Horizon: inability to override policies with ansible 6+

[Andriy Kurilin]

Kolla-ansible fails to override horizon policies files due to possible bug regression in ansible lib (https://github.com/ansible/ansible/issues/39389) that affects list concatenation using "set_fact" and "with_items".

Validation by CI: https://review.opendev.org/c/openstack/kolla-ansible/+/901761

Ansible release: 6+
Kolla-Ansible: 2023.1+ (required ansible 6)

Traceback:

```
Traceback (most recent call last):
  File "/home/zuul/kolla-ansible-venv/lib/python3.10/site-packages/ansible/plugins/action/template.py", line 94, in run
    source = self._find_needle('templates', source)
  File "/home/zuul/kolla-ansible-venv/lib/python3.10/site-packages/ansible/plugins/action/__init__.py", line 1455, in _find_needle
    return self._loader.path_dwim_relative_stack(path_stack, dirname, needle)
  File "/home/zuul/kolla-ansible-venv/lib/python3.10/site-packages/ansible/parsing/dataloader.py", line 341, in path_dwim_relative_stack
    raise AnsibleFileNotFound(file_name=source, paths=[to_native(p) for p in search])
ansible.errors.AnsibleFileNotFound: Could not find or access '[] + [ '/etc/kolla/config/horizon/neutron_policy.yaml' ] + [ '/etc/kolla/config/horizon/nova_policy.yaml' ]'
Searched in:
 /home/zuul/kolla-ansible-venv/share/kolla-ansible/ansible/roles/horizon/templates/[] + [ '/etc/kolla/config/horizon/neutron_policy.yaml' ] + [ '/etc/kolla/config/horizon/nova_policy.yaml' ]
 /home/zuul/kolla-ansible-venv/share/kolla-ansible/ansible/roles/horizon/[] + [ '/etc/kolla/config/horizon/neutron_policy.yaml' ] + [ '/etc/kolla/config/horizon/nova_policy.yaml' ]
 /home/zuul/kolla-ansible-venv/share/kolla-ansible/ansible/roles/horizon/tasks/templates/[] + [ '/etc/kolla/config/horizon/neutron_policy.yaml' ] + [ '/etc/kolla/config/horizon/nova_policy.yaml' ]
 /home/zuul/kolla-ansible-venv/share/kolla-ansible/ansible/roles/horizon/tasks/[] + [ '/etc/kolla/config/horizon/neutron_policy.yaml' ] + [ '/etc/kolla/config/horizon/nova_policy.yaml' ]
 /home/zuul/kolla-ansible-venv/share/kolla-ansible/ansible/templates/[] + [ '/etc/kolla/config/horizon/neutron_policy.yaml' ] + [ '/etc/kolla/config/horizon/nova_policy.yaml' ]
 /home/zuul/kolla-ansible-venv/share/kolla-ansible/ansible/[] + [ '/etc/kolla/config/horizon/neutron_policy.yaml' ] + [ '/etc/kolla/config/horizon/nova_policy.yaml' ] on the Ansible Controller.
If you are using a module and expect the file to exist on the remote, see the remote_src option
```

[Andriy Kurilin (andreykurilin)]

From IRC (discovered by fricker):
https://github.com/ansible/ansible/issues/80404 + https://docs.ansible.com/ansible-core/2.14/porting_guides/porting_guide_core_2.13.html#playbook

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/kolla-ansible/+/902659

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/kolla-ansible/+/902659
Committed: https://opendev.org/openstack/kolla-ansible/commit/97cd173177c88f08e62fa4b4f57a3c34a46f1c2a
Submitter: "Zuul (22348)"
Branch: master

commit 97cd173177c88f08e62fa4b4f57a3c34a46f1c2a
Author: Andrey Kurilin <email address hidden>
Date: Thu Nov 23 15:24:08 2023 +0100

    Fix broken list concatenation in horizon role

    Starting with ansible-core 2.13, list concatenation format is changed
    and does not support concatenation operations outside of the jinja template.

