From 5ce463551aeda103d218d4bc66347facaa625fcf Mon Sep 17 00:00:00 2001
From: Vincent Legoll <vincent.legoll@iphc.cnrs.fr>
Date: Thu, 13 Mar 2025 13:54:52 +0100
Subject: [PATCH] Fix ansible `difference()` filter use

The `difference()` filter inputs a list, and takes another list as
parameter, computes a set difference between the two, and returns
the resulting (unordered) list.

This is documented here:
https://docs.ansible.com/ansible/latest/collections/ansible/builtin/difference_filter.html

This filter was changed in:
https://github.com/ansible/ansible/commit/7d3d4572edcb4e436883a9aca2859f620077390a

The behaviour changed in ansible-core between 2.15 and 2.16:

```
    ################################################################
    ### Testing ansible-core==2.16
    ################################################################

    PLAY [Test ansible difference filter] ******************************************

    TASK [debug] *******************************************************************
    ok: [localhost] => {
        "msg": "diff with a string: ['one', 'two', 'six'] | difference('two')   => ['one', 'six', 'two']"
    }

    TASK [debug] *******************************************************************
    ok: [localhost] => {
        "msg": "diff with a list:   ['one', 'two', 'six'] | difference(['two']) => ['one', 'six']"
    }

    PLAY RECAP *********************************************************************
    localhost                  : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

    ################################################################
    ### Testing ansible-core==2.15
    ################################################################

    PLAY [Test ansible difference filter] ******************************************

    TASK [debug] *******************************************************************
    ok: [localhost] => {
        "msg": "diff with a string: ['one', 'two', 'six'] | difference('two')   => ['one', 'six']"
    }

    TASK [debug] *******************************************************************
    ok: [localhost] => {
        "msg": "diff with a list:   ['one', 'two', 'six'] | difference(['two']) => ['one', 'six']"
    }

    PLAY RECAP *********************************************************************
    localhost                  : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0
```

The above was generated by using: https://github.com/vincent-legoll/test_ansible_diff

Closes-Bug: #2096936
Change-Id: I7a57c829803fc5baa8b1d3a1805c102f04b8ab2c
Signed-off-by: Vincent Legoll <vincent.legoll@iphc.cnrs.fr>
(cherry picked from commit ca89c07cd4f1b187460630f2ccb308e02815065e)
---
 templates/nova.conf.j2 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/templates/nova.conf.j2 b/templates/nova.conf.j2
index b291e0a7..f652d92e 100644
--- a/templates/nova.conf.j2
+++ b/templates/nova.conf.j2
@@ -211,7 +211,7 @@ memcache_security_strategy = ENCRYPT
 memcache_secret_key = {{ memcached_encryption_key }}
 {% endif %}
 
-{% if group_names | intersect(nova_services.keys() | difference('nova-compute') | map('extract', nova_services, 'group') | list) | count > 0 %}
+{% if group_names | intersect(nova_services.keys() | difference(['nova-compute']) | map('extract', nova_services, 'group') | list) | count > 0 %}
 [database]
 connection = mysql+pymysql://{{ nova_galera_user }}:{{ nova_container_mysql_password }}@{{ nova_galera_address }}:{{ nova_galera_port }}/{{ nova_galera_database }}?charset=utf8{% if nova_galera_use_ssl | bool %}&ssl_verify_cert=true{% if nova_galera_ssl_ca_cert | length > 0 %}&ssl_ca={{ nova_galera_ssl_ca_cert }}{% endif %}{% endif %}