ((groups[nova_services['nova-conductor']['group']] | intersect(ansible_play_hosts)) | list)[0]"
+    - _nova_is_first_play_host
   vars:
     _oslodb_setup_host: "{{ nova_db_setup_host }}"
     _oslodb_ansible_python_interpreter: "{{ nova_db_setup_python_interpreter }}"
@@ -97,8 +96,7 @@
 
 - import_tasks: mq_setup.yml
   when:
-    - "nova_services['nova-conductor']['group'] in group_names"
-    - "inventory_hostname == ((groups[nova_services['nova-conductor']['group']] | intersect(ansible_play_hosts)) | list)[0]"
+    - _nova_is_first_play_host
   vars:
     _oslomsg_rpc_setup_host: "{{ nova_oslomsg_rpc_setup_host }}"
     _oslomsg_rpc_userid: "{{ nova_oslomsg_rpc_userid }}"
@@ -172,15 +170,13 @@
         type: "{{ nova_service_type }}"
         description: "{{ nova_service_description }}"
   when:
-    - "nova_services['nova-conductor']['group'] in group_names"
-    - "inventory_hostname == ((groups['nova_conductor'] | intersect(ansible_play_hosts)) | list)[0]"
+    - _nova_is_first_play_host
   tags:
     - nova-config
 
 - import_tasks: nova_db_setup.yml
   when:
-    - "nova_services['nova-conductor']['group'] in group_names"
-    - "inventory_hostname == ((groups['nova_conductor'] | intersect(ansible_play_hosts)) | list)[0]"
+    - _nova_is_first_play_host
   tags:
     - nova-config
 
diff --git a/vars/main.yml b/vars/main.yml
index fb6d4c6a..ee677634 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.
 
+_nova_is_first_play_host: "{{ (nova_services['nova-conductor']['group'] in group_names and inventory_hostname == (groups[nova_services['nova-conductor']['group']] | intersect(ansible_play_hosts)) | first) | bool }}"
+
 nova_venv_packages: |-
   {%- set pkg_list = nova_pip_packages | union(nova_user_pip_packages) %}
   {%- if nova_oslomsg_amqp1_enabled | bool %}