    The format change:

      "[1] + {{ [2] }}" -> "{{ [1] + [2] }}"

    This affects the horizon role that iterates over existing policy files to
    override and concatenate them into a single variable.

    Co-Authored-By: Dr. Jens Harbott <email address hidden>

    Closes-Bug: #2045660
    Change-Id: I91a2101ff26cb8568f4615b4cdca52dcf09e6978

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/2023.2
Review: https://review.opendev.org/c/openstack/kolla-ansible/+/902821

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/2023.1
Review: https://review.opendev.org/c/openstack/kolla-ansible/+/902822

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/kolla-ansible/+/902821
Committed: https://opendev.org/openstack/kolla-ansible/commit/6ba26e7a1349b008221c5b494fab8635a9557d2b
Submitter: "Zuul (22348)"
Branch: stable/2023.2

commit 6ba26e7a1349b008221c5b494fab8635a9557d2b
Author: Andrey Kurilin <email address hidden>
Date: Thu Nov 23 15:24:08 2023 +0100

    Fix broken list concatenation in horizon role

    Starting with ansible-core 2.13, list concatenation format is changed
    and does not support concatenation operations outside of the jinja template.

    The format change:

      "[1] + {{ [2] }}" -> "{{ [1] + [2] }}"

    This affects the horizon role that iterates over existing policy files to
    override and concatenate them into a single variable.

    Co-Authored-By: Dr. Jens Harbott <email address hidden>

    Closes-Bug: #2045660
    Change-Id: I91a2101ff26cb8568f4615b4cdca52dcf09e6978
    (cherry picked from commit 97cd173177c88f08e62fa4b4f57a3c34a46f1c2a)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/kolla-ansible 17.0.0.0rc2 release candidate.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/kolla-ansible/+/902822
Committed: https://opendev.org/openstack/kolla-ansible/commit/aa860978ac121f01b9f84b24eb997b1438022ad8
Submitter: "Zuul (22348)"
Branch: stable/2023.1

commit aa860978ac121f01b9f84b24eb997b1438022ad8
Author: Andrey Kurilin <email address hidden>
Date: Thu Nov 23 15:24:08 2023 +0100

    Fix broken list concatenation in horizon role

    Starting with ansible-core 2.13, list concatenation format is changed
    and does not support concatenation operations outside of the jinja template.

    The format change:

      "[1] + {{ [2] }}" -> "{{ [1] + [2] }}"

    This affects the horizon role that iterates over existing policy files to
    override and concatenate them into a single variable.

    Co-Authored-By: Dr. Jens Harbott <email address hidden>

    Closes-Bug: #2045660
    Change-Id: I91a2101ff26cb8568f4615b4cdca52dcf09e6978
    (cherry picked from commit 97cd173177c88f08e62fa4b4f57a3c34a46f1c2a)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/kolla-ansible 16.3.0 release.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/zed
Review: https://review.opendev.org/c/openstack/kolla-ansible/+/915018

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/kolla-ansible/+/915018
Committed: https://opendev.org/openstack/kolla-ansible/commit/4d649e3daf6b1055d8e2e5cd30fec6866cf9ae8b
Submitter: "Zuul (22348)"
Branch: stable/zed

commit 4d649e3daf6b1055d8e2e5cd30fec6866cf9ae8b
Author: Andrey Kurilin <email address hidden>
Date: Thu Nov 23 15:24:08 2023 +0100

    Fix broken list concatenation in horizon role

    Starting with ansible-core 2.13, list concatenation format is changed
    and does not support concatenation operations outside of the jinja template.

    The format change:

      "[1] + {{ [2] }}" -> "{{ [1] + [2] }}"

    This affects the horizon role that iterates over existing policy files to
    override and concatenate them into a single variable.

    Co-Authored-By: Dr. Jens Harbott <email address hidden>

    Closes-Bug: #2045660
    Change-Id: I91a2101ff26cb8568f4615b4cdca52dcf09e6978
    (cherry picked from commit 97cd173177c88f08e62fa4b4f57a3c34a46f1c2a)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/kolla-ansible zed-eom release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/kolla-ansible 18.0.0.0rc1 release candidate.