Update epoxy upgrade doc (#1857)

Add section about Python 3.12 prerequisite

From Epoxy, Python 3.12 is required for Ansible control host.

* Remove Let's Encrypt section from known issues

The issue was resolved [1]

[1] https://review.opendev.org/c/openstack/kolla-ansible/+/957321

* Refer to beokay for creating kaybe env

Co-authored-by: Alex Welsh <112560678+Alex-Welsh@users.noreply.github.com>

Author: seunghun1ee

doc/source/operations/upgrading-openstack.rst

@@ -152,15 +152,6 @@ if using environments) to 3.43.1,
 or pulling all custom built images before destroying pulp then push them again
 after pulp upgrade is done.
 
-Let's Encrypt
--------------
-
-`Let's Encrypt TLS settings fix <https://review.opendev.org/c/openstack/kolla-ansible/+/925971>`__
-brought a breaking change to Let’s Encrypt ansible role. Now users have to explicitly set the target
-Let’s Encrypt ACME server as a kolla ansible variable ``letsencrypt_external_cert_server``/
-``letsencrypt_internal_cert_server`` if they were using Let’s Encrypt as a CA of their
-external/internal TLS certificates.
-
 Cinder
 ------
 
@@ -353,6 +344,34 @@ After the queue migration is finished, upgrade RabbitMQ to 4.1.
 
       kayobe kolla ansible run "rabbitmq-upgrade 4.1"
 
+.. _python-3-12:
+
+Python 3.12
+-----------
+
+From OpenStack 2025.1, Kayobe and Kolla-Ansible require Python 3.12.
+
+Ubuntu 24.04 has a default Python of version 3.12.
+You can find the upgrade procedure from :ref:`upgrading-to-ubuntu-noble`
+
+For Rocky Linux 9, install Python 3.12 manually.
+
+.. code-block:: bash
+
+   dnf install python3.12
+
+For both Operating Systems, Kayobe and Kolla-Ansible Python virtual environments
+created with older Python versions will not work with OpenStack 2025.1.
+
+Create a new Kayobe environment and bootstrap the Ansible control host with Python 3.12.
+Beokay is recommended when creating and managing the local Kayobe environment.
+You can find more information from the :ref:`beokay` documentation.
+
+.. note::
+
+   For Rocky Linux 9, ``beokay create`` must be used with the ``--python python3.12``
+   option to specify Beokay to use Python 3.12 as it is not the default.
+
 Preparation
 ===========
 
@@ -470,12 +489,19 @@ configuration.  The output of the command may be restricted using the
 Upgrading local Kayobe environment
 ----------------------------------
 
+.. warning::
+
+   Python 3.12 is required for OpenStack 2025.1 Kayobe environments.
+   The environment cannot be upgraded for this release, it must be rebuilt.
+   You can find more information at :ref:`python-3-12`
+
 The local Kayobe environment should be either recreated or upgraded to use the
 new release. It may be beneficial to keep a Kayobe environment for the old
-release in case it is necessary before the uprade begins.
+release in case it is necessary before the upgrade begins.
 
-In general it is safer to rebuild an environment than upgrade, but for
-completeness the following shows how to upgrade an existing local Kayobe
+In general it is safer to rebuild an environment than upgrade. You can follow
+instructions from the :ref:`beokay` documentation.
+But for completeness the following shows how to upgrade an existing local Kayobe
 environment.
 
 Change to the Kayobe configuration directory:

doc/source/usage.rst

@@ -58,6 +58,8 @@ The intention is to avoid merge conflicts where possible, but there may be
 cases where this is difficult. We are open to discussion on how best to
 approach this on both sides.
 
+.. _beokay:
+
 Beokay
 ------
 
@@ -88,6 +90,17 @@ Kayobe environments can also be specified, for example, to create an AIO environ
    --vault-password-file ~/vault-pw \
    --kayobe-in-requirements
 
+Python executable can also be specified, for example, to use Python 3.12:
+
+.. code-block:: console
+
+   beokay.py create \
+   --base-path skc-environment \
+   --kayobe-config-repo https://github.com/stackhpc/stackhpc-kayobe-config.git \
+   --kayobe-config-branch |current_release_git_branch_name| \
+   --kayobe-in-requirements
+   --python python3.12
+
 When Beokay environments are no longer required, they can be deleted by running:
 
 .. code-block:: console