commit 7fffe91d5aec9d1b06bd2754c2a846bb7e6fefa5
Author: Dmitriy Rabotyagov <dmitriy.rabotyagov@citynetwork.eu>
Date:   Fri Sep 25 18:35:18 2020 +0300

    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.
    
    Depends-On: https://review.opendev.org/755484
    Change-Id: If7f26c8020d4b02ab9e82dcb69a7ba91a3b5d145

diff --git a/defaults/main.yml b/defaults/main.yml
index c8a23a3..78ee1a1 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -243,3 +243,6 @@ trove_services:
     execstarts: "{{ trove_bin }}/trove-taskmanager"
     init_config_overrides: "{{ trove_taskmanager_init_config_overrides }}"
     start_order: 3
+
+_trove_is_first_play_host: "{{ (trove_services['trove-api']['group'] in group_names and inventory_hostname == (groups[trove_services['trove-api']['group']] | intersect(ansible_play_hosts)) | first) | bool }}"
+_trove_conductor_is_first_play_host: "{{ (trove_services['trove-conductor']['group'] in group_names and inventory_hostname == (groups[trove_services['trove-conductor']['group']] | intersect(ansible_play_hosts)) | first) | bool }}"
diff --git a/tasks/main.yml b/tasks/main.yml
index 1561e46..a03429c 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -37,8 +37,7 @@
 
 - import_tasks: db_setup.yml
   when:
-    - "trove_services['trove-api']['group'] in group_names"
-    - "inventory_hostname == ((groups[trove_services['trove-api']['group']]| intersect(ansible_play_hosts)) | list)[0]"
+    - _trove_is_first_play_host
   vars:
     _oslodb_setup_host: "{{ trove_db_setup_host }}"
     _oslodb_ansible_python_interpreter: "{{ trove_db_setup_python_interpreter }}"
@@ -55,8 +54,7 @@
 
 - import_tasks: mq_setup.yml
   when:
-    - "trove_services['trove-api']['group'] in group_names"
-    - "inventory_hostname == ((groups[trove_services['trove-api']['group']]| intersect(ansible_play_hosts)) | list)[0]"
+    - _trove_is_first_play_host
   vars:
     _oslomsg_rpc_setup_host: "{{ trove_oslomsg_rpc_setup_host }}"
     _oslomsg_rpc_userid: "{{ trove_oslomsg_rpc_userid }}"
@@ -169,12 +167,12 @@
       - name: "{{ trove_service_name }}"
         type: "{{ trove_service_type }}"
         description: "{{ trove_service_description }}"
-  when: inventory_hostname == groups['trove_api'][0]
+  when: _trove_is_first_play_host
   tags:
     - trove-install
 
 - import_tasks: trove_db_sync.yml
-  when: inventory_hostname == groups['trove_conductor'][0]
+  when: _trove_conductor_is_first_play_host
   tags:
     - trove-